/***************************** MISSION TEMPLATE *******************************/ /* MODIFICATIONS: */ /* 920929 RMONARREZ */ /* Generated from database */ /* Template: Mission Template Rev: 19890121 */ /* Note: The following templates form part of a standard set */ /* for the submission of a mission to the PDS. */ /* Hierarchy: MISSION */ /* MSNINFO */ /* MSNPHSINFO */ /* MSNREFINFO */ /* REFERENCE */ /* REFAUTHORS */ OBJECT = MISSION MISSION_NAME = "PIONEER VENUS" OBJECT = MSNINFO MISSION_START_DATE = 1978-05-20 MISSION_STOP_DATE = 1992-10-07 MISSION_ALIAS_NAME = "P12" MISSION_DESC = " Pioneer Venus Overview Pioneer Venus consists of two basic spacecraft: Orbiter and Multiprobe [1]. The latter was separated into five separate vehicles near Venus. These were the probe transporter (called the Bus), a large atmospheric entry probe (dubbed Sounder) and three identical smaller probes (called North, Day, and Night in accordance with their entry locations). At Venus all six spacecraft communicated directly back to the Earth-based Deep Space Network (DSN) and, in the case of the Multiprobe mission, to two special receiving sites near Guam and Santiago (Chile). The Orbiter was launched on May 20, 1978, encountered Venus on December 4, 1978, was inserted into orbit on that same day after a Type II interplanetary cruise trajectory lasting 198 days and covering more than 500 x 106 km. Twelve scientific experiments were included in the instrumentation payload and a few radioscience investigations were planned using the S-band telemetry signal carrier and a special X-band beacon included as part of the spacecraft hardware. Scientific observations were made both in-cruise and in-orbit. The nominal in-orbit mission was designed to extend for one Venus year (243 days). At the time this Special Issue was submitted for publication the nominal mission was complete and the Orbiter was continuing into an extended mission phase. It appears that sufficient fuel remains to permit full operation through calendar year 1980, at least. During the nominal mission all but two experiments operated 100 percent successfully. One, the Radar Mapper, produced unusable data for a 32-day period from December 18, 1978 to January 19, 1979. the data lost will be acquired during the extended Orbiter mission. The other, the Infrared Radiometer, failed to operate after February 14, 1979, but had collected and enormous quantity of valuable information prior to that date. The Multiprobe was launched on August 8, 1978, encountered Venus on December 9, 1978 (just five days following the Orbiter insertion) after a Type I interplanetary cruise trajectory lasting 123 days and covering 330 x 106 km. The Sounder was released from the Bus on November 15, 1978, and the three small probes were released simultaneously on November 19, 1978. All probes entered(200-km altitude) the Venus upper atmosphere within a time span of about 11 min and descended to the surface in a period from 53 to 56 min, all the time performing scientific observations. The Bus made a delayed (~90 min) entry relative to the probes into Venus' upper atmosphere and burned up at about 110-km altitude since it was not protected, as were the probes, with entry heat shields. Scientific observations were made during the one-minute interval from 700 to 110 km. Although not designed for `survival' after impact, the Day probe managed to transmit for over 67 min on the surface (it in fact continued to transmit after the Bus transmission ceased). Seven scientific experiments were included in the Sounder instrumentation payload, three identical experiments in each small probe, and two in the Bus. Again, radioscience experiments were performed using, separately or together, the S-band telemetry signal carriers emanating from the spacecraft and received at the Earth-based tracking stations. In general, all instruments performed nominally, although certain instruments behaved anomalously on all four probes near the surface. The scientific payload, Principal Investigator, and his affiliation are listed in Table I for each Pioneer Venus spacecraft. This Special Issue is primarily devoted to short descriptions of the instruments listed. All are contained herein with one exception: Orbiter Cloud Photopolarimeter. Detailed instrument descriptions for this experiment have been published [2]. Before proceeding with descriptions of the individual instruments, four special archival-type reports are included. The first deals with spacecraft design and operation [3]. The Pioneer Venus spacecraft were unique and very special design features and operational modes needed to be incorporated. These are summarized therein. Similarly, telemetry recovery, particularly for the Multiprobe mission, was unusually demanding and unique techniques were developed and employed. The Orbiter and Multiprobe systems are described in two papers [4], [5]. Finally, a special ground data handling and distribution system, developed after an Atmospheric Explorer program model, was developed and is described [6]. Only one radioscience experiment description is specifically presented [7]. The necessary information for the others are contained in the telemetry recovery papers [3], [4]. It should be noted that neither the scientific objectives nor the scientific results for the Pioneer Venus program are described or discussed in detail. The objectives have been published elsewhere [8], [9]. The reader is referred to two special journal issues devoted to initial scientific results published to data [10], [11]. References [1] L. Colin and C.F. Hall, Space Sci. Rev., vol. 20, no. 3, p. 283, May 1977. [2] E.E. Russell, L. A. Watts, S. F. Pellicori, and D. L. Coffeen, 'Orbiter cloud photopolarimeter for the Pioneer Venus mission,' Proc. Soc. Photo-Optical Instrum. Eng., vol. 112, Aug. 1977. L. D. Travis, 'Imaging and polarimetry with the Pioneer Venus orbiter cloud photopolarimeter,' Proc. Photo-Optical Instrum. Eng., vol. 183, 1979. [3] G. J. Nothwang, 'Pioneer Venus Spacecraft Design and Operation,' IEEE Trans. on Geosci. and Remote Sensing, vol. GE-18, no. 1 pp 5-10, January, 1980. [4] A. L. Berman and R. Ramos, 'Pioneer Venus Occultation Radio Science Data Generation,' IEEE Trans. on Geosci. and Remote Sensing, vol. GE-18, no. 1 pp 11-14. [5] R. B. Miller and R. Ramos, 'Pioneer Multiprobe Entry Telemetry Recovery,' IEEE Trans. on Geosci. and Remote Sensing, vol. GE-18, no. 1 pp 15-19, January, 1980. [6] J. A. Ferandin, J. Brownwood, C. Weeks, and R. Pak, 'Pioneer Venus Unified Abstract Data Library and Quick Look Data Delivery System,' IEEE Trans. on Geosci. and Remote Sensing, vol. GE-18, no. 1 pp 19-27, January, 1980. [7] J. R. Smith and R. Ramos, 'Data Acquisition for Measuring the Wind on Venus from Pioneer Venus', IEEE Trans. on Geosci. and Remote Sensing, vol. GE-18, no. 1 pp 126-130, January, 1980. [8] Space Sci. Rev., vol. 20 no. 3, May 1977. [9] Space Sci. Rev., vol. 20 no. 4, June 1977. [10] Science, vol. 203 no. 4382, Feb. 23 1979. [11] Science, vol. 205 no. 4401, July 6 1979." MISSION_OBJECTIVES_SUMMARY = " The two Pioneer flights to Venus were intended to explore the atmosphere of the planet, to study its surface using radar, and to determine its global shape and internal density distribution. The Pioneer Venus Orbiter was designed to operate for 8 months or more making direct and remote sensing measurements. The Pioneer Venus Multiprobe spacecraft was designed to separate into 5 separate atmospheric entry craft some 12.9 million km (8 million miles) before reaching Venus. Each probe craft was designed to make measurements of the characteristics of the atmosphere from its highest regions to the surface of the planet in a period of a little more than 2 hours at points spread over the Earth-facing hemisphere of the planet." OBJECT = MSNPHSINFO SPACECRAFT_ID = PVO TARGET_NAME = VENUS MISSION_PHASE_TYPE = "ORBITAL OPERATIONS" SPACECRAFT_OPERATIONS_TYPE = "ORBITER OPERATIONS" MISSION_PHASE_START_TIME = 1978-12-05 MISSION_PHASE_STOP_TIME = 1992-10-07 MISSION_PHASE_DESC = " This mission phase 'orbiter operations' describes the entire mission of the Orbiter spacecraft." END_OBJECT = MSNPHSINFO OBJECT = MSNPHSINFO SPACECRAFT_ID = PVMP TARGET_NAME = VENUS MISSION_PHASE_TYPE = ENCOUNTER SPACECRAFT_OPERATIONS_TYPE = "ATMOSPHERIC PROBE" MISSION_PHASE_START_TIME = 1978-12-07 MISSION_PHASE_STOP_TIME = 1978-12-07 MISSION_PHASE_DESC = " This mission phase 'encounter' describes all operations of the 5 separate probe components of the Multiprobe component of the Pioneer Venus mission." END_OBJECT = MSNPHSINFO END_OBJECT = MSNINFO OBJECT = MSNREFINFO REFERENCE_KEY_ID = "COLIN1980B" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "MISSION DESCRIPTION" JOURNAL_NAME = "IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Colin, L., 'Pioneer Venus Overview', IEEE Transactions on Geoscience and Remote Sensing, January 1980, Vol. GE-18, No. 1, p5-10" OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LAWRENCE COLIN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE REFERENCE_KEY_ID = "COLIN&HALL1977" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "MISSION DESCRIPTION" JOURNAL_NAME = "SPACE SCIENCE REVIEW" PUBLICATION_DATE = 1977 REFERENCE_DESC = " Colin, L. and C. F. Hall, Space Sci. Rev., vol. 20, no. 3, p. 283, May 1977." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LAWRENCE COLIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "C. F. HALL" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE REFERENCE_KEY_ID = "RESSELLETAL1977" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "MISSION DESCRIPTION" JOURNAL_NAME = "PHOTO-OPTICAL INSTRUM. ENG." PUBLICATION_DATE = 1977 REFERENCE_DESC = " Russell, E. E., L. A. Watts, S. F. Pellicori, and D. L. Coffeen, 'Orbiter cloud photopolarimeter for the Pioneer Venus mission,' Proc. Soc. Photo-Optical Instrum. Eng., vol. 112, Aug. 1977." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "E. E. RUSSELL" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "L. A. WATTS" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "S. F. PELLICORI" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. L. COFFEEN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE REFERENCE_KEY_ID = "TRAVIS1979" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "MISSION DESCRIPTION" JOURNAL_NAME = "PHOTO-OPTICAL INSTRUM. ENG." PUBLICATION_DATE = 1979 REFERENCE_DESC = " Travis, L. D., 'Imaging and polarimetry with the Pioneer Venus orbiter cloud photopolarimeter,' Proc. Photo-Optical Instrum. Eng., vol. 183, 1979." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "L. D. TRAVIS" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE REFERENCE_KEY_ID = "NOTHWANG1980" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "MISSION DESCRIPTION" JOURNAL_NAME = "IEEE TRANS. ON GEOSCI. & REMOTE SENSING" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Nothwang, G. J., 'Pioneer Venus Spacecraft Design and Operation,' IEEE Trans. on Geosci. and Remote Sensing, vol. GE-18, no. 1 pp 5-10, January, 1980." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. J. NOTHWANG" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE REFERENCE_KEY_ID = "BERMAN&RAMOS1980" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "MISSION DESCRIPTION" JOURNAL_NAME = "IEEE TRANS. ON GEOSCI. & REMOTE SENSING" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Berman A. L., and R. Ramos, 'Pioneer Venus Occultation Radio Science Data Generation,' IEEE Trans. on Geosci. and Remote Sensing, vol. GE-18, no. 1 pp 11-14." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. L. BERMAN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. RAMOS" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE REFERENCE_KEY_ID = "MILLER&RAMOS1980" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "MISSION DESCRIPTION" JOURNAL_NAME = "IEEE TRANS. ON GEOSCI. & REMOTE SENSING" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Miller, R. B., and R. Ramos, 'Pioneer Multiprobe Entry Telemetry Recovery,' IEEE Trans. on Geosci. and Remote Sensing, vol. GE-18, no. 1 pp 15-19, January, 1980." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. B. MILLER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. RAMOS" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE REFERENCE_KEY_ID = "FERANDINETAL1980" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "MISSION DESCRIPTION" JOURNAL_NAME = "IEEE TRANS. ON GEOSCI. & REMOTE SENSING" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Ferandin, J. A., J. Brownwood, C. Weeks, and R. Pak, 'Pioneer Venus Unified Abstract Data Library and Quick Look Data Delivery System,' IEEE Trans. on Geosci. and Remote Sensing, vol. GE-18, no. 1 pp 19-27, January, 1980." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. A. FERANDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. BROWNWOOD" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "C. WEEKS" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. PAK" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE REFERENCE_KEY_ID = "SMITH&RAMOS1980" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "MISSION DESCRIPTION" JOURNAL_NAME = "IEEE TRANS. ON GEOSCI. & REMOTE SENSING" PUBLICATION_DATE = 1980 REFERENCE_DESC = " J. R. Smith and R. Ramos, 'Data Acquisition for Measuring the Wind on Venus from Pioneer Venus', IEEE Trans. on Geosci. and Remote Sensing, vol. GE-18, no. 1 pp 126-130, January, 1980. OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. R. SMITH" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. RAMOS" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE REFERENCE_KEY_ID = "SSRV20N3" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "MISSION DESCRIPTION" JOURNAL_NAME = "SPACE SCIENCE REVIEW" PUBLICATION_DATE = 1977 REFERENCE_DESC = " Space Sci. Rev., vol. 20 no. 3, May 1977." END_OBJECT = REFERENCE REFERENCE_KEY_ID = "SSRV20N4" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "MISSION DESCRIPTION" JOURNAL_NAME = "SPACE SCIENCE REVIEW" PUBLICATION_DATE = 1977 REFERENCE_DESC = " Space Sci. Rev., vol. 20 no. 4, June 1977." END_OBJECT = REFERENCE REFERENCE_KEY_ID = "SCIENCEV203N4382" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "MISSION DESCRIPTION" JOURNAL_NAME = "SCIENCE" PUBLICATION_DATE = 1979 REFERENCE_DESC = " Science, vol. 203 no. 4382, Feb. 23 1979." END_OBJECT = REFERENCE REFERENCE_KEY_ID = "SCIENCEV205N4401" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "MISSION DESCRIPTION" JOURNAL_NAME = "SCIENCE" PUBLICATION_DATE = 1977 REFERENCE_DESC = " Science, vol. 205 no. 4401, July 6 1979." END_OBJECT = REFERENCE END_OBJECT = MSNREFINFO END_OBJECT = MISSION /*********************** SPACECRAFT TEMPLATE **********************************/ /* MODIFICATIONS: */ /* Template: Spacecraft Template Rev: 19890121 */ /* Note: The following templates form part of a standard */ /* set for the submission of a spacecraft to the PDS. */ /* Hierarchy: SPACECRAFT */ /* SCINFO */ /* PLATFORM */ /* SCREFINFO */ /* REFERENCE */ /* REFAUTHORS */ OBJECT = SPACECRAFT SPACECRAFT_ID = "PVO" OBJECT = SCINFO LAUNCH_DATE = 1978-05-20 INSTRUMENT_HOST_NAME = "PIONEER VENUS ORBITER" INSTRUMENT_HOST_TYPE = "SPACECRAFT" SPACECRAFT_DESC = " Extracted from: `Pioneer Venus Spacecraft Design and Operation' IEEE Transactions on Geoscience and Remote Sensing, vol. GE-18, No. 1, January 1980 By George J. Nothwang I. Introduction The Pioneer Venus mission objectives dictated the requirement for two spacecraft designs designated the Orbiter and the Multiprobe. (The Multiprobe is defined as the Bus with the one Large Probe and three identical Small Probes attached in the launch/cruise configuration.) The conceptual designs of these spacecraft resulted from Phase B studies conducted from October 1972 to July 1973, and after selection of the spacecraft contractor, Hughes Aircraft Company, in February 1974, a spacecraft conceptual design review was conducted in November 1974. The Orbiter and Multiprobe utilized the same designs to the maximum extent possible to minimize costs. In addition, designs of subsystems or portions of subsystems from previous spacecraft designs (such as OSO and Intelsat) were utilized to the maximum extent possible with little or no modifications. This commonality in the two spacecraft designs also resulted in certain amounts of commonality in ground test equipment and test software as well as commonality in spacecraft flight operations and associated software. A photograph of the Multiprobe (foreground) and Orbiter in the manufacturer's facility (Hughes Aircraft Company, El Segundo, CA) is shown on the cover. II. Spacecraft Design and Operation The design and operation of the orbiter will be described first and the Multiprobe second. The Multiprobe description and operation will then be separated into the Bus, Large Probe, and Small Probe segments. A. Orbiter The general configuration of the Orbiter after launch by an Atlas SLV-3D/Centaur D-1 AR is shown in Fig. 1. The weight of the spacecraft and 12 scientific instruments immediately after separation from the launch vehicle was 553 kg (1220 lbs) which included 32 kg (70 lbs) of hydrazine for trajectory correction maneuvers and spin axis orientation and 179 kg (398 lbs) of orbit insertion motor solid propellant and inserts. Immediately after separation from the Centaur launch vehicle, the spacecraft was automatically spun up to approximately 6.5 rpm and after establishing satisfactory ground communications with the Deep Space Network (DSN), commands to deploy the magnetometer boom and to orient the spacecraft spin axis perpendicular to the ecliptic were transmitted. The nominal spin rate was increased to 15 rpm with the spin axis (+Z axis) pointed in a northerly direction and this attitude was maintained in the cruise phase of the mission except during short periods for trajectory corrections. Communications were normally maintained through the despun high-gain antenna to maximize the data rates. Two days before reaching Venus, the spacecraft was configured for orbit insertion. Communications were transferred to the omni antennas and the spacecraft including the high- gain antenna spun up to 52 rpm to provide acceptable gyroscopic stiffness during motor burn. Since the motor burn had to occur while the spacecraft was being occulted by Venus, commands were loaded and subsequently executed from the on-board stored command logic without real-time communication. Orbit insertion was achieved with an orbit inclination of 105 degrees with respect to the equator and a nominal orbit period of 24 h. After reacquisition of the spacecraft from occultation, a series of maneuvers were performed to point the spacecraft spin axis (=Z axis) perpendicular to the ecliptic in a southerly direction, despin the high-gain antenna, and slow the spacecraft spin rate to about 5 rpm, the preferred rate for scientific data. Nominal orbital operations were then begun which include orbit periapsis and period adjustments and spacecraft attitude adjustments. The Orbiter spacecraft consists of the following subsystems and functions: Mechanical function (including the Spacecraft Structure), Thermal Function (accomplished by the Structure/Harness Subsystem), Controls Subsystem, Propulsion Subsystem, Data Handling subsystem, Command Subsystem, Communications Subsystem, and Power Subsystem. 1) Mechanical: The mechanical features of the spacecraft can be described by six basic assemblies, as seen in Fig. 1. The despun antenna assembly, the bearing and power transfer assembly (BAPTA), the BAPTA support structure, equipment shelf, substrate (solar array), orbit insertion motor (OIM) and its case, and thrust tube. The shape and equipment layout conform to the basic mechanical requirements of a spin-stabilized vehicle. The solar cells on the cylindrical solar panel, antenna orientations, and thrust vector orientations provide efficient power, communications, and maneuverability while the Orbiter is spinning in its cruise and orbit attitudes. 2) Thermal: The thermal design is based on isolating the equipment from the external solar extremes experienced during the mission. (Solar intensity increases by a factor 1.98 from Earth to Venus). Commandable heaters are provided to maintain the orbit insertion motor and safe and arm device within their specified temperature ranges, to prevent possible freezing and hydrazine monopropellant , and to make up heat balance should there occur an inadvertent trip of nonessential spacecraft loads. Fifteen thermostatically controlled thermal louvers are mounted on the aft side of the equipment shelf beneath units having high dissipations. 3) Controls: The controls subsystem provides the sensing logic and actuators to accomplish the following stabilization, control, and reference functions: a) spin axis attitude determination (via use of slit field-of-view type sun sensors and star sensors and star sensors), science roll reference signals generation, and spin period measurements; b) control of thrusters for spin axis attitude maneuvers , spin speed control, and spacecraft velocity maneuvers; c) high-gain antenna azimuth despin control and elevation positioning to a desired earth line-of- sight pointing ; additionally, antenna slew control for open-loop tracking of the Earth line-of- sight; d) magnetometer sensor deployment; e) nutational damping, via use of a partially filled tube of liquid Freon E3. 4) Propulsion: The propulsion subsystem provides the hydrazine monopropellant storage, pressurization, distribution lines, isolation valves, filtering, and thruster assemblies used to accomplish Orbiter maneuvers throughout the mission. 5) Data Handling: The data handling subsystem conditions and integrates into command- selectable (choice of thirteen fixed and one programmable) formats, all analog and digital telemetry data (248 assigned channels) originating in the subsystems and science instruments. The selected format of the all-digitized data modulates a 16 384-Hz subcarrier at a command- selectable (choice of thirteen rates between 8 and 4096 bps) bit rate. The resulting information is routed to the communications subsystem for modulation of the downlink S-band carrier. The data handling subsystem includes a data memory, consisting of two data storage units (DSU) that is intended primarily for use during any occultation. Data are stored or read out at the commanded bit rate. Each DSU has a capacity of 524 288 bits (equivalent to 1024 telemetry minor frames). 6) Command: The command subsystem decodes all commands received via the communications subsystem at the fixed rate of 4 bps, and either stores the command for later execution or routes the command in real time to the addressed destination. Each of the 381 assigned commands is either completely decoded (discrete-type command) by the command subsystem and the execution command generated, or is partially decoded (quantitative-type command) by the command subsystem and the command is routed to the addressed destination for final decoding. 7) Communications: The communications subsystem provides radiation reception and transmission capabilities for the command and telemetry information. The uplink command capability is maintained by modulating an S-band carrier of approximately 2.115 GHz. The downlink telemetry modulates an S-band carrier approximately 2.295 GHz. There are two redundant reception channels; each includes a hemispherically omnidirectional antenna (aft or forward) that spatially supplements the other to produce total spatial coverage. Optionally by command, the forward antenna is replaceable by a high-gain antenna or a high-gain back-up antenna. The S-band downlink is assignable by command to any one of the aft or forward omnidirectional antennas, or to the high-gain or high-gain back-up (directional) antennas. Its frequency is a multiple of the uplink frequency; or in the absence of an uplink signal, it is a multiple of a crystal oscillator located in the receiver. The downlink may also be transmitted via any one of, or some pairs of, four 10-W power amplifiers. There is an additional transmitter in the X-band range (the frequency is 11/3 of the S-band downlink frequency) that is for use in occultation measurements. The transmission is unmodulated through the high-gain antenna only. 8) Power: The power subsystem provides semiregulated 28 V 10 percent to all spacecraft loads (including science instruments). The primary source of power is the main solar array. When the solar panel output cannot provide adequate power for all spacecraft loads (at low sun angles and during eclipses), the two nickel/cadmium batteries (each rated at 7.5 Ah full capacity) come on line automatically through the discharge regulators. Battery energy is replenished through a small boost charge array. The power interface unit provides power switching for the propulsion heaters and OIM heaters. It also contains fuses for these circuits and the science instruments input power lines. Power is distributed on four separate power buses. If a spacecraft over-current condition or under-voltage on either battery occurs, loads are removed to protect the spacecraft from potential catastrophic failure by tripping off buses in the following sequence: science, switched loads, and transmitter. This leaves only those loads that are absolutely essential to spacecraft survival in a continuously powered ON mode. The RF transmitters and exciters are on the transmitter bus. Controls and data handling units are on the switched loads bus. Scientific instruments are on the science bus. Command units, OIM and propulsion heaters, power conditioning units, and spacecraft receivers are on the essential bus. Excitation for the pyro bus is derived from a battery tap located 16 cells (of a total of 24) from the ground reference level. The bus voltage is limited to 30.0 V by seven shunt limiters that dissipate all excess solar panel capacity in load resistors mounted on the solar panel substrate and equipment shelves." END_OBJECT = SCINFO OBJECT = PLATFORM PLATFORM_OR_MOUNTING_NAME = "MAGNETOMETER BOOM" PLATFORM_OR_MOUNTING_DESC = " An 4.8 meter long boom (188.9 inches) that was unfurled and extended automatically after launch. The magnetometer boom is located 240 degrees from the X-axis of the spacecraft coordinate system, measured in towards the Y-axis (in the spin direction) of the spin plane (XY). The total distance from the end of the boom to the orbiter spin axis is 5.94 meters (234.0 inches)" END_OBJECT = PLATFORM OBJECT = SCREFINFO REFERENCE_KEY_ID = NOTHWANG1980 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "SPACECRAFT DESIGN" JOURNAL_NAME = "IEEE TRANS. ON GEOSCIENCE & REMOTE SENSING" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Nothwang, G.T., `Pioneer Venus Spacecraft Design and Operation', IEEE Transactions on Geoscience and Remote Sensing, January 1980, Vol. GE-18, No. 1, p5-10" OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "GEORGE J. NOTHWANG" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = SCREFINFO END_OBJECT = SPACECRAFT /***************** ONMS Instrument Catalog Template ***************************/ /* Template: Spacecraft Instrument Template Rev: 19890121 */ /* Note: The following templates form part of a standard */ /* set for the submission of a spacecraft instrument */ /* to the PDS. */ /* */ /* Hierarchy: SCINSTRUMENT */ /* INSTINFO */ /* INSTDETECT */ /* INSTELEC */ /* INSTFILTER */ /* INSTOPTICS */ /* SCINSTOFFSET */ /* INSTSECTION */ /* INSTSECTINFO */ /* INSTSECTFOVS */ /* INSTSECTPARM */ /* INSTSECTDET */ /* INSTSECTELEC */ /* INSTSECTFILT */ /* INSTSECTOPTC */ /* INSTMODEINFO */ /* INSTMODESECT */ /* INSTREFINFO */ /* REFERENCE */ /* REFAUTHORS */ OBJECT = SCINSTRUMENT SPACECRAFT_ID = PVO INSTRUMENT_ID = ONMS /* Template: Instrument Information Template Rev: 19890121 */ /* Note: This template shall be completed for the */ /* instrument id entered in the ebinstrument or */ /* scinstrument template. */ /* */ OBJECT = INSTINFO INSTRUMENT_NAME = "ORBITER NEUTRAL MASS SPECTROMETER" INSTRUMENT_TYPE = "QUADRUPOLE MASS SPECTROMETER" PI_PDS_USER_ID = HNIEMANN NAIF_DATA_SET_ID = "N/A" BUILD_DATE = 1977 INSTRUMENT_MASS = 3.8 INSTRUMENT_HEIGHT = 28 INSTRUMENT_LENGTH = 35 INSTRUMENT_WIDTH = 15 INSTRUMENT_MANUFACTURER_NAME = "Goddard Space Flight Center" INSTRUMENT_SERIAL_NUMBER = "Flight Unit" INSTRUMENT_DESC = " The ONMS instrument is a quadrupole mass spectrometer with an electron impact ion source for measurement of neutral gas composition in the mass range 1 to 46 amu. The sensor consists of an ion source, a quadrupole mass filter and secondary electron multiplier as an ion detector. The ion source is partially enclosed and exposed to the ambient atmosphere of neutral and ion particles through an entrance aperture. Just inside the aperture is the ion repeller grid at 36 V above spacecraft ground designed to reject ions of this energy or less. On either side of the ion repeller grid is a grid at -4.3 V designed to reject low energy electrons. Neutral gas particles are not influenced by these grid potentials. They pass through to the ionization region where a small fraction are ionized by electron impact from an electrostatically focused electron beam generated by a hot filament. The ions are then focused into the quadrupole analyzer for separation according to mass to charge ratio. The ion source grid assembly can also function as a retarding potential analyzer (RPA) for analysis of direct streaming particles that have not had any surface collisions. With the filament off and the ion repeller set to 0 V, the sensor can detect thermal ions. With the ion repeller set to 36 V, superthermal ions exceeding this energy can be detected. There are two selectable electron energies which can be used to identify neutral species based on the mass spectral cracking patterns. The ionization and dissociation cross sections are a function of electron energy. Mass spectra are simplified at lower electron energy but with a considerable loss in ionization efficiency. The ion source enclosure is such that it can function as a closed or an open source. The neutral particle density in the ionization region consists of direct streaming particles and particles which have been reflected from the surfaces. As a closed source, the neutral particle flux into the enclosure is balanced by the thermalized flux exiting the enclosure. The thermalized flux results from particles colliding many times with the ion source surfaces. This increased ram pressure results in a significant increase (about 60 for N2) over the ambient pressure of the species and lowers the detection threshold. Species such as O and N chemically react on the surfaces forming O2 and NO. The open source measures direct streaming particles that have not had surface collisions. The view cone for the open source in the ionization region has a half angle of about 38 degrees. The detection threshold for this mode is higher than that for the closed source since the ambient density is directly detected. A retarding potential field is used to discriminate between direct streaming particles at spacecraft energy and surface reflected particles at a much lower energy. A radio frequency electromagnetic field is used to select a given mass to charge ratio ion. Mass peak (mass/charge ratio) selection is accomplished through a proper combination of the ac and dc voltages applied to the hyperbolic rods. Resolution is determined by the ratio of the ac to dc amplitude. The peaks produced are flat topped and stepping from one mass peak to the other can be accomplished without requiring peak searching. A secondary electron multiplier is used as a detector operating either in a pulse counting mode or a current measuring mode. Either value can be output to the telemetry stream. Normally the pulse counter values are output as long as the electrometer current does not exceed a given value. The sensor itself is constructed of stainless steel and was sealed under vacuum prior to delivery for launch. A small ion getter pump was used to maintain the vacuum below 1.E-4 pascal. The ion source was covered by a metal-ceramic break-off cap which was removed by a pyrotechnic actuator after orbit insertion. The basic instrument data consists of a mass number being sampled, pulse counter or electrometer data, RPA mode type, and housekeeping data. Proper operation of the instrument is verified through its housekeeping data. Data accumulation is always done at equally spaced time intervals. Each 16 bit telemetry represents one reading obtained over an integration time determined by the spacecraft bit rate and format. The individual 8 bit telemetry words assigned to the ONMS in a minor frame are not equally spaced in time. Therefore, the data has to be stored internally for a period of time and then sent to the telemetry. The storage and readout are accomplished through the use of two memories. One memory is reading out unequally spaced data to the spacecraft telemetry system while the other is accumulating equally spaced data from the instrument. Both memories are first in, first out (FIFO) type and are switched simultaneously. The time interval over which the ONMS data is accumulated in memory depends on the spacecraft bit rate, format, and spin segment status. With no spin segment, the memories are switched on at a minor frame beginning, data is accumulated for one minor frame and then read out to the telemetry system during the next minor frame. With spin segment mode commanded, the data is accumulated at four times the rate of the no spin segment mode and at equally spaced time intervals from -45 degrees to +45 degrees roll angle relative to the ONMS velocity ram direction. The memory switch time and data accumulation start time are determined from the spacecraft RAM pulse, which is assumed to represent the maximum velocity ram for the spacecraft +X axis (0 degrees spacecraft azimuth angle), and the ONMS azimuth angle. The ONMS has telemetry words in the formats PERC (6 words), PERB (14 words), and APOB (2 words). Each word consists of 8 bits. The length of the data cycle for housekeeping data is 128 words. The unit of 64 16-bit words contains all of the information to determine the current command status, monitor values, etc., and is the basic unit of processing for the data. In addition to the internal monitors read out by the instrument electronics, other monitors are available from the spacecraft telemetry which do not require the ONMS to be operating: instrument temperature, bus voltage and instrument on/off status. A summary of the instrument parameters are as follows: Ion source: closed/open with particle retarding deployment by metal-ceramic break off cap, pyrotechnically activated electron impact ionization dual filaments, 20 ua emission electron energy 27 eV or 70 eV Analyzer: quadrupole mass filter, hyperbolic rods 7.5 cm long, field radius 0.2 cm rf frequency 5.6 mhz Detector: secondary electron multiplier, copper-beryllium, box and grid design pulse counting up to about 852000 counts/sec (0.160 ua current) current measurement from 0.160 ua to 15 ua minimum detectable signal is 1 count per integration period multiplier noise signal < 1 count / minute Total detector dynamic range: 1.3E7 Resolution/crosstalk: < 1.E-4 Mass range: 1 to 46 amu Mass measurement modes: programmed mass, 8 individual mass numbers, 1 to 46 amu unit sweep, 1 to 46 in steps of 1 amu 1/8 unit sweep, 1 to 46 in steps of 0.125 amu Sample rates: a) Normal mode equally time spaced samples for all spacecraft spin angles 6 samples/sec with nominal bit rate 1024 bits/sec and PERC format actual sample rate dependent on spacecraft telemetry format and bit rate used b) Spin segment mode equally time spaced samples for 45 degrees with respect to occurrence of velocity ram effective data rate 4 times the normal rate Number of words in telemetry format per minor frame: PERB: 14 8-bit words PERC: 6 8-bit words APOB: 2 8-bit words 1 minor frame = 64*8 bits Integration time: 0.171875 s maximum, 0.006 s minimum dependent upon telemetry bit rate and format The spacecraft orbit is nearly polar (105.6 degrees inclination) with periapsis near the equator (17 degrees north celestial latitude) and has an average period of 24.03 hours. The local time of periapsis increases 1.6 degrees/day (or orbit) so that it takes 224.7 days to sample one complete diurnal cycle (dayside, evening terminator, nightside, and morning terminator). For the first 600 orbits, the altitude of periapsis varied from 142 km to 250 km. After this period, the periapsis altitude was no longer controlled and increased in altitude as a result of solar gravitational perturbations. The spacecraft spins with a nominal period of 12 seconds about an axis which points approximately toward the south ecliptic pole. INSTRUMENT MODES Currently there are three distinct types of data that can be acquired by the ONMS instrument: Neutral density, superthermal ion flux and thermal ion density. Independent of these three data types, there are a number of modes in which the data can be taken as well as a number of modes in which the instrument can be configured and tuned. Generally speaking these different modes correspond to different command configurations of the instrument. Data measurement types: Neutral gas composition: closed source open source with particle retarding Ion composition: superthermal ions > 36 eV relative to spacecraft ground (ion repeller set to 36 V) normal ions > 0 V relative to spacecraft ground (ion repeller set to 0 V) Detection ranges{(1)}: Neutral composition: N2 sensitivity: 5.E4 (particles/cm**3) / (count/sec) Open source density range: 3.E5 to 4.E12 particles/cm**3 for N2 Closed source density range: 5.E3 to 7.E10 particles/cm**3 for N2 Superthermal (>36 eV) ions: O+ sensitivity: 4.E3 (particles/cm**2/sec)/(count/sec) O+ flux range for 40 eV ions: 2.E4 to 3.E11 particles/cm**2/sec O+ density range for 40 eV ions: 0.01 to 1.E5 particles/cm**3 Thermal ions: O+ sensitivity: 0.02 (particles/cm**3)/(counts/sec), normalized to OIMS O+ density range: 0.02 to 2.6E5 particles/cm**3 for a spacecraft speed of 9.6 km/s (1) Based on minimum count rate, detector dynamic range and instrument sensitivity for mode used The instrument configuration modes: a) Ion source: Two different electron energies can be selected by command. Ions can also be measured with the filament off. An ion repeller grid just inside the entrance aperture at 36 V or 0 V rejects positive ions of this energy or less. Neutral gas particles are not affected by the 36 V grid potential and pass through into the ionization region. b) Retarding potential analyzer: Retarding and non-retarding modes can be commanded separately along with a mode in which they alternate. A retarding potential sweep through a range of retarding voltages is also commandable and is considered an engineering diagnostic tool. The retarding voltage is VR=O+G*M where the offset O and and the gain G each have 4 separate commandable levels, and M is the mass number in amu. The retarding sweep voltage is VR=O+0.0103*(64-S) where D is a fixed value and S is number 1...64. For reference a spacecraft speed of 9.8 km/s corresponds to an energy of 8 eV. c) Quadrupole analyzer: Tuning on the peak and mass resolution are separately commandable with 4 different values. Mass peak desired can be programmed as 8 selectable mass numbers, a unit amu sweep, and 1/8 amu sweep. The latter is primarily an engineering tool to check tuning and resolution. The unit sweep is a species survey mode, and programmed mass mode is used to concentrate on high time resolution measurements of particular species. d) Secondary electron multiplier detector: There are 4 selectable gain values determined from four commandable high voltage levels. e) Pulse counter discriminator: There are 4 commandable discriminator levels used in counting the individual multiplier pulses. A commandable mode is available to alternately read out pulse counter and electrometer values for multiplier gain measurements. REFERENCES Niemann, H.B., J.R. Booth, J.E. Cooley, R.E. Hartle, W.T. Kasprzak, N.W. Spencer, S.H. Way, D.M. Hunten, G.R.Carignan, Pioneer Venus Orbiter Neutral Mass Spectrometer Experiment, IEEE Trans. Geo. Rem. Sens., _GE-18_, 60-65, 1980." /* */ /******************************************************************************/ /* */ SCIENTIFIC_OBJECTIVES_SUMMARY = " The prime mission of the Orbiter Neutral Mass Spectrometer (ONMS) is to perform in-situ measurements of the neutral gas composition and its variation with altitude and local solar time in the thermosphere and exosphere of Venus. Measurements of these variations are important in defining the dynamical, chemical and thermal state of the upper atmosphere. When the periapsis altitude is below about 250 km, the neutral densities of helium, atomic oxygen, atomic nitrogen, molecular nitrogen, carbon monoxide and carbon dioxide are measured. Gas kinetic temperatures can be derived from an analysis of the density scale heights. Wave-like perturbations consistent with gravity waves can be observed after removal of the altitude variation in the data. Neutral density data were taken during orbit 1-645 and during orbits 4954-5055. Superthermal ions with energy > 36 eV in the spacecraft reference have also been detected. Ions of this energy have sufficient energy to escape the planet and represent an atmospheric loss. They have been observed in the near tail region and near the dayside ionopause. The ions were first detected in orbits associated with measurements of the neutral density and are evidenced as erratic signals above the usual gas background signal at high altitudes. The ions must have an energy exceeding the voltage on the ion repeller grid (36 V) in order to be detected. The ion composition can be determined and consists of mainly O+ with traces of He+, N+, CO+ and/or N2+, NO+ and O2+. CO2+ occurs very rarely. H+ is not measurable with the current instrument configuration. After the first 935 orbits, when the altitude of periapsis was above 300 km and the neutral atmosphere could no longer be measured, the instrument was configured to perform measurements of the superthermal ions with the filament off and ion repeller at 36 V. The direction of the ion flow in the ecliptic plane can also be determined from the spin modulation of the data. Thermal ions can also be measured with the filament off and the ion repeller set at 0 V. Species observed include He+, N+, O+, CO+ and/or N2+, NO+, O2+ and CO2+. H+ is not measurable with the current instrument configuration. One component of the ion drift in the ecliptic plane can also be determined. Thermal ion measurements have been taken sporadically at the end of neutral density passes and on alternate orbits when superthermal ions are not being measured. The ONMS instrument was not operated on all orbits and some orbits are devoted to engineering studies. Typically neutral density passes occupied -40 min. to +30 min. relative to the time of periapsis. Ion and superthermal ion mode passes typically are 15 to 20 minutes in duration on either side of periapsis. Neutral density passes during entry also took about this same amount of time." /* */ /******************************************************************************/ /* */ INSTRUMENT_CALIBRATION_DESC = " Initial testing of the retarding and ion modes was done using a low energy, 0-25 eV, ion beam. Gas calibrations to establish the closed source neutral density were performed over the pressure ranges expected in flight. This calibration established the overall relation between the thermalized particle density in the ionizing region and the electronics telemetry output. Gases used for calibration were CO2, N2, O2, Ar, He, CO and NO. The calibrations established mass spectral cracking patterns, low and high electron energy sensitivities, pulse counter dead time correction, ratio of electron multiplier count rate and current output, tuning and mass resolution characteristics. Comparison of the ONMS neutral densities with mass density measurements near 100 km deduced from the Pioneer Venus lower atmosphere probes, the bus mass spectrometer measurements and orbiter drag indicate that the overall sensitivity is about a factor of 1.6 low (Hedin et al., 1983). Estimates of the gas flow into the ion source at satellite speeds indicate that the sensitivity may deviate from that assumed in the data reduction. Laboratory tests of the prototype instrument in a molecular beam system produced results consistent with this hypothesis but not conclusive because of the limited range of speeds that could be obtained. The relationship between the superthermal ion flux and instrument output was established in a post-flight calibration of the flight backup unit. In the energy range 40-200 V, the maximum transmission occurs 10 V above the ion repeller potential and drops to 15% of the maximum transmission value above 100 eV. The transmission decreases with increasing mass number and for Ar+ ions (m/e=40) it is about a factor of 2.5 below that for O+ at the maximum transmission point. The relationship between thermal ion density and instrument output was established by direct comparison of the O+ signal with the O+ density determined from the Orbiter Ion Mass Spectrometer (OIMS) instrument using O+ data from orbit number 530 at 300 seconds from periapsis. Other species are assumed to have the same sensitivity as that of O+. In this mode superthermal ions cannot be distinguished from thermal ions. Stability of the electronics and sensor combination as a function of temperature was established in tests using a vacuum chamber with temperature control." /* */ /******************************************************************************/ /* */ OPERATIONAL_CONSID_DESC = " Instrument commanding: cannot directly command filament A to B; must turn-off filament between A and B cannot use highest multiplier voltage; current levels too high cannot use spin segment mode in PERB format and bit rates exceeding 1024 bps; 4K memory overflow; cannot use it when less than one housekeeping cycle is stored in memory Maximum signal limitations: filament is shut off if detector multiplier current exceeds 15 ua " END_OBJECT = INSTINFO /* */ /******************************************************************************/ /* Template: Instrument Detector Template Rev: 19890121 */ /* Note: This template shall be repeated for each */ /* detector utilized by an instrument. */ OBJECT = INSTDETECT DETECTOR_ID = MASS_SPECTROMETER DETECTOR_TYPE = QUADRUPOLE_MASS_SPEC DETECTOR_ASPECT_RATIO = "N/A" MINIMUM_WAVELENGTH = "N/A" MAXIMUM_WAVELENGTH = "N/A" NOMINAL_OPERATING_TEMPERATURE = 273 /**/ DETECTOR_DESC = " The ONMS instrument is a quadrupole mass spectrometer with an electron impact ion source for measurement of neutral gas composition in the mass range 1 to 46 amu. The sensor consists of an ion source, a quadrupole mass filter and secondary electron multiplier as an ion detector. The ion source is partially enclosed and exposed to the ambient atmosphere of neutral and ion particles through an entrance aperture. Just inside the aperture is the ion repeller grid at 36 V above spacecraft ground designed to reject ions of this energy or less. On either side of the ion repeller grid is a grid at -4.3 V designed to reject low energy electrons. Neutral gas particles are not influenced by these grid potentials. They pass through to the ionization region where a small fraction are ionized by electron impact from an electrostatically focused electron beam generated by a hot filament. The ions are then focused into the quadrupole analyzer for separation according to mass to charge ratio. The ion source grid assembly can also function as a retarding potential analyzer (RPA) for analysis of direct streaming particles that have not had any surface collisions. With the filament off and the ion repeller set to 0 V, the sensor can detect thermal ions. With the ion repeller set to 36 V, superthermal ions exceeding this energy can be detected." SENSITIVITY_DESC = " Detection ranges{(1)}: Neutral composition: N2 sensitivity: 5.E4 particles/cm**3 / (count/sec) Open source density range: 3.E5 to 4E.12 particles/cm**3 for N2 Closed source density range: 5.E3 to 7.E10 particles/cm**3 for N2 Superthermal (>36 eV) ions: O+ sensitivity: 4.E3 (particles/cm**2/sec)/(count/sec) O+ flux range for 40 eV ions: 2.E4 to 3.E11 particles/cm**2/sec O+ density range for 40 eV ions: 0.01 to 1.E5 particles/cm**3 Thermal ions: O+ sensitivity: 0.02 (particles/cm**3)/(counts/sec), normalized to OIMS O+ density range: 0.02 to 2.6E5 particles/cm**3 for a spacecraft speed of 9.6 km/s {(1)} Based on minimum count rate, detector dynamic range and instrument sensitivity for mode used" END_OBJECT = INSTDETECT /******************************************************************************/ /* Template: Instrument Electronics Template Rev: 19890121 */ /* Note: This template shall be repeated for each */ /* electronics id description utilized by an */ /* instrument. */ OBJECT = INSTELEC ELECTRONICS_ID = NMS_ELECTRONICS ELECTRONICS_DESC = " Data accumulation is always done at equally spaced time intervals. Each 16 bit telemetry represents one reading obtained over an integration time determined by the spacecraft bit rate and format. The individual 8 bit telemetry words assigned to the ONMS in a minor frame are not equally spaced in time. Therefore, the data has to be stored internally for a period of time and then sent to the telemetry. The storage and readout are accomplished through the use of two memories. One memory is reading out unequally spaced data to the spacecraft telemetry system while the other is accumulating equally spaced data from the instrument. Both memories are first in, first out (FIFO) type and are switched simultaneously. The time interval over which the ONMS data is accumulated in memory depends on the spacecraft bit rate, format, and spin segment status. With no spin segment, the memories are switched on at a minor frame beginning, data is accumulated for one minor frame and then read out to the telemetry system during the next minor frame. With spin segment mode commanded, the data is accumulated at four times the rate of the no spin segment mode and at equally spaced time intervals from -45{o} to +45{o} roll angle relative to the ONMS velocity ram direction. The memory switch time and data accumulation start time are determined from the spacecraft RAM pulse, which is assumed to represent the maximum velocity ram for the spacecraft +X axis (0{o} spacecraft azimuth angle), and the ONMS azimuth angle. The ONMS has telemetry words in the formats PERC (6 words), PERB (14 words), and APOB (2 words). Each word consists of 8 bits. The length of the data cycle for housekeeping data is 128 words. The unit of 64 16-bit words contains all of the information to determine the current command status, monitor values, etc., and is the basic unit of processing for the data. In addition to the internal monitors read out by the instrument electronics, other monitors are available from the spacecraft telemetry which do not require the ONMS to be operating: instrument temperature, bus voltage and instrument on/off status. Number of words in telemetry format per minor frame: PERB: 14 8-bit words PERC: 6 8-bit words APOB: 2 8-bit words 1 minor frame = 64*8 bits" END_OBJECT = INSTELEC /******************************************************************************/ /* Template: Instrument Filter Template Rev: 19890121 */ /* Note: This template shall be repeated for each */ /* filter utilized by an instrument. */ OBJECT = INSTFILTER FILTER_NUMBER = "N/A" FILTER_NAME = "N/A" FILTER_TYPE = "N/A" MINIMUM_WAVELENGTH = "N/A" CENTER_FILTER_WAVELENGTH = "N/A" MAXIMUM_WAVELENGTH = "N/A" MEASUREMENT_WAVE_CALBRT_DESC = "N/A" END_OBJECT = INSTFILTER /* Template: Instrument Optics Template Rev: 19890121 */ /* Note: This template shall be completed for each */ /* optical instrument. */ OBJECT = INSTOPTICS TELESCOPE_ID = "N/A" TELESCOPE_FOCAL_LENGTH = "N/A" TELESCOPE_DIAMETER = "N/A" TELESCOPE_F_NUMBER = "N/A" TELESCOPE_RESOLUTION = "N/A" TELESCOPE_TRANSMITTANCE = "N/A" TELESCOPE_T_NUMBER = "N/A" TELESCOPE_T_NUMBER_ERROR = "N/A" TELESCOPE_SERIAL_NUMBER = "N/A" OPTICS_DESC = "N/A" END_OBJECT = INSTOPTICS /******************************************************************************/ /* Template: Spacecraft Instrument Offset Template Rev: 19890121 */ /* Note: This template shall be completed for each */ /* platform used for instrument positioning. */ OBJECT = SCINSTOFFSET PLATFORM_OR_MOUNTING_NAME = "SPACECRAFT BUS" CONE_OFFSET_ANGLE = 26.6 CROSS_CONE_OFFSET_ANGLE = "N/A" TWIST_OFFSET_ANGLE = "N/A" /* 321.17 */ INSTRUMENT_MOUNTING_DESC = " Mounting angles for the normal perpendicular to instrument orifice: Azimuth angle relative to spacecraft X-axis: 321.17 degrees Zenith angle relative to spacecraft Z-axis (spin axis): 26.6 DEG" END_OBJECT = SCINSTOFFSET /******************************************************************************/ /* Template: Instrument Section Template Rev: 19890121 */ /* Note: This template group shall be repeated for each */ /* instrument section. */ OBJECT = INSTSECTION SECTION_ID = NMS /* Template: Instrument Section Information Template Rev: 19890121 */ /* Note: This section shall be completed for each */ /* instrument section id entered in the instsection */ /* template. */ OBJECT = INSTSECTINFO SCAN_MODE_ID = "N/A" DATA_RATE = "N/A" SAMPLE_BITS = 16 TOTAL_FOVS = "N/A" /* Template: Instrument Section Fields Of View Template Rev: 19890121 */ /* Note: This template shall be repeated for each */ /* instrument section fields of view. */ OBJECT = INSTSECTFOVS FOV_SHAPE_NAME = "N/A" HORIZONTAL_PIXEL_FOV = "N/A" VERTICAL_PIXEL_FOV = "N/A" HORIZONTAL_FOV = "N/A" VERTICAL_FOV = "N/A" FOVS = 1 END_OBJECT = INSTSECTFOVS END_OBJECT = INSTSECTINFO /* Template: Instrument Section Parameter Template Rev: 19890121 */ /* Note: This template shall be repeated for each */ /* instrument section parameter. */ OBJECT = INSTSECTPARM INSTRUMENT_PARAMETER_NAME = NEUTRAL_DENSITY MINIMUM_INSTRUMENT_PARAMETER = 5.0E3 /**/ MAXIMUM_INSTRUMENT_PARAMETER = 7.0E10 /**/ NOISE_LEVEL = UNK INSTRUMENT_PARAMETER_UNIT = "CM**-3" SAMPLING_PARAMETER_NAME = TIME MINIMUM_SAMPLING_PARAMETER = 0.006 MAXIMUM_SAMPLING_PARAMETER = 0.171875 SAMPLING_PARAMETER_INTERVAL = "N/A" SAMPLING_PARAMETER_RESOLUTION = "N/A" SAMPLING_PARAMETER_UNIT = SECONDS END_OBJECT = INSTSECTPARM /******************************************************************************/ OBJECT = INSTSECTPARM INSTRUMENT_PARAMETER_NAME = THERMAL_ION_DENSITY MINIMUM_INSTRUMENT_PARAMETER = 2.0E-2 /* */ MAXIMUM_INSTRUMENT_PARAMETER = 2.6E5 /* */ NOISE_LEVEL = UNK INSTRUMENT_PARAMETER_UNIT = "CM**-3" SAMPLING_PARAMETER_NAME = TIME MINIMUM_SAMPLING_PARAMETER = 0.006 MAXIMUM_SAMPLING_PARAMETER = 0.171875 SAMPLING_PARAMETER_INTERVAL = "N/A" SAMPLING_PARAMETER_RESOLUTION = "N/A" SAMPLING_PARAMETER_UNIT = SECONDS END_OBJECT = INSTSECTPARM /******************************************************************************/ OBJECT = INSTSECTPARM INSTRUMENT_PARAMETER_NAME = SUPERTHERMAL_ION_FLUX MINIMUM_INSTRUMENT_PARAMETER = 2.0E4 /* */ MAXIMUM_INSTRUMENT_PARAMETER = 3.0E11 /* */ NOISE_LEVEL = UNK INSTRUMENT_PARAMETER_UNIT = "CM**(-3)SECOND**(-1)" SAMPLING_PARAMETER_NAME = TIME MINIMUM_SAMPLING_PARAMETER = 0.006 MAXIMUM_SAMPLING_PARAMETER = 0.171875 SAMPLING_PARAMETER_INTERVAL = "N/A" SAMPLING_PARAMETER_RESOLUTION = "N/A" SAMPLING_PARAMETER_UNIT = SECONDS END_OBJECT = INSTSECTPARM /* Template: Instrument Section Detector Template Rev: 19890121 */ /* Note: This template shall be repeated for each */ /* instrument section detector id. */ OBJECT = INSTSECTDET DETECTOR_ID = NMS END_OBJECT = INSTSECTDET /* Template: Instrument Section Electronics Template Rev: 19890121 */ /* Note: This template shall be repeated for each */ /* instrument section electronics component. */ OBJECT = INSTSECTELEC ELECTRONICS_ID = NMS_ELECTRONICS END_OBJECT = INSTSECTELEC /* Template: Instrument Section Filter Template Rev: 19890121 */ /* Note: This template shall be repeated for each */ /* instrument section filter. */ OBJECT = INSTSECTFILT FILTER_NUMBER = "N/A" END_OBJECT = INSTSECTFILT /* Template: Instrument Section Optics Template Rev: 19890121 */ /* Note: This template shall be repeated for each */ /* instrument section telescope. */ OBJECT = INSTSECTOPTC TELESCOPE_ID = "N/A" END_OBJECT = INSTSECTOPTC END_OBJECT = INSTSECTION /******************************************************************************/ /* Template: Instrument Mode Information Template Rev: 19890121 */ /* Note: This template shall be repeated for each */ /* instrument mode. */ OBJECT = INSTMODEINFO INSTRUMENT_MODE_ID = "NEUTRAL_DENSITY (ND)" GAIN_MODE_ID = "N/A" DATA_PATH_TYPE = MEMORY_READOUT INSTRUMENT_POWER_CONSUMPTION = 12 INSTRUMENT_MODE_DESC = " Currently there are three distinct types of data that can be acquired by the ONMS instrument: Neutral density, superthermal ion flux and thermal ion density. Independent of these three data types, there are a number of modes in which the data can be taken as well as a number of modes in which the instrument can be configured and tuned. Generally speaking these different modes correspond to different command configurations of the instrument. Data measurement types: Neutral gas composition: closed source open source with particle retarding Ion composition: superthermal ions > 36 eV relative to spacecraft ground (ion repeller set to 36 V) normal ions > 0 V relative to spacecraft ground (ion repeller set to 0 V) Detection ranges{(1)}: Neutral composition: N2 sensitivity: 5.E4 particles/cm**3 / (count/sec) Open source density range: 3.E5 to 4E.12 particles/cm**3 for N2 Closed source density range: 5.E3 to 7.E10 particles/cm**3 for N2 {(1)} Based on minimum count rate, detector dynamic range and instrument sensitivity for mode used The instrument configuration modes: a) Ion source: Two different electron energies can be selected by command. Ions can also be measured with the filament off. An ion repeller grid just inside the entrance aperture at 36 V or 0 V rejects positive ions of this energy or less. Neutral gas particles are not affected by the 36 V grid potential and pass through into the ionization region. b) Retarding potential analyzer: Retarding and non-retarding modes can be commanded separately along with a mode in which they alternate. A retarding potential sweep through a range of retarding voltages is also commandable and is considered an engineering diagnostic tool. The retarding voltage is VR=O+G*M where the offset O and and the gain G each have 4 separate commandable levels, and M is the mass number in amu. The retarding sweep voltage is VR=O+0.0103*(64-S) where D is a fixed value and S is number 1...64. For reference a spacecraft speed of 9.8 km/s corresponds to an energy of 8 eV. c) Quadrupole analyzer: Tuning on the peak and mass resolution are separately commandable with 4 different values. Mass peak desired can be programmed as 8 selectable mass numbers, a unit amu sweep, and 1/8 amu sweep. The latter is primarily an engineering tool to check tuning and resolution. The unit sweep is a species survey mode, and programmed mass mode is used to concentrate on high time resolution measurements of particular species. d) Secondary electron multiplier detector: There are 4 selectable gain values determined from four commandable high voltage levels. e) Pulse counter discriminator: There are 4 commandable discriminator levels used in counting the individual multiplier pulses. A commandable mode is available to alternately read out pulse counter and electrometer values for multiplier gain measurements." /* Template: Instrument Mode Section Information Template Rev: 19890121 */ /* Note: This template shall be repeated for each association of an */ /* instrument mode to an instrument section. */ OBJECT = INSTMODESECT SECTION_ID = NMS END_OBJECT = INSTMODESECT END_OBJECT = INSTMODEINFO OBJECT = INSTMODEINFO INSTRUMENT_MODE_ID = "SUPERTHERMAL IONS" GAIN_MODE_ID = "N/A" DATA_PATH_TYPE = MEMORY_READOUT INSTRUMENT_POWER_CONSUMPTION = 12 /* */ INSTRUMENT_MODE_DESC = " Currently there are three distinct types of data that can be acquired by the ONMS instrument: Neutral density, superthermal ion flux and thermal ion density. Independent of these three data types, there are a number of modes in which the data can be taken as well as a number of modes in which the instrument can be configured and tuned. Generally speaking these different modes correspond to different command configurations of the instrument. Data measurement types: Neutral gas composition: closed source open source with particle retarding Ion composition: superthermal ions > 36 eV relative to spacecraft ground (ion repeller set to 36 V) normal ions > 0 V relative to spacecraft ground (ion repeller set to 0 V) Detection ranges{(1)}: Superthermal (>36 eV) ions: O+ sensitivity: 4.E3 (particles/cm**2/sec)/(count/sec) O+ flux range for 40 eV ions: 2.E4 to 3.E11 particles/cm**2/sec O+ density range for 40 eV ions: 0.01 to 1.E5 particles/cm**3 {(1)} Based on minimum count rate, detector dynamic range and instrument sensitivity for mode used The instrument configuration modes: a) Ion source: Two different electron energies can be selected by command. Ions can also be measured with the filament off. An ion repeller grid just inside the entrance aperture at 36 V or 0 V rejects positive ions of this energy or less. Neutral gas particles are not affected by the 36 V grid potential and pass through into the ionization region. b) Retarding potential analyzer: Retarding and non-retarding modes can be commanded separately along with a mode in which they alternate. A retarding potential sweep through a range of retarding voltages is also commandable and is considered an engineering diagnostic tool. The retarding voltage is VR=O+G*M where the offset O and and the gain G each have 4 separate commandable levels, and M is the mass number in amu. The retarding sweep voltage is VR=O+0.0103*(64-S) where D is a fixed value and S is number 1...64. For reference a spacecraft speed of 9.8 km/s corresponds to an energy of 8 eV. c) Quadrupole analyzer: Tuning on the peak and mass resolution are separately commandable with 4 different values. Mass peak desired can be programmed as 8 selectable mass numbers, a unit amu sweep, and 1/8 amu sweep. The latter is primarily an engineering tool to check tuning and resolution. The unit sweep is a species survey mode, and programmed mass mode is used to concentrate on high time resolution measurements of particular species. d) Secondary electron multiplier detector: There are 4 selectable gain values determined from four commandable high voltage levels. e) Pulse counter discriminator: There are 4 commandable discriminator levels used in counting the individual multiplier pulses. A commandable mode is available to alternately read out pulse counter and electrometer values for multiplier gain measurements." /* Template: Instrument Mode Section Information Template Rev: 19890121 */ /* Note: This template shall be repeated for each association of an */ /* instrument mode to an instrument section. */ OBJECT = INSTMODESECT SECTION_ID = NMS END_OBJECT = INSTMODESECT END_OBJECT = INSTMODEINFO OBJECT = INSTMODEINFO INSTRUMENT_MODE_ID = "THERMAL IONS" GAIN_MODE_ID = "N/A" DATA_PATH_TYPE = MEMORY_READOUT INSTRUMENT_POWER_CONSUMPTION = 12 /* */ INSTRUMENT_MODE_DESC = " Currently there are three distinct types of data that can be acquired by the ONMS instrument: Neutral density, superthermal ion flux and thermal ion density. Independent of these three data types, there are a number of modes in which the data can be taken as well as a number of modes in which the instrument can be configured and tuned. Generally speaking these different modes correspond to different command configurations of the instrument. Data measurement types: Neutral gas composition: closed source open source with particle retarding Ion composition: superthermal ions > 36 eV relative to spacecraft ground (ion repeller set to 36 V) normal ions > 0 V relative to spacecraft ground (ion repeller set to 0 V) Detection ranges{(1)}: Thermal ions: O+ sensitivity: 0.02 (particles/cm**3)/(counts/sec), normalized to OIMS O+ density range: 0.02 to 2.6E5 particles/cm**3 for a spacecraft speed of 9.6 km/s {(1)} Based on minimum count rate, detector dynamic range and instrument sensitivity for mode used The instrument configuration modes: a) Ion source: Two different electron energies can be selected by command. Ions can also be measured with the filament off. An ion repeller grid just inside the entrance aperture at 36 V or 0 V rejects positive ions of this energy or less. Neutral gas particles are not affected by the 36 V grid potential and pass through into the ionization region. b) Retarding potential analyzer: Retarding and non-retarding modes can be commanded separately along with a mode in which they alternate. A retarding potential sweep through a range of retarding voltages is also commandable and is considered an engineering diagnostic tool. The retarding voltage is VR=O+G*M where the offset O and and the gain G each have 4 separate commandable levels, and M is the mass number in amu. The retarding sweep voltage is VR=O+0.0103*(64-S) where D is a fixed value and S is number 1...64. For reference a spacecraft speed of 9.8 km/s corresponds to an energy of 8 eV. c) Quadrupole analyzer: Tuning on the peak and mass resolution are separately commandable with 4 different values. Mass peak desired can be programmed as 8 selectable mass numbers, a unit amu sweep, and 1/8 amu sweep. The latter is primarily an engineering tool to check tuning and resolution. The unit sweep is a species survey mode, and programmed mass mode is used to concentrate on high time resolution measurements of particular species. d) Secondary electron multiplier detector: There are 4 selectable gain values determined from four commandable high voltage levels. e) Pulse counter discriminator: There are 4 commandable discriminator levels used in counting the individual multiplier pulses. A commandable mode is available to alternately read out pulse counter and electrometer values for multiplier gain measurements." /* Template: Instrument Mode Section Information Template Rev: 19890121 */ /* Note: This template shall be repeated for each association of an */ /* instrument mode to an instrument section. */ OBJECT = INSTMODESECT SECTION_ID = NMS END_OBJECT = INSTMODESECT END_OBJECT = INSTMODEINFO /******************************************************************************/ /* Template: Instrument Reference Information Template Rev: 19890121 */ /* Note: The following template form part of a standard */ /* set for the submission of a publication reference */ /* to the PDS. */ OBJECT = INSTREFINFO REFERENCE_KEY_ID = NIEMANNETAL1983 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = SPECTROSCOPY JOURNAL_NAME = "ADVANCES INS SPACE RESEARCH" PUBLICATION_DATE = 1983 REFERENCE_DESC = " Niemann, H.B. and W.T. Kasprzak, Comparative Neutral Composition Instrumentation and New Results, Advances in Space Research,261-270, 1983." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H.B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = INSTREFINFO OBJECT = INSTREFINFO REFERENCE_KEY_ID = NIEMANNETAL1979A OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = SPECTROSCOPY JOURNAL_NAME = "IEEE TRAN. GEOPHYSICAL REMOTE SENSING" PUBLICATION_DATE = 1979-04 REFERENCE_DESC = " Niemann, H.B., J.R. Booth, J.E. Cooley, R.E. Hartle, W.TY. Kasprzak, N.W. Spencer, S.H. Way, D.M. Hunten, G.R. Carignan, 'Pioneer Venus Orbiter Neutral Mass Spectrometer Experiment', IEEE Trans. Geo. Rem. Sens., GE-18, 60-65, 1980." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H.B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = INSTREFINFO END_OBJECT = SCINSTRUMENT /****************** NEUTRAL LOW RES Dataset Template **************************/ /* Modifications: */ /* 930414 -- EFRIED * /* updated Data Set templates according to new std. */ /* Data Set Template -> Spacecraft Data Set Template */ /* event_start_time, event_stop_time -> start_time, stop_time */ /* */ /* Template: Spacecraft Data Set Template Rev: 19890121 */ /* */ /* Note: The following templates form part of a standard set */ /* for the submission of a single dataset to the PDS. */ /* */ /* Hierarchy: SCDATASET */ /* DATASETINFO */ /* DATASETTARG */ /* DSPARMINFO */ /* SCDSHOST */ /* DSREFINFO */ /* REFERENCE */ /* REFAUTHORS */ OBJECT = SCDATASET DATA_SET_ID = "PVO-V-ONMS-4-NEUTRALDENSITY-12SEC-V1.0" OBJECT = DATASETINFO DATA_SET_NAME = "PVO VENUS ONMS BROWSE NEUTRAL DENSITY 12 SECOND V1.0" DATA_SET_COLLECTION_MEMBER_FLG = N START_TIME = 1978-12-07T14:30:47.000Z STOP_TIME = 1992-10-07T19:49:39.752Z NATIVE_START_TIME = UNK NATIVE_STOP_TIME = UNK DATA_OBJECT_TYPE = "TIME SERIES" DATA_SET_RELEASE_DATE = 1993-03-31 PROCESSING_LEVEL_ID = 4 PRODUCER_FULL_NAME = "DR. WAYNE KASPRZAK" PRODUCER_INSTITUTION_NAME = "GODDARD SPACE FLIGHT CENTER" SOFTWARE_FLAG = Y DETAILED_CATALOG_FLAG = N PROCESSING_START_TIME = UNK PROCESSING_STOP_TIME = UNK DATA_SET_DESC =" orbits time 3 1978-12-07T14:30:47.000Z 640 1980-09-05T17:14:34.016Z 4961 1992-07-06T00:26:53.847Z 5055 1992-10-07T19:49:39.752Z The instrument was designed to determine the composition of the neutral thermosphere/exosphere of Venus. The term composition includes both the type of neutral gases present and their quantitative amount. The measurements begin at the orbit's periapsis altitude and extend to a limiting altitude at which the ambient signal becomes comparable to the gas background and/or detector measurement threshold. The neutral composition includes helium, atomic nitrogen, atomic oxygen, molecular nitrogen, carbon monoxide and carbon dioxide. The data reduction has been described in Niemann et al. (1980a) and Kasprzak et al. (1980). The source of the data and their corrections are summarized below: SPECIES M/E USED COMMENTS He 4 N 30 Surface recombined N and O O 32 Surface recombined O to O2; corrected for CO2 fragmentation corrected for estimated surface recombination of O to CO2(*) N2,CO 14,28 m/e 14 corrected for NO, CO and CO2 fragmentation; m/e 28 corrected for CO2 fragmentation CO2 44 Corrected for surface recombination of O to CO2* (*) the correction is based on matching scale height temperatures of O and CO2. The data are from the nonretarding potential mode of the instrument. Data from the retarding mode are consistent with those obtained from the nonretarding mode and have not been included. The data set does not include the factor of 1.6 increase in density needed to maintain compatibility with other data sets as discussed by Hedin et al. (1983). Two data sets are provided: high resolution (HIRES), every point, composition; and low resolution (LORES), 12 second sampled, composition. The LORES data set represents the best estimated composition data and is derived from the HIRES data set. The field names described in RECORD 1: NAME DESCRIPTION UNITS YYYY YYYY=4 digit year DDD DDD=3 digit day of year UT Universal Time represented as the number of milliseconds since 1966-01-01T00:00:00Z stored as a double precision floating point number. ORBIT Orbit number TIMTAG Nominal time tag assigned by project DHE Number density of He part/cm**3 DN Number density of N part/cm**3 DO Number density of O part/cm**3 DN2 Number density of N2 part/cm**3 DCO Number density of CO part/cm**3 DCO2 Number density of CO2 part/cm**3 DRHO Total mass density g/cm**3 DTOT Total number density part/cm**3 This data is a representative sample, approximately once per 12 seconds, of the high resolution data. It is constructed at designated times which have been supplied by the Project. Data with errors greater that 30% are not included nor are data with angles of attack greater than 40 degrees. An absolute altitude cutoff of 250 km was used for all species except for He for which 350 km was used. Each representative data point is constructed using an exponentially weighted average of the data over a 24 second interval centered at the sample point time. Corrections to the number densities of CO2 and O for surface reactions were made at this time based on empirical model results. A minimum of 3 data points per species and all data available for corrections are required to be present in order for a sample point to be output. The total number density and total mass density are computed if all major species (CO2, CO, N2, and O) are present. The data spacing is nominally 12 seconds except for the -12, 0, 12 time tags. Although time tags from -1800 to 1800 seconds are generated, only those data records for which at least one species has a valid value for that time tag are output. No spacecraft positional parameters have been included in the data sets. These can be obtained from the SEDR data submitted separately by the Project." /* */ /******************************************************************************/ /* */ CONFIDENCE_LEVEL_NOTE = " Several criteria were invoked when inserting data for a given orbit: orbit and attitude parameters must exist (project supplied); the spacecraft format and bit rate must be appropriate for acquisition of data by the ONMS; and the command sequence for the instrument must be appropriate for useful determination of atmospheric composition. Cases where useful composition cannot be determined include special test modes (e.g., retarding potential sweeps, filament off) and 1/8 unit amu sweep modes. In addition, composition for the LORES data set cannot be easily determined for unit amu sweep mode. The ONMS was not operational for every orbit nor is every orbit complete due to data gaps introduced by use of telemetry formats for which the ONMS has no instrument output. Useful composition data are gathered from the lowest periapsis altitude to a maximum altitude generally around 250 km (about 300 km for He). The actual maximum altitude depends on the accumulated surface gas buildup acquired from previous orbits which creates a gas background. The gas background was estimated from high altitude averages of the data and for all species, except helium, an inbound signal/background ratio of 2 and an outbound signal/background ratio of 4 were used as cutoff values. In some cases superthermal ions (e.g., Kasprzak et al.,1982) were observed at low altitudes (e.g., below 300 km for orbit 219) and these were removed when visually detected. Some problems have been observed in the high altitude data very near cutoff, particularly for outbound N2. Several data points were never removed and appear higher than the expected extrapolation of the data to that time. Residual spin modulation which had not been completely removed is evident in the processed data. The source of the spin residuals are the gas/surface adsorption/desorption effects which were not removed from the data and a noncosine behavior for the response of the ion source density with angle of attack. Another feature observed occasionally at large angles of attack (>40 degrees) is a reduction of the data when compared to data at lower angles of attack. This has been determined to be due to antenna shadowing; that is, the ONMS geometric view cone 'sees' the spacecraft antenna at extreme angles of attack. Occasionally near minimum angle of attack (<10 degrees), enhanced data points are observed for m/e=4 (He channel) which are apparently high energy ions/neutrals traveling along the tube axis and being detected. The more extreme points in either of these two cases have been mass flagged. The data time spacing depends on the spacecraft bit rate and format, and the particular instrument commands executed. Usually programmed mass format was used but occasionally unit amu and 1/8 amu sweeps were implemented. Several orbits switched from low electron energy to high electron energy and as a result there may be a discontinuity at the transition point. The 1/8 amu sweep data have not been included. Atomic nitrogen was measured in programmed mass mode only after orbit 190. Orbits 1-19 generally do not have reliable relative composition due to the fact that gas-surface processes in the ion source had not stabilized. This affects all surface reactive species except He. Isolated (one or two points per several spin cycles) high resolution data points are occasionally observed and they should be regarded as erroneous points which are more likely wrong than right. The error associated with the points is more an indication of data quality than of absolute uncertainty. It contains the statistical error of the data determined for the principle m/e used for the species from the detector signal plus the errors coming from any other species used to correct the data. It also contains a contribution which is proportional to the background/signal ratio. The total relative error is at least an additional 5-10% above this value." END_OBJECT = DATASETINFO /* */ /******************************************************************************/ /* */ OBJECT = DATASETTARG TARGET_NAME = VENUS END_OBJECT = DATASETTARG OBJECT = DSPARMINFO SAMPLING_PARAMETER_NAME = TIME SAMPLING_PARAMETER_RESOLUTION = 12.0 MINIMUM_SAMPLING_PARAMETER = "N/A" MAXIMUM_SAMPLING_PARAMETER = "N/A" SAMPLING_PARAMETER_INTERVAL = 12.0 MINIMUM_AVAILABLE_SAMPLING_INT = 0.25 SAMPLING_PARAMETER_UNIT = SECOND DATA_SET_PARAMETER_NAME = "NEUTRAL DENSITY" NOISE_LEVEL = UNK DATA_SET_PARAMETER_UNIT = "PARTICLES/CM**3" END_OBJECT = DSPARMINFO OBJECT = SCDSHOST INSTRUMENT_HOST_ID = PVO INSTRUMENT_ID = ONMS END_OBJECT = SCDSHOST /* */ /******************************************************************************/ /* */ OBJECT = DSREFINFO REFERENCE_KEY_ID = BRINTON1980 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "UNK" JOURNAL_NAME = "GEOPHYSICAL RESEARCH LETTERS" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Brinton, H.C., H.A. Taylor, H.B. Niemann, H.G. Mayr, A.F. Nagy,T.E.Cravens, and D.F. Strobel, Venus Nighttime Hydrogen Bulge, Geophysical research Letters, 7, 865-868, 1980.", OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. C. BRINTON" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = HEDINETAL1983 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1983 REFERENCE_DESC = " Hedin, A.E., H.B. Niemann, W.T. Kasprzak and A. Seiff, Global Empirical Model of the Venus Thermosphere, Journal of Geophysical Research, vol. 88, 73-83, 1983." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. SEIFF" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = "HOEGYETAL1990" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1990 REFERENCE_DESC = " Hoegy, W.R., L.H. Brace, W.T. Kasprzak and C.T. Russell, Small-Scale Plasma, Magnetic, and Neutral Density Fluctuations in the Nightside of Venus Ionosphere, Journal of Geophysical Research, vol. 95, 4085-4102, 1990. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WALTER R. HOEGY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LARRY H. BRACE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "CHRISTOPHER T. RUSSELL" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KARETAL1991 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1990 REFERENCE_DESC = " Kar, J., R. Paul, R. Kohli, K.K. Mahajan, W.T. Kasprzak and H.B. Niemann, On the Response of Exospheric Temperature on Venus to Solar Wind Conditions, Journal of Geophysical Research, 96,7901-7904,1991." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. KAR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. PAUL" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. KOHLI" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "K. K. MAHAJAN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1980 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = "Geophysical Research Letters" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Kasprzak, W.T., A.E. Hedin, H.B. Niemann and N.W. Spencer, Atomic Nitrogen in the Upper Atmosphere of Venus, Geophysical Research Letters, vol. 7,106-108, 1980. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N. W. SPENCER" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1993A OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "UNK" JOURNAL_NAME = "GEOPHYSICAL RESEARCH LETTERS" PUBLICATION_DATE = 1993 REFERENCE_DESC = " Kasprzak, W.T., H.B. Niemann, A.E. Hedin and S.W. Bougher, Wave-like Perturbations Observed at Low Altitudes by the Pioneer Venus Orbiter Neutral Mass Spectrometer During Entry, Geophys. Res. Lett., 20, 2755-2758, 1993." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "S. W. BOUGHER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1993B OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS COMPOSITION" JOURNAL_NAME = "GEOPHYSICAL RESEARCH LETTERS" PUBLICATION_DATE = 1993 REFERENCE_DESC = " Kasprzak, W.T., H.B. Niemann, A.E. Hedin, S.W. Bougher and D.M. Hunten, Neutral Composition Measurements by the Pioneer Venus Neutral Mass Spectrometer During Orbiter Entry, Geophys. Res. Lett., 20, 2747-2750, 1993." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "S. W. BOUGHER" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1988B OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1988 REFERENCE_DESC = " Kasprzak, W.T., A.E. Hedin, H.G. Mayr and H.B. Niemann, Wavelike Perturbations Observed in the Neutral Thermosphere of Venus, Journal of Geophysical Research, vol. 93, 11237-11245, 1988. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. G. MAYR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KEATINGETAL1985 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = "ADVANCES IN SPACE RESEARCH" PUBLICATION_DATE = 1985 REFERENCE_DESC = " Keating, G.M., J.L. Bertaux, S.W. Bougher, T.E. Cravens, R.E. Dickenson, A.E. Hedin, V.A. Krasnopolsky, A.F. Nagy, J.Y. Nicholson, L.J. Paxton and U. von Zahn, 'Models of Venus Neutral Upper Atmosphere: Structure and Composition,' in Venus International Reference Atmosphere, ed. A. V. Kloire, V.I. Moroz and G.M. Keating, Advances in Space Research, vol. 5, 117-171, 1985. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. M. KEATING" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. L. BERTAUX" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "S. W. BOUGHER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "T. E. CRAVENS" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. DICKENSON" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "V. A. KRASNOPOLSKY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. F. NAGY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. Y. NICHOLSON" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "L. J. PAXTON" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "U. VON ZHAN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = MAHAJANETAL1990 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1990 REFERENCE_DESC = " Mahajan, K.K., W.T. Kasprzak, L.H. Brace, H.B. Niemann and W.R. Hoegy, Response of Venus Exospheric Temperature Measured by Neutral Mass Spectrometer to Solar Flux Measured by Langmuir Probe on the Pioneer Venus Orbiter, Journal of Geophysical Research, vol. 95, 1091-1095, 1990. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "K. K. MAHAJAN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LARRY H. BRACE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WALTER R. HOEGY" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = MAYRETAL1988 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1988 REFERENCE_DESC = " Mayr, H.G., I. Harris, W.T. Kasprzak, M. Dube, and F. Variosi, Gravity Waves in the Upper Atmosphere of Venus, Journal of Geophysical Research, vol. 93, 11247-11262, 1988." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. G. MAYR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "I. HARRIS" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "M. DUBE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "F. VARIOSI" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = NIEMANNETAL1979B OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = SCIENCE PUBLICATION_DATE = 1979 REFERENCE_DESC = " Niemann, H.B., R.E. Hartle, W.T. Kasprzak, N.W. Spencer, D.M. Hunten, and G.R. Carignan, Venus Upper Atmosphere Neutral Composition: Preliminary Results from the Pioneer Orbiter, Science, vol. 203, 770-772, 1979. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. HARTLE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N.W. SPENCER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. R. CARIGAN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = NIEMANNETAL1979C OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = SCIENCE PUBLICATION_DATE = 1979 REFERENCE_DESC = " Niemann, H.B., R.E. Hartle, A.E. Hedin, W.T. Kasprzak, N.W. Spencer, D.M. Hunten and G.R. Carignan, Venus Upper Atmosphere Neutral Gas Composition: First Observations of the Diurnal Variations, Science, vol. 205, 54-56, 1979. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. HARTLE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N. W. SPENCER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. R. CARIGAN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = NIEMANNETAL1980A OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Niemann, H.B., W.T. Kasprzak, A.E. Hedin, D.M. Hunten and N.W. Spencer, Mass Spectrometric Measurements of the Neutral Gas Composition of the Thermosphere and Exosphere of Venus, Journal of Geophysical Research, vol. 85, 7817-7827, 1980a. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N. W. SPENCER" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = TAYLORETAL1982 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "UNK" JOURNAL_NAME = "ICARUS" PUBLICATION_DATE = 1982 REFERENCE_DESC = " Taylor, H.A., H.G. Mayr, H.C. Brinton, H.B. Niemann, and R.E. Hartle, Variations in Ion and Neutral Composition at Venus: Evidence of Solar Control of the Formation of the Predawn Bulges in H+ and He, ICARUS, 52, 211, 1982." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. A. TAYLOR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. G. MAYR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. C. BRINTON" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. HARTLE" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = TAYLORETAL1985 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = "ADVANCES IN SPACE RESEARCH" PUBLICATION_DATE = 1985 REFERENCE_DESC = " Taylor, H.A., H.C. Brinton, H.B. Niemann, H.G. Mayr, R.E. Hartle, A. Barnes and J. Larson, In-Situ Results on the Variation of Neutral Atmospheric Hydrogen at Venus, Adv. Sp. Res., 5, 125- 128, 1985." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. A. TAYLOR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. G. MAYR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. C. BRINTON" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. HARTLE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. BARNES" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. LARSON" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = VONZHANETAL1983 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = VENUS PUBLICATION_DATE = 1983 REFERENCE_DESC = " von Zahn, U., S. Kumar, H. Niemann, and R. Prinn, 'Composition of the Venus Atmosphere,' in VENUS, 288-430, University of Arizona Press, Tucson, Ariz., 1983." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "U. VON ZHAN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "S. KUMAR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. PRINN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO END_OBJECT = SCDATASET /********************* NEUTRAL HIGH RES DATASET TEMPLATE **********************/ /* Modifications: */ /* 930414 -- EFRIED */ /* updated Data Set templates according to new std. */ /* Data Set Template -> Spacecraft Data Set Template */ /* event_start_time, event_stop_time -> start_time, stop_time */ /* */ /* Template: Spacecraft Data Set Template Rev: 19890121 */ /* */ /* Note: The following templates form part of a standard set */ /* for the submission of a single dataset to the PDS. */ /* */ /* Hierarchy: SCDATASET */ /* DATASETINFO */ /* DATASETTARG */ /* DSPARMINFO */ /* SCDSHOST */ /* DSREFINFO */ /* REFERENCE */ /* REFAUTHORS */ OBJECT = SCDATASET DATA_SET_ID = "PVO-V-ONMS-3-NEUTRALDENSITY-HIRES-V1.0" OBJECT = DATASETINFO DATA_SET_NAME = "PVO VENUS ONMS CALIBRATED NEUTRAL DENSITY HIGH RES. V1.0" DATA_SET_COLLECTION_MEMBER_FLG = N START_TIME = 1978-12-07T14:29:47.668Z STOP_TIME = 1992-10-07T19:50:36.144Z NATIVE_START_TIME = UNK NATIVE_STOP_TIME = UNK DATA_OBJECT_TYPE = "TIME SERIES" DATA_SET_RELEASE_DATE = 1993-03-31 PROCESSING_LEVEL_ID = 3 PRODUCER_FULL_NAME = "DR. WAYNE KASPRZAK" PRODUCER_INSTITUTION_NAME = "GODDARD SPACE FLIGHT CENTER" SOFTWARE_FLAG = Y DETAILED_CATALOG_FLAG = N PROCESSING_START_TIME = UNK PROCESSING_STOP_TIME = UNK DATA_SET_DESC =" orbits time 3 1978-12-07T14:29:47.668Z 640 1980-09-05T17:15:20.875Z 4961 1992-07-06T00:23:50.044Z 5055 1992-10-07T19:50:36.144Z This data set has at least preliminary composition for every data point measured but not necessarily final composition values. The instrument was designed to determine the composition of the neutral thermosphere/exosphere of Venus. The term composition includes both the type of neutral gases present and their quantitative amount. The measurements begin at the orbit's periapsis altitude and extend to a limiting altitude at which the ambient signal becomes comparable to the gas background and/or detector measurement threshold. The neutral composition includes helium, atomic nitrogen, atomic oxygen, molecular nitrogen, carbon monoxide and carbon dioxide. The data reduction has been described in Niemann et al. (1980a) and Kasprzak et al. (1980). The source of the data and their corrections are summarized below: SPECIES M/E USED COMMENTS He 4 N 30 Surface recombined N and O O 32 Surface recombined O to O2; corrected for CO2 fragmentation corrected for estimated surface recombination of O to CO2(*) N2,CO 14,28 m/e 14 corrected for NO, CO and CO2 fragmentation; m/e 28 corrected for CO2 fragmentation CO2 44 Corrected for surface recombination of O to CO2(*) (*) the correction is based on matching scale height temperatures of O and CO2. The data are from the nonretarding potential mode of the instrument. Data from the retarding mode are consistent with those obtained from the nonretarding mode and have not been included. The data set does not include the factor of 1.6 increase in density needed to maintain compatibility with other data sets as discussed by Hedin et al. (1983). Two data sets are provided: high resolution (HIRES), every point, composition; and low resolution (LORES), 12 second sampled, composition. The LORES data set represents the best estimated composition data and is derived from the HIRES data set. The dataset fields are: YYYY YYYY=4 digit year DDD DDD=3 digit day of year UT Universal Time represented as the number of milliseconds since 1966-01-01T00:00:00Z stored as a double precision floating point number. ORBIT Orbit number MS Mass number - 4 for He 28 for N2 14 for N 29 for CO 16 for O 44 for CO2 F Flag - F for fully corrected P for preliminary (not fully corrected) M for mass flagged (problem point; probably wrong) N for final density negative (only preliminary density given) ODENS Preliminary density (part/cm**3) FDENS Final corrected density (part/cm**3) ANGATK Angle of attack (degrees) PCERR % error in density -1 if error >127% Notes: 1) For CO2 both ODENS and FDENS are given since the final correction to this species depends on a model: (new CO2 density) = (old CO2 density) - 0.019 x (old O density) (new O density) = (old O density) + 0.019 x (old O density) Only the New O density is given. 2) Mass flagged points are usually points that fall excessively beyond range of the main body of the data. They may be wild points, points with wrong mass designations or simply wrong for other reasons. 3) The best estimate of the density is to be found in the F data. 4) Data with errors greater than about 30% should be considered unreliable. 5) The angle of attack is included to help sort out low data values due to antenna shadowing (all species) which occurs beyond 40 degrees and high value ram points seen in He at angles of attack less than 10 degrees. Some of these points have already been mass flagged. In general, it would be best to not include data in these regions." CONFIDENCE_LEVEL_NOTE = " Several criteria were invoked when inserting data for a given orbit: orbit and attitude parameters must exist (project supplied); the spacecraft format and bit rate must be appropriate for acquisition of data by the ONMS; and the command sequence for the instrument must be appropriate for useful determination of atmospheric composition. Cases where useful composition cannot be determined include special test modes (e.g., retarding potential sweeps, filament off) and 1/8 unit amu sweep modes. In addition, composition for the LORES data set cannot be easily determined for unit amu sweep mode. The ONMS was not operational for every orbit nor is every orbit complete due to data gaps introduced by use of telemetry formats for which the ONMS has no instrument output. Useful composition data are gathered from the lowest periapsis altitude to a maximum altitude generally around 250 km (about 300 km for He). The actual maximum altitude depends on the accumulated surface gas buildup acquired from previous orbits which creates a gas background. The gas background was estimated from high altitude averages of the data and for all species, except helium, an inbound signal/background ratio of 2 and an outbound signal/background ratio of 4 were used as cutoff values. In some cases superthermal ions (e.g., Kasprzak et al.,1982) were observed at low altitudes (e.g., below 300 km for orbit 219) and these were removed when visually detected. Some problems have been observed in the high altitude data very near cutoff, particularly for outbound N2. Several data points were never removed and appear higher than the expected extrapolation of the data to that time. Residual spin modulation which had not been completely removed is evident in the processed data. The source of the spin residuals are the gas/surface adsorption/desorption effects which were not removed from the data and a noncosine behavior for the response of the ion source density with angle of attack. Another feature observed occasionally at large angles of attack (>40 degrees) is a reduction of the data when compared to data at lower angles of attack. This has been determined to be due to antenna shadowing; that is, the ONMS geometric view cone 'sees' the spacecraft antenna at extreme angles of attack. Occasionally near minimum angle of attack (<10 degrees), enhanced data points are observed for m/e=4 (He channel) which are apparently high energy ions/neutrals traveling along the tube axis and being detected. The more extreme points in either of these two cases have been mass flagged. The data time spacing depends on the spacecraft bit rate and format, and the particular instrument commands executed. Usually programmed mass format was used but occasionally unit amu and 1/8 amu sweeps were implemented. Several orbits switched from low electron energy to high electron energy and as a result there may be a discontinuity at the transition point. The 1/8 amu sweep data have not been included. Atomic nitrogen was measured in programmed mass mode only after orbit 190. Orbits 1-19 generally do not have reliable relative composition due to the fact that gas-surface processes in the ion source had not stabilized. This affects all surface reactive species except He. Isolated (one or two points per several spin cycles) high resolution data points are occasionally observed and they should be regarded as erroneous points which are more likely wrong than right. The error associated with the points is more an indication of data quality than of absolute uncertainty. It contains the statistical error of the data determined for the principle m/e used for the species from the detector signal plus the errors coming from any other species used to correct the data. It also contains a contribution which is proportional to the background/signal ratio. The total relative error is at least an additional 5-10% above this value." END_OBJECT = DATASETINFO /* */ /******************************************************************************/ /* */ OBJECT = DATASETTARG TARGET_NAME = VENUS END_OBJECT = DATASETTARG OBJECT = DSPARMINFO SAMPLING_PARAMETER_NAME = TIME SAMPLING_PARAMETER_RESOLUTION = UNK MINIMUM_SAMPLING_PARAMETER = "N/A" MAXIMUM_SAMPLING_PARAMETER = "N/A" SAMPLING_PARAMETER_INTERVAL = "N/A" MINIMUM_AVAILABLE_SAMPLING_INT = 0.25 SAMPLING_PARAMETER_UNIT = SECOND DATA_SET_PARAMETER_NAME = "NEUTRAL DENSITY" NOISE_LEVEL = UNK DATA_SET_PARAMETER_UNIT = "PARTICLES/CM**3" /* SAMPLING_DESCRIPTION = " */ /* */ /* This data set has at least preliminary composition for every data */ /* point measured but not necessarily final composition values. The */ /* actual sampling frequency varies with spacecraft telemetry rate." */ END_OBJECT = DSPARMINFO OBJECT = SCDSHOST INSTRUMENT_HOST_ID = PVO INSTRUMENT_ID = ONMS END_OBJECT = SCDSHOST /* */ /******************************************************************************/ /* */ OBJECT = DSREFINFO REFERENCE_KEY_ID = BRACEETAL1987 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOTAIL" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1987 REFERENCE_DESC = " Brace, L.H., W.T. Kasprzak, H.A. Taylor, R.F. Theis, C.T. Russell, A. Barnes, J.D. Mihalov and D.M. Hunten, The Ionotail of Venus: Its Configuration and Evidence for Ion Escape, J. of Geophys. Res, vol 92, 15-26, 1987. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LARRY H. BRACE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "HARRY A. TAYLOR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "ROBERT F. THEIS" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "CHRISTOPHER T. RUSSELL" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "AARON BARNES" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. D. MIHALOV" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = GUENTHER1989 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "PLASMA INSTRUMENTS" JOURNAL_NAME = UNK PUBLICATION_DATE = 1989 REFERENCE_DESC = " Guenther, Y.P., 'Pioneer Venus Neutral Mass Spectrometer,' NASA/Goddard Space Flight Center Summer Institute on Atmospheric Science, Laboratory for Planetary Atmospheres, Code 910, 1989. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "Y. P. GUENTHER" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = HEDINETAL1983 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1983 REFERENCE_DESC = " Hedin, A.E., H.B. Niemann, W.T. Kasprzak and A. Seiff, Global Empirical Model of the Venus Thermosphere, Journal of Geophysical Research, vol. 88, 73-83, 1983." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. SEIFF" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = "HOEGYETAL1990" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1990 REFERENCE_DESC = " Hoegy, W.R., L.H. Brace, W.T. Kasprzak and C.T. Russell, Small-Scale Plasma, Magnetic, and Neutral Density Fluctuations in the Nightside of Venus Ionosphere, Journal of Geophysical Research, vol. 95, 4085-4102, 1990. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WALTER R. HOEGY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LARRY H. BRACE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "CHRISTOPHER T. RUSSELL" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KARETAL1990 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUE THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1990 REFERENCE_DESC = " Kar, J., R. Paul, R. Kohli, K.K. Mahajan, W.T. Kasprzak and H.B. Niemann, On the Response of Exospheric Temperature on Venus to Solar Wind Conditions, Submitted to Journal of Geophysical Research, Oct. 1990." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. KAR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. PAUL" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. KOHLI" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "K. K. MAHAJAN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1980 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = "Geophysical Research Letters" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Kasprzak, W.T., A.E. Hedin, H.B. Niemann and N.W. Spencer, Atomic Nitrogen in the Upper Atmosphere of Venus, Geophysical Research Letters, vol. 7,106-108, 1980. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N. W. SPENCER" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1982 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOSPHERE" JOURNAL_NAME = "PLANETARY SPACE SCIENCES" PUBLICATION_DATE = 1982 REFERENCE_DESC = " Kasprzak. W.T., H.A. Taylor, L.H. Brace and H.B. Niemann, Observations of Energetic Ions Near the Venus Ionopause, Planetary Space Sciences, vol. 30, 1107-1115, 1982. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "HARRY A. TAYLOR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LARRY H. BRACE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1987 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOTAIL" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1987 REFERENCE_DESC = " Kasprzak, W.T., H.B. Niemann and P. Mahaffy, Observations of Energetic Ions on the Nightside of Venus, Journal of Geophysical Research, vol. 32, 291-298, 1987. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "P. MAHAFFY" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAK&NIEMANN1988 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOSPHERE" JOURNAL_NAME = "NASA Technical Memorandum 100717" PUBLICATION_DATE = 1988 REFERENCE_DESC = " Kasprzak, W.T. and H.B. Niemann, Fast O+ Ion Flow Observed Around Venus at Low Altitudes, NASA Technical Memorandum 100717, December 1988. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1988 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1988 REFERENCE_DESC = " Kasprzak, W.T., A.E. Hedin, H.G. Mayr and H.B. Niemann, Wavelike Perturbations Observed in the Neutral Thermosphere of Venus, Journal of Geophysical Research, vol. 93, 11237-11245, 1988. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. G. MAYR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAK1990 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS" JOURNAL_NAME = "NASA Technical Memorandum 100761" PUBLICATION_DATE = 1990 REFERENCE_DESC = " Kasprzak, W.T., The Pioneer Venus Orbiter: 11 Years of Data, NASA Technical Memorandum 100761, May 1990. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1991 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOTAIL" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1991 REFERENCE_DESC = " Kasprzak, W.T., J.M. Grebowsky, H.B. Niemann and L.H. Brace, Superthermal > 36 eV Ions Observed in the Near Tail Region of Venus by the Pioneer Venus Orbiter Neutral Mass Spectrometer, J. Geophys. Res., 96, 11715-11187, 1991." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. M. GREBOWSKY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LARRY H. BRACE" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAK&NIEMANN1991 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOSPHERE" JOURNAL_NAME = "PLANET" PUBLICATION_DATE = 1991 REFERENCE_DESC = " Kasprzak, W.T. and H.B. Niemann, Evidence for Enhanced Dynamic Flow in Ionospheric Holes from the Pioneer Venus Neutral Mass Spectrometer, Planet. Sp. Sci., 40, 33-45, 1992." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KEATINGETAL1985 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = "ADVANCES IN SPACE RESEARCH" PUBLICATION_DATE = 1985 REFERENCE_DESC = " Keating, G.M., J.L. Bertaux, S.W. Bougher, T.E. Cravens, R.E. Dickenson, A.E. Hedin, V.A. Krasnopolsky, A.F. Nagy, J.Y. Nicholson, L.J. Paxton and U. von Zahn, 'Models of Venus Neutral Upper Atmosphere: Structure and Composition,' in Venus International Reference Atmosphere, ed. A. V. Kloire, V.I. Moroz and G.M. Keating, Advances in Space Research, vol. 5, 117-171, 1985. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. M. KEATING" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. L. BERTAUX" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "S. W. BOUGHER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "T. E. CRAVENS" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. DICKENSON" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "V. A. KRASNOPOLSKY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. F. NAGY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. Y. NICHOLSON" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "L. J. PAXTON" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "U. VON ZHAN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = MAHAJANETAL1990 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1990 REFERENCE_DESC = " Mahajan, K.K., W.T. Kasprzak, L.H. Brace, H.B. Niemann and W.R. Hoegy, Response of Venus Exospheric Temperature Measured by Neutral Mass Spectrometer to Solar Flux Measured by Langmuir Probe on the Pioneer Venus Orbiter, Journal of Geophysical Research, vol. 95, 1091-1095, 1990. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "K. K. MAHAJAN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LARRY H. BRACE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WALTER R. HOEGY" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = MAYRETAL1988 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1988 REFERENCE_DESC = " Mayr, H.G., I. Harris, W.T. Kasprzak, M. Dube, and F. Variosi, Gravity Waves in the Upper Atmosphere of Venus, Journal of Geophysical Research, vol. 93, 11247-11262, 1988." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. G. MAYR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "I. HARRIS" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "M. DUBE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "F. VARIOSI" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = NIEMANNETAL1979B OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = SCIENCE PUBLICATION_DATE = 1979 REFERENCE_DESC = " Niemann, H.B., R.E. Hartle, W.T. Kasprzak, N.W. Spencer, D.M. Hunten, and G.R. Carignan, Venus Upper Atmosphere Neutral Composition: Preliminary Results from the Pioneer Orbiter, Science, vol. 203, 770-772, 1979. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. HARTLE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N.W. SPENCER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. R. CARIGAN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = NIEMANNETAL1979B OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = SCIENCE PUBLICATION_DATE = 1979 REFERENCE_DESC = " Niemann, H.B., R.E. Hartle, A.E. Hedin, W.T. Kasprzak, N.W. Spencer, D.M. Hunten and G.R. Carignan, Venus Upper Atmosphere Neutral Gas Composition: First Observations of the Diurnal Variations, Science, vol. 205, 54-56, 1979. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. HARTLE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N. W. SPENCER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. R. CARIGAN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = NIEMANNETAL1980A OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Niemann, H.B., W.T. Kasprzak, A.E. Hedin, D.M. Hunten and N.W. Spencer, Mass Spectrometric Measurements of the Neutral Gas Composition of the Thermosphere and Exosphere of Venus, Journal of Geophysical Research, vol. 85, 7817-7827, 1980a. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N. W. SPENCER" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = NIEMANNETAL1980B OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "SPECTROMETRY" JOURNAL_NAME = "IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Niemann, H.B., J.R. Booth, J.E. Cooley, R.E. Hartle, W.T. Kasprzak, N.W. Spencer, S.H. Way, D.M. Hunten and G.R. Carignan, Pioneer Venus Orbiter Neutral Gas Mass Spectrometer, IEEE Trans. on Geoscience and Remote Sensing, vol. GE-18 (1), 60-65, 1980b. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. R. BOOTH" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. E. COOLEY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. HARTLE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N. W. SPENCER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "S. H. WAY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. R. CARIGAN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = "NIEMANN&KASPRZAK1983" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "SPECTROMETRY" JOURNAL_NAME = "ADVANCES IN SPACE RESEARCH" PUBLICATION_DATE = 1983 REFERENCE_DESC = " Niemann, H.B. and W.T. Kasprzak, Comparative Neutral Composition Instrumentation and New Results, Advances in Space Research, vol. 2, 261-270, 1983. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = VONZHANETAL1983 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = VENUS PUBLICATION_DATE = 1983 REFERENCE_DESC = " von Zahn, U., S. Kumar, H. Niemann, and R. Prinn, 'Composition of the Venus Atmosphere,' in VENUS, 288-430, University of Arizona Press, Tucson, Ariz., 1983." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "U. von Zhan" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "S. Kumar" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. PRINN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO END_OBJECT = SCDATASET /********************* ION LOCATION DATASET TEMPLATE **************************/ /* Template: Spacecraft Data Set Template Rev: 19890121 */ /* Note: The following templates form part of a standard set */ /* for the submission of a single dataset to the PDS. */ /* Hierarchy: SCDATASET */ /* DATASETINFO */ /* DATASETTARG */ /* DSPARMINFO */ /* SCDSHOST */ /* DSREFINFO */ /* REFERENCE */ /* REFAUTHORS */ OBJECT = SCDATASET DATA_SET_ID = "PVO-V-ONMS-5-SUPERTHERMALIONLOC-V1.0" OBJECT = DATASETINFO DATA_SET_NAME = "PVO VENUS ONMS DERIVED SUPERTHERMAL ION LOCATION V1.0" DATA_SET_COLLECTION_MEMBER_FLG = N START_TIME = 1978-12-05T15:06:25.000Z STOP_TIME = 1992-10-07T19:50:29.000Z NATIVE_START_TIME = UNK NATIVE_STOP_TIME = UNK DATA_OBJECT_TYPE = "TIME SERIES" DATA_SET_RELEASE_DATE = UNK PROCESSING_LEVEL_ID = 5 PRODUCER_FULL_NAME = "DR. WAYNE KASPRZAK" PRODUCER_INSTITUTION_NAME = "GODDARD SPACE FLIGHT CENTER" SOFTWARE_FLAG = Y DETAILED_CATALOG_FLAG = N PROCESSING_START_TIME = UNK PROCESSING_STOP_TIME = UNK DATA_SET_DESC = " orbits time 1 1978-12-05T15:06:25.000Z 645 1980-09-10T17:30:20.000Z 4710 1991-12-29T00:40:49.000Z 5055 1992-10-07T19:50:29.000Z This dataset contains start and stop times/locations where superthermal ions were detected by the Neutral Mass Spectrometer instrument aboard the Pioneer Venus Orbiter. The instrument detected superthermal, energetic or fast ions whose energy exceeds 36 eV in the spacecraft frame of reference. These ions were observed in early orbits during measurements of the neutral density near periapsis, have an erratic and unpredictable signature, and occur at too high an altitude to be due to the neutral atmosphere. When the altitude of periapsis increased above the point where neutral density measurements could be made, the instrument was configured specifically to detect superthermal ions. In general, for orbit numbers 1 to 645, data were taken from the RPA mode. The gas background signal with the filament on is about a factor of 10 less in this mode than in non-RPA mode, resulting in a lower detection threshold. For orbit numbers above 923, the instrument was deliberately configured with the filament off and non-RPA mode data was used. For mass 16 the RPA voltage is about +3.8 volts. The data reduction process has been described in Kasprzak et al. (1987). The method used to reduce the data assumes cylindrical symmetry of the ion source. In actual fact, the source is asymmetrical in its angular response (Guenther, 1989). This can introduce as much as a factor of 2 scatter in the data. No simple solution has been found for modeling this asymmetry since the actual ion drift vector is unknown. The minimum energy of an ion detectable by the ONMS in this ion mode is 35.9 eV. The maximum transmission is assumed to occur about 10 V above this value. On the nightside of Venus the spacecraft potential is negative and the most probable ion energy is near 40 eV. The ion species regularly monitored include: He+, N+, O+, N+ and/or CO+ and CO2+. Because of the paucity of data at other mass numbers only mass 16 (atomic oxygen) has been reduced to a flux and number density. As part of the reduction process the angle in the ecliptic plane of the apparent ion flow in spacecraft reference frame has been deduced. The flux values are estimated in the spacecraft reference frame relative to spacecraft ground. The density is computed from the flux by dividing it by a speed corresponding to 40 eV. No correction has been applied to the angle, density or flux in order to remove the effect of spacecraft velocity. The dataset fields are: VARIABLE COMMENT -------------------------------------------------------- ORBIT Orbit number MASS Mass number of species 4 He+ 12 C+ 14 N+ 16 O+ 28 CO+ and/or N2+ 30 NO+ 32 O2+ 44 CO2+ BTIME Beginning time -| BTPER Time from periapsis (sec) | BALTIT Altitude in (km) |-- START BSZA Solar zenith angle (deg) | BLAT Local solar time (hr) -| ETIME Ending Time -| ETPER Time from periapsis (sec) | EALTIT Altitude in (km) |-- FINISH ESZA Solar zenith angle (deg) | ELAT Local solar time (hr) -|" CONFIDENCE_LEVEL_NOTE = " In order to fit the data, a minimum of 30 points were required in 36 seconds. In addition, the maximum to minimum count ratio was required to be factor of 3 or greater in order to insure that there was a definitive spin modulation. The center 12 seconds of data is divided by the fitting function to derive the equivalent flux for that point. The center of the new fitting interval is adjusted so that it is centered on the expected signal maximum predicted from the previous interval fit. As a result of this method of fitting, discontinuities may exist near minimum angle of attack where one 12 second interval adjoins the next interval. See Kasprzak et al. (1987). Kasprzak, W.T., H.B. Niemann and P. Mahaffy, Observations of Energetic Ions on the Nightside of Venus, Journal of Geophysical Research, vol. 32, 291-298, 1987. " END_OBJECT = DATASETINFO OBJECT = DATASETTARG TARGET_NAME = VENUS END_OBJECT = DATASETTARG OBJECT = DSPARMINFO SAMPLING_PARAMETER_NAME = "N/A" SAMPLING_PARAMETER_RESOLUTION = "N/A" MINIMUM_SAMPLING_PARAMETER = "N/A" MAXIMUM_SAMPLING_PARAMETER = "N/A" SAMPLING_PARAMETER_INTERVAL = "N/A" MINIMUM_AVAILABLE_SAMPLING_INT = "N/A" SAMPLING_PARAMETER_UNIT = "N/A" DATA_SET_PARAMETER_NAME = "LOCATION" NOISE_LEVEL = "N/A" DATA_SET_PARAMETER_UNIT = "N/A" END_OBJECT = DSPARMINFO OBJECT = SCDSHOST INSTRUMENT_HOST_ID = PVO INSTRUMENT_ID = ONMS END_OBJECT = SCDSHOST OBJECT = DSREFINFO REFERENCE_KEY_ID = NIEMANNETAL1980B OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "SPECTROMETRY" JOURNAL_NAME = "IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Niemann, H.B., J.R. Booth, J.E. Cooley, R.E. Hartle, W.T. Kasprzak, N.W. Spencer, S.H. Way, D.M. Hunten and G.R. Carignan, Pioneer Venus Orbiter Neutral Gas Mass Spectrometer, IEEE Trans. on Geoscience and Remote Sensing, vol. GE-18 (1), 60-65, 1980b. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. R. BOOTH" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. E. COOLEY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. HARTLE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N. W. SPENCER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "S. H. WAY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. R. CARIGAN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = "NIEMANN&KASPRZAK1983" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "SPECTROMETRY" JOURNAL_NAME = "ADVANCES IN SPACE RESEARCH" PUBLICATION_DATE = 1983 REFERENCE_DESC = " Niemann, H.B. and W.T. Kasprzak, Comparative Neutral Composition Instrumentation and New Results, Advances in Space Research, vol. 2, 261-270, 1983. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = "KASPRZAK1987" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "SPECTROMETRY" JOURNAL_NAME = "JOURNAL OF GEOPHYICAL RESEARCH" PUBLICATION_DATE = 1987 REFERENCE_DESC = " Kasprzak, W.T., H.B. Niemann and P. Mahaffy, Observations of Energetic Ions on the Nightside of Venus, Journal of Geophysical Research, vol. 32, 291-298, 1987." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "P. MAHAFFY" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO END_OBJECT = SCDATASET /********** ONMS ION Dataset Template *****************************************/ /* Modifications: */ /* 930414 -- EFRIED */ /* updated Data Set templates according to new std. */ /* Data Set Template -> Spacecraft Data Set Template */ /* event_start_time, event_stop_time -> start_time, stop_time */ /* */ /* Template: Data Set Template Rev: 19890121 */ /* */ /* Note: The following templates form part of a standard set */ /* for the submission of a single dataset to the PDS. */ /* */ /* Hierarchy: SCDATASET */ /* DATASETINFO */ /* DATASETTARG */ /* DSPARMINFO */ /* SCDSHOST */ /* DSREFINFO */ /* REFERENCE */ /* REFAUTHORS */ OBJECT = SCDATASET DATA_SET_ID = "PVO-V-ONMS-4-IONMAXCOUNTRATE-12SEC-V1.0" OBJECT = DATASETINFO DATA_SET_NAME = "PVO VENUS ONMS BROWSE SUPRTHRML ION MAX COUNT RATE 12S V1.0" 123456789012345678901234567890123456789012345678901234567890 DATA_SET_COLLECTION_MEMBER_FLG = N START_TIME = 1978-12-05T15:06:31.820Z STOP_TIME = 1992-10-07T19:50:28.680Z NATIVE_START_TIME = UNK NATIVE_STOP_TIME = UNK DATA_OBJECT_TYPE = "TIME SERIES" DATA_SET_RELEASE_DATE = 1993-03-31 PROCESSING_LEVEL_ID = 4 PRODUCER_FULL_NAME = "DR. WAYNE KASPRZAK" PRODUCER_INSTITUTION_NAME = "GODDARD SPACE FLIGHT CENTER" SOFTWARE_FLAG = Y DETAILED_CATALOG_FLAG = N PROCESSING_START_TIME = UNK PROCESSING_STOP_TIME = UNK DATA_SET_DESC =" This data set represents the maximum count rate per second in a 12 second period beginning with the time of the first data point for a given mass number. Although species other than O+ cannot be reduced to to a flux and direction it is possible to estimate the approximate flux from the maximum count rate per second occurring within one spin period (about 12 seconds). The maximum count rate can be approximately converted to a flux using: [4.E7 (particles/cm**2/sec)]/[1.E4 (counts/sec)]. This sensitivity is for O+. At higher mass numbers the sensitivity is less, being about a factor of 2.5 lower for Ar+. Background The instrument has detected superthermal, energetic or fast ions whose energy exceeds 36 eV in the spacecraft frame of reference. These ions were observed in early orbits during measurements of the neutral density near periapsis, have an erratic and unpredictable signature, and occur at too high an altitude to be due to the neutral atmosphere. When the altitude of periapsis increased above the point where sensible neutral density measurements could be made, the instrument was configured specifically to detect superthermal ions. In general, for orbit numbers 1 to 645, data were taken from the RPA mode. The gas background signal with the filament on is about a factor of 10 less in this mode than in non-RPA mode, resulting in a lower detection threshold. For orbit numbers above 923, the instrument was deliberately configured with the filament off and non-RPA mode data was used. For mass 16 the RPA voltage is about +3.8 volts. The superthermal ion species regularly monitored include: He+, N+, O+, (N+ + CO+), and CO2+. Because of the paucity of data at other mass numbers only mass 16 (atomic oxygen) has been reduced to a flux and number density. As part of the reduction process the angle in the ecliptic plane of the apparent ion flow in spacecraft reference frame has been deduced. The flux values are estimated in the spacecraft reference frame relative to spacecraft ground. The density is computed from the flux by dividing it by a speed corresponding to 40 eV. No correction has been applied to the angle, density or flux in order to remove the effect of spacecraft velocity. The data reduction process has been described in Kasprzak et al. (1987). The method used to reduce the data assumes cylindrical symmetry of the ion source. In actual fact, the source is asymmetrical in its angular response (Guenther, 1989). This can introduce as much as a factor of 2 scatter in the data. No simple solution has been found for modeling this asymmetry since the actual ion drift vector is unknown. The minimum energy of an ion detectable by the ONMS in this ion mode is 35.9 eV. The maximum transmission is assumed to occur about 10 V above this value. On the nightside of Venus the spacecraft potential is negative and the most probable ion energy is near 40 eV. The dataset fields are: VARIABLE COMMENT -------------------------------------------------------- YEAR YY=2 digit year (e.g. 78 for 1978) DOY DDD=3 digit day of year (e.g. 053) UT Universal time represented as the number of milliseconds since 1966-01-01T00:00:00Z stored as a double precision floating point number. ORBIT Orbit number TFP Time from periapsis (sec) MASS Mass number - 4 for He+ 12 for C+ 14 for N+ 16 for O+ 28 for N2+ and/or CO+ 30 for NO+ 32 for O2+ 44 for CO2+ PULSE Maximum count rate/sec in 12 second interval VALT Altitude (km) VLAT Latitude (deg N) VLST Local solar time (hr) VSZA Solar zenith angle (deg) Kasprzak, W.T., H.B. Niemann and P. Mahaffy, Observations of Energetic Ions on the Nightside of Venus, Journal of Geophysical Research, vol. 32, 291-298, 1987." /* */ /******************************************************************************/ /* */ CONFIDENCE_LEVEL_NOTE = " In order to fit the data a minimum of 30 points were required in 36 seconds. In addition, the maximum to minimum count ratio was required to be factor of 3 or greater in order to insure that there was a definitive spin modulation. The center 12 seconds of data is divided by the fitting function to derive the equivalent flux for that point. The center of the new fitting interval is adjusted so that it is centered on the expected signal maximum predicted from the previous interval fit. As a result of this method of fitting, discontinuities may exist near minimum angle of attack where one 12 second interval adjoins the next interval. See Kasprzak et al. (1987). Kasprzak, W.T., H.B. Niemann and P. Mahaffy, Observations of Energetic Ions on the Nightside of Venus, Journal of Geophysical Research, vol. 32, 291-298, 1987. " END_OBJECT = DATASETINFO /* */ /******************************************************************************/ /* */ OBJECT = DATASETTARG TARGET_NAME = VENUS END_OBJECT = DATASETTARG OBJECT = DSPARMINFO SAMPLING_PARAMETER_NAME = TIME SAMPLING_PARAMETER_RESOLUTION = 12.0 MINIMUM_SAMPLING_PARAMETER = "N/A" MAXIMUM_SAMPLING_PARAMETER = "N/A" SAMPLING_PARAMETER_INTERVAL = 12.0 MINIMUM_AVAILABLE_SAMPLING_INT = 12.0 SAMPLING_PARAMETER_UNIT = SECOND DATA_SET_PARAMETER_NAME = "ION RATE" NOISE_LEVEL = UNK DATA_SET_PARAMETER_UNIT = "PARTICLES/SECOND" /* SAMPLING_PARAMETER_DESC = " /* This data set represents the maximum count rate per second in a /* 12 second period beginning with the time of the first data point for /* a given mass number." END_OBJECT = DSPARMINFO OBJECT = SCDSHOST INSTRUMENT_HOST_ID = PVO INSTRUMENT_ID = ONMS END_OBJECT = SCDSHOST /* */ /******************************************************************************/ /* */ OBJECT = DSREFINFO REFERENCE_KEY_ID = NIEMANNETAL1980B OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "SPECTROMETRY" JOURNAL_NAME = "IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Niemann, H.B., J.R. Booth, J.E. Cooley, R.E. Hartle, W.T. Kasprzak, N.W. Spencer, S.H. Way, D.M. Hunten and G.R. Carignan, Pioneer Venus Orbiter Neutral Gas Mass Spectrometer, IEEE Trans. on Geoscience and Remote Sensing, vol. GE-18 (1), 60-65, 1980b. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. R. BOOTH" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. E. COOLEY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. HARTLE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N. W. SPENCER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "S. H. WAY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. R. CARIGAN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = "NIEMANN&KASPRZAK1983" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "SPECTROMETRY" JOURNAL_NAME = "ADVANCES IN SPACE RESEARCH" PUBLICATION_DATE = 1983 REFERENCE_DESC = " Niemann, H.B. and W.T. Kasprzak, Comparative Neutral Composition Instrumentation and New Results, Advances in Space Research, vol. 2, 261-270, 1983. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = "KASPRZAK1987" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "SPECTROMETRY" JOURNAL_NAME = "JOURNAL OF GEOPHYICAL RESEARCH" PUBLICATION_DATE = 1987 REFERENCE_DESC = " Kasprzak, W.T., H.B. Niemann and P. Mahaffy, Observations of Energetic Ions on the Nightside of Venus, Journal of Geophysical Research, vol. 32, 291-298, 1987." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "P. MAHAFFY" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO END_OBJECT = SCDATASET /******************* ONMS Superthermal Low Res Dataset Template ***************/ /* Modifications: */ /* 930414 -- EFRIED */ /* updated Data Set templates according to new std. */ /* Data Set Template -> Spacecraft Data Set Template */ /* event_start_time, event_stop_time -> start_time, stop_time */ /* */ /* Template: Spacecraft Data Set Template Rev: 19890121 */ /* */ /* Note: The following templates form part of a standard set */ /* for the submission of a single dataset to the PDS. */ /* Hierarchy: SCDATASET */ /* DATASETINFO */ /* DATASETTARG */ /* DSPARMINFO */ /* SCDSHOST */ /* DSREFINFO */ /* REFERENCE */ /* REFAUTHORS */ OBJECT = SCDATASET DATA_SET_ID = "PVO-V-ONMS-4-SUPERTHRMLOXYGN-12SEC-V1.0" OBJECT = DATASETINFO DATA_SET_NAME = "PVO VENUS ONMS BROWSE SUPERTHERMAL OXYGEN 12 SECOND V1.0" DATA_SET_COLLECTION_MEMBER_FLG = N START_TIME = 1978-12-05T15:07:22.817Z STOP_TIME = 1992-07-20T00:22:15.544Z NATIVE_START_TIME = UNK NATIVE_STOP_TIME = UNK DATA_OBJECT_TYPE = "TIME SERIES" DATA_SET_RELEASE_DATE = 1993-03-31 PROCESSING_LEVEL_ID = 4 PRODUCER_FULL_NAME = "DR. WAYNE KASPRZAK" PRODUCER_INSTITUTION_NAME = "GODDARD SPACE FLIGHT CENTER" SOFTWARE_FLAG = Y DETAILED_CATALOG_FLAG = N PROCESSING_START_TIME = UNK PROCESSING_STOP_TIME = UNK DATA_SET_DESC =" The instrument has detected superthermal, energetic or fast ions whose energy exceeds 36 eV in the spacecraft frame of reference. These ions were observed in early orbits during measurements of the neutral density near periapsis, have an erratic and unpredictable signature, and occur at too high an altitude to be due to the neutral atmosphere. When the altitude of periapsis increased above the point where sensible neutral density measurements could be made, the instrument was configured specifically to detect superthermal ions. In general, for orbit numbers 1 to 645, data were taken from the RPA mode. The gas background signal with the filament on is about a factor of 10 less in this mode than in non-RPA mode, resulting in a lower detection threshold. For orbit numbers above 923, the instrument was deliberately configured with the filament off and non-RPA mode data was used. For mass 16 the RPA voltage is about +3.8 volts. The data reduction process has been described in Kasprzak et al. (1987). The method used to reduce the data assumes cylindrical symmetry of the ion source. In actual fact, the source is asymmetrical in its angular response (Guenther, 1989). This can introduce as much as a factor of 2 scatter in the data. No simple solution has been found for modeling this asymmetry since the actual ion drift vector is unknown. The minimum energy of an ion detectable by the ONMS in this ion mode is 35.9 eV. The maximum transmission is assumed to occur about 10 V above this value. On the nightside of Venus the spacecraft potential is negative and the most probable ion energy is near 40 eV. The ion species regularly monitored include: He+, N+, O+, (N+ + CO+), and CO2+. Because of the paucity of data at other mass numbers only mass 16 (atomic oxygen) has been reduced to a flux and number density. As part of the reduction process the angle in the ecliptic plane of the apparent ion flow in spacecraft reference frame has been deduced. The flux values are estimated in the spacecraft reference frame relative to spacecraft ground. The density is computed from the flux by dividing it by a speed corresponding to 40 eV. No correction has been applied to the angle, density or flux in order to remove the effect of spacecraft velocity. Several parameters result from the fit: 1) the best estimate of the flux for the interval (used to generate the low resolution (LORES) data set); 2) the phase shift of signal maximum with respect to that predicted by the position of the velocity vector and its error; 3) the fitting parameter B (Kasprzak et al., 1987); and 4) the effective angle of attack. Other items can be derived from this data: 1) the apparent direction of the ion flow projected into the ecliptic plane; and 2) one component of the ion drift perpendicular to the plane of axis of the ONMS and the spin axis. The phase angle is negative if the predicted signal maximum from the spacecraft velocity is ahead of the true signal maximum when viewed along the -Z spacecraft axis with clockwise rotation. The drift component is derived from the condition that the total relative velocity in the moving reference frame has no component perpendicular to the (ONMS axis, Z axis) plane. The data values of the LORES data set are sampled approximately once per 12 seconds based on GMT times that have been supplied by the Pioneer Venus Project. Each representative data point is constructed using an exponentially weighted average of the data over a 24 second interval centered at sample point time. The dataset fields are: VARIABLE COMMENT -------------------------------------------------------- YEAR YYYY=4 digit year DOY DDD=3 digit day of year UT Universal time represented as the number of milliseconds since 1966-01-01T00:00:00Z stored as a double precision floating point number. ORBIT Orbit number PSEC Seconds after periapsis DO+ Density of superthermal atomic oxygen in cm{-3} FO+ Flux of superthermal atomic oxygen in cm{-2} s{-1} FANG Apparent angle, in degrees, of the ion flow in the ecliptic plane measured with respect to the sun VALT Altitude above the mean surface of Venus in km VLAT Venus latitude in degrees VLST Venus local solar time in hr VSZA Venus solar zenith angle in degrees Kasprzak, W.T., H.B. Niemann and P. Mahaffy, Observations of Energetic Ions on the Nightside of Venus, Journal of Geophysical Research, vol. 32, 291-298, 1987." /* */ /******************************************************************************/ /* */ CONFIDENCE_LEVEL_NOTE = " In order to fit the data a minimum of 30 points were required in 36 seconds. In addition, the maximum to minimum count ratio was required to be factor of 3 or greater in order to insure that there was a definitive spin modulation. The center 12 seconds of data is divided by the fitting function to derive the equivalent flux for that point. The center of the new fitting interval is adjusted so that it is centered on the expected signal maximum predicted from the previous interval fit. As a result of this method of fitting, discontinuities may exist near minimum angle of attack where one 12 second interval adjoins the next interval. See Kasprzak et al. (1987). Kasprzak, W.T., H.B. Niemann and P. Mahaffy, Observations of Energetic Ions on the Nightside of Venus, Journal of Geophysical Research, vol. 32, 291-298, 1987. " END_OBJECT = DATASETINFO /* */ /******************************************************************************/ /* */ OBJECT = DATASETTARG TARGET_NAME = VENUS END_OBJECT = DATASETTARG OBJECT = DSPARMINFO SAMPLING_PARAMETER_NAME = TIME SAMPLING_PARAMETER_RESOLUTION = 12.0 MINIMUM_SAMPLING_PARAMETER = "N/A" MAXIMUM_SAMPLING_PARAMETER = "N/A" SAMPLING_PARAMETER_INTERVAL = 12.0 MINIMUM_AVAILABLE_SAMPLING_INT = 12.0 SAMPLING_PARAMETER_UNIT = SECOND DATA_SET_PARAMETER_NAME = "ION DENSITY" NOISE_LEVEL = UNK DATA_SET_PARAMETER_UNIT = "PARTICLES/CM**3" END_OBJECT = DSPARMINFO OBJECT = DSPARMINFO SAMPLING_PARAMETER_NAME = TIME SAMPLING_PARAMETER_RESOLUTION = 12.0 MINIMUM_SAMPLING_PARAMETER = "N/A" MAXIMUM_SAMPLING_PARAMETER = "N/A" SAMPLING_PARAMETER_INTERVAL = 12.0 MINIMUM_AVAILABLE_SAMPLING_INT = 12.0 SAMPLING_PARAMETER_UNIT = SECOND DATA_SET_PARAMETER_NAME = "ION FLUX" NOISE_LEVEL = UNK DATA_SET_PARAMETER_UNIT = "PARTICLES/(CM^2 * SECOND)" END_OBJECT = DSPARMINFO OBJECT = SCDSHOST INSTRUMENT_HOST_ID = PVO INSTRUMENT_ID = ONMS END_OBJECT = SCDSHOST /* */ /******************************************************************************/ /* */ OBJECT = DSREFINFO REFERENCE_KEY_ID = BRACEETAL1987 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOTAIL" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1987 REFERENCE_DESC = " Brace, L.H., W.T. Kasprzak, H.A. Taylor, R.F. Theis, C.T. Russell, A. Barnes, J.D. Mihalov and D.M. Hunten, The Ionotail of Venus: Its Configuration and Evidence for Ion Escape, J. of Geophys. Res, vol 92, 15-26, 1987. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LARRY H. BRACE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "HARRY A. TAYLOR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "ROBERT F. THEIS" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "CHRISTOPHER T. RUSSELL" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "AARON BARNES" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. D. MIHALOV" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = GUENTHER1989 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "PLASMA INSTRUMENTS" JOURNAL_NAME = UNK PUBLICATION_DATE = 1989 REFERENCE_DESC = " Guenther, Y.P., 'Pioneer Venus Neutral Mass Spectrometer,' NASA/Goddard Space Flight Center Summer Institute on Atmospheric Science, Laboratory for Planetary Atmospheres, Code 910, 1989. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "Y. P. GUENTHER" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = HEDINETAL1983 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1983 REFERENCE_DESC = " Hedin, A.E., H.B. Niemann, W.T. Kasprzak and A. Seiff, Global Empirical Model of the Venus Thermosphere, Journal of Geophysical Research, vol. 88, 73-83, 1983." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. SEIFF" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = "HOEGYETAL1990" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1990 REFERENCE_DESC = " Hoegy, W.R., L.H. Brace, W.T. Kasprzak and C.T. Russell, Small-Scale Plasma, Magnetic, and Neutral Density Fluctuations in the Nightside of Venus Ionosphere, Journal of Geophysical Research, vol. 95, 4085-4102, 1990. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WALTER R. HOEGY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LARRY H. BRACE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "CHRISTOPHER T. RUSSELL" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KARETAL1990 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1990 REFERENCE_DESC = " Kar, J., R. Paul, R. Kohli, K.K. Mahajan, W.T. Kasprzak and H.B. Niemann, On the Response of Exospheric Temperature on Venus to Solar Wind Conditions, Submitted to Journal of Geophysical Research, Oct. 1990." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. KAR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. PAUL" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. KOHLI" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "K. K. MAHAJAN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1980 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = "GEOPHYSICAL RESEARCH LETTERS" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Kasprzak, W.T., A.E. Hedin, H.B. Niemann and N.W. Spencer, Atomic Nitrogen in the Upper Atmosphere of Venus, Geophysical Research Letters, vol. 7,106-108, 1980. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N. W. SPENCER" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1982 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOSPHERE" JOURNAL_NAME = "PLANETARY SPACE SCIENCES" PUBLICATION_DATE = 1982 REFERENCE_DESC = " Kasprzak. W.T., H.A. Taylor, L.H. Brace and H.B. Niemann, Observations of Energetic Ions Near the Venus Ionopause, Planetary Space Sciences, vol. 30, 1107-1115, 1982. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "HARRY A. TAYLOR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LARRY H. BRACE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1987 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOTAIL" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1987 REFERENCE_DESC = " Kasprzak, W.T., H.B. Niemann and P. Mahaffy, Observations of Energetic Ions on the Nightside of Venus, Journal of Geophysical Research, vol. 32, 291-298, 1987. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "P. MAHAFFY" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1988A OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOSPHERE" JOURNAL_NAME = "NASA TECHNICAL MEMORANDUM 100717" PUBLICATION_DATE = 1988 REFERENCE_DESC = " Kasprzak, W.T. and H.B. Niemann, Fast O+ Ion Flow Observed Around Venus at Low Altitudes, NASA Technical Memorandum 100717, December 1988. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1988B OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1988 REFERENCE_DESC = " Kasprzak, W.T., A.E. Hedin, H.G. Mayr and H.B. Niemann, Wavelike Perturbations Observed in the Neutral Thermosphere of Venus, Journal of Geophysical Research, vol. 93, 11237-11245, 1988. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. G. MAYR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAK1990 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS" JOURNAL_NAME = "NASA TECHNICAL MEMORANDUM 100761" PUBLICATION_DATE = 1990 REFERENCE_DESC = " Kasprzak, W.T., The Pioneer Venus Orbiter: 11 Years of Data, NASA Technical Memorandum 100761, May 1990. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1991 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOTAIL" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1991 REFERENCE_DESC = " Kasprzak, W.T., J.M. Grebowsky, H.B. Niemann and L.H. Brace, Superthermal > 36 eV Ions Observed in the Near Tail Region of Venus by the Pioneer Venus Orbiter Neutral Mass Spectrometer, Accepted for publication in JGR, 1991." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. M. GREBOWSKY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LARRY H. BRACE" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAK&NIEMANN1991 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOSPHERE" JOURNAL_NAME = "PLANET" PUBLICATION_DATE = 1991 REFERENCE_DESC = " Kasprzak, W.T. and H.B. Niemann, Evidence for Enhanced Dynamic Flow in Ionospheric Holes from the Pioneer Venus Neutral Mass Spectrometer, Planet. Sp. Sci., 40, 33-45, 1992." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KEATINGETAL1985 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = "ADVANCES IN SPACE RESEARCH" PUBLICATION_DATE = 1985 REFERENCE_DESC = " Keating, G.M., J.L. Bertaux, S.W. Bougher, T.E. Cravens, R.E. Dickenson, A.E. Hedin, V.A. Krasnopolsky, A.F. Nagy, J.Y. Nicholson, L.J. Paxton and U. von Zahn, 'Models of Venus Neutral Upper Atmosphere: Structure and Composition,' in Venus International Reference Atmosphere, ed. A. V. Kloire, V.I. Moroz and G.M. Keating, Advances in Space Research, vol. 5, 117-171, 1985. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. M. KEATING" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. L. BERTAUX" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "S. W. BOUGHER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "T. E. CRAVENS" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. DICKENSON" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "V. A. KRASNOPOLSKY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. F. NAGY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. Y. NICHOLSON" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "L. J. PAXTON" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "U. VON ZHAN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = MAHAJANETAL1990 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1990 REFERENCE_DESC = " Mahajan, K.K., W.T. Kasprzak, L.H. Brace, H.B. Niemann and W.R. Hoegy, Response of Venus Exospheric Temperature Measured by Neutral Mass Spectrometer to Solar Flux Measured by Langmuir Probe on the Pioneer Venus Orbiter, Journal of Geophysical Research, vol. 95, 1091-1095, 1990. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "K. K. MAHAJAN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LARRY H. BRACE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WALTER R. HOEGY" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = MAYRETAL1988 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1988 REFERENCE_DESC = " Mayr, H.G., I. Harris, W.T. Kasprzak, M. Dube, and F. Variosi, Gravity Waves in the Upper Atmosphere of Venus, Journal of Geophysical Research, vol. 93, 11247-11262, 1988." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. G. MAYR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "I. HARRIS" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "M. DUBE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "F. VARIOSI" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = NIEMANNETAL1979B OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = SCIENCE PUBLICATION_DATE = 1979 REFERENCE_DESC = " Niemann, H.B., R.E. Hartle, W.T. Kasprzak, N.W. Spencer, D.M. Hunten, and G.R. Carignan, Venus Upper Atmosphere Neutral Composition: Preliminary Results from the Pioneer Orbiter, Science, vol. 203, 770-772, 1979. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. HARTLE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N.W. SPENCER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. R. CARIGAN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = NIEMANNETAL1979C OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = SCIENCE PUBLICATION_DATE = 1979 REFERENCE_DESC = " Niemann, H.B., R.E. Hartle, A.E. Hedin, W.T. Kasprzak, N.W. Spencer, D.M. Hunten and G.R. Carignan, Venus Upper Atmosphere Neutral Gas Composition: First Observations of the Diurnal Variations, Science, vol. 205, 54-56, 1979. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. HARTLE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N. W. SPENCER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. R. CARIGAN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = NIEMANNETAL1980A OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Niemann, H.B., W.T. Kasprzak, A.E. Hedin, D.M. Hunten and N.W. Spencer, Mass Spectrometric Measurements of the Neutral Gas Composition of the Thermosphere and Exosphere of Venus, Journal of Geophysical Research, vol. 85, 7817-7827, 1980a. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N. W. SPENCER" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = NIEMANNETAL1980B OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "SPECTROMETRY" JOURNAL_NAME = "IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Niemann, H.B., J.R. Booth, J.E. Cooley, R.E. Hartle, W.T. Kasprzak, N.W. Spencer, S.H. Way, D.M. Hunten and G.R. Carignan, Pioneer Venus Orbiter Neutral Gas Mass Spectrometer, IEEE Trans. on Geoscience and Remote Sensing, vol. GE-18 (1), 60-65, 1980b. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. R. BOOTH" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. E. COOLEY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. HARTLE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N. W. SPENCER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "S. H. WAY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. R. CARIGAN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = "NIEMANN&KASPRZAK1983" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "SPECTROMETRY" JOURNAL_NAME = "ADVANCES IN SPACE RESEARCH" PUBLICATION_DATE = 1983 REFERENCE_DESC = " Niemann, H.B. and W.T. Kasprzak, Comparative Neutral Composition Instrumentation and New Results, Advances in Space Research, vol. 2, 261-270, 1983. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = VONZHANETAL1983 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = VENUS PUBLICATION_DATE = 1983 REFERENCE_DESC = " von Zahn, U., S. Kumar, H. Niemann, and R. Prinn, 'Composition of the Venus Atmosphere,' in VENUS, 288-430, University of Arizona Press, Tucson, Ariz., 1983." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "U. von Zhan" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "S. Kumar" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. PRINN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO END_OBJECT = SCDATASET /************* ONMS Superthermal High Res Dataset Template ********************/ /* Modifications: */ /* 930414 -- EFRIED */ /* updated Data Set templates according to new std. */ /* Data Set Template -> Spacecraft Data Set Template */ /* event_start_time, event_stop_time -> start_time, stop_time */ /* */ /* Template: Spacecraft Data Set Template Rev: 19890121 */ /* */ /* Note: The following templates form part of a standard set */ /* for the submission of a single dataset to the PDS. */ /* */ /* Hierarchy: SCDATASET */ /* DATASETINFO */ /* DATASETTARG */ /* DSPARMINFO */ /* SCDSHOST */ /* DSREFINFO */ /* REFERENCE */ /* REFAUTHORS */ OBJECT = SCDATASET DATA_SET_ID = "PVO-V-ONMS-3-SUPERTHRMLOXYGN-HIRES-V1.0" OBJECT = DATASETINFO DATA_SET_NAME = "PVO VENUS ONMS CALIBRATED SUPERTHERMAL OXYGEN HIGH RES. V1.0" DATA_SET_COLLECTION_MEMBER_FLG = N START_TIME = 1978-12-05T15:07:07.496Z STOP_TIME = 1992-07-20T00:22:49.919Z NATIVE_START_TIME = UNK NATIVE_STOP_TIME = UNK DATA_OBJECT_TYPE = "TIME SERIES" DATA_SET_RELEASE_DATE = 1993-03-31 PROCESSING_LEVEL_ID = 3 PRODUCER_FULL_NAME = "DR. WAYNE KASPRZAK" PRODUCER_INSTITUTION_NAME = "GODDARD SPACE FLIGHT CENTER" SOFTWARE_FLAG = Y DETAILED_CATALOG_FLAG = N PROCESSING_START_TIME = UNK PROCESSING_STOP_TIME = UNK DATA_SET_DESC =" This dataset has one point for each point measured, that went into a successful data fitting for that time interval. The individual flux and density values are computed by dividing each data value by the value of the fitting function at the corresponding time. The instrument has detected superthermal, energetic or fast ions whose energy exceeds 36 eV in the spacecraft frame of reference. These ions were observed in early orbits during measurements of the neutral density near periapsis, have an erratic and unpredictable signature, and occur at too high an altitude to be due to the neutral atmosphere. When the altitude of periapsis increased above the point where sensible neutral density measurements could be made, the instrument was configured specifically to detect superthermal ions. In general, for orbit numbers 1 to 645, data were taken from the RPA mode. The gas background signal with the filament on is about a factor of 10 less in this mode than in non-RPA mode, resulting in a lower detection threshold. For orbit numbers above 923, the instrument was deliberately configured with the filament off and non-RPA mode data was used. For mass 16 the RPA voltage is about +3.8 volts. The data reduction process has been described in Kasprzak et al. (1987). The method used to reduce the data assumes cylindrical symmetry of the ion source. In actual fact, the source is asymmetrical in its angular response (Guenther, 1989). This can introduce as much as a factor of 2 scatter in the data. No simple solution has been found for modeling this asymmetry since the actual ion drift vector is unknown. The minimum energy of an ion detectable by the ONMS in this ion mode is 35.9 eV. The maximum transmission is assumed to occur about 10 V above this value. On the nightside of Venus the spacecraft potential is negative and the most probable ion energy is near 40 eV. The ion species regularly monitored include: He+, N+, O+, (N+ + CO+), and CO2+. Because of the paucity of data at other mass numbers only mass 16 (atomic oxygen) has been reduced to a flux and number density. As part of the reduction process the angle in the ecliptic plane of the apparent ion flow in spacecraft reference frame has been deduced. The flux values are estimated in the spacecraft reference frame relative to spacecraft ground. The density is computed from the flux by dividing it by a speed corresponding to 40 eV. No correction has been applied to the angle, density or flux in order to remove the effect of spacecraft velocity. Several parameters result from the fit: 1) the best estimate of the flux for the interval (used to generate the low resolution (LORES) data set); 2) the phase shift of signal maximum with respect to that predicted by the position of the velocity vector and its error; 3) the fitting parameter B (Kasprzak et al., 1987); and 4) the effective angle of attack. Other items can be derived from this data: 1) the apparent direction of the ion flow projected into the ecliptic plane; and 2) one component of the ion drift perpendicular to the plane of axis of the ONMS and the spin axis. The phase angle is negative if the predicted signal maximum from the spacecraft velocity is ahead of the true signal maximum when viewed along the -Z spacecraft axis with clockwise rotation. The drift component is derived from the condition that the total relative velocity in the moving reference frame has no component perpendicular to the (ONMS axis, Z axis) plane. The dataset fields are: YEAR YY=2 digit year (e.g. 78 for 1978) DOY DDD=3 digit day of year (e.g. 053) UT Universal time represented as the number of milliseconds since 1966-01-01T00:00:00Z stored as a double precision floating point number. ORBIT Orbit number MS Mass number - 16 for O F Flag - D single data point flux, density A fitted parameters for interval DENSITY Effective number density assuming a 40 eV ion (particles/cm{3}) FLUX Flux (particles/cm{2}/s) AZ ANG Azimuth angle of apparent ion flow direction projected into the ecliptic plane (deg) PHASE Phase shift of signal maximum with respect to that predicted by velocity vector (deg) ERROR Error in phase shift (deg) ANGATK Effective angle of attack (deg) WP DIR Direction of drift component perpendicular to (ONMS axis, Z axis) projected into the ecliptic plane (deg) WP XY Magnitude of drift component (m/s) B Fitting parameter Kasprzak, W.T., H.B. Niemann and P. Mahaffy, Observations of Energetic Ions on the Nightside of Venus, Journal of Geophysical Research, vol. 32, 291-298, 1987. " /* */ /******************************************************************************/ /* */ CONFIDENCE_LEVEL_NOTE = " In order to fit the data a minimum of 30 points were required in 36 seconds. In addition, the maximum to minimum count ratio was required to be factor of 3 or greater in order to insure that there was a definitive spin modulation. The center 12 seconds of data is divided by the fitting function to derive the equivalent flux for that point. The center of the new fitting interval is adjusted so that it is centered on the expected signal maximum predicted from the previous interval fit. As a result of this method of fitting, discontinuities may exist near minimum angle of attack where one 12 second interval adjoins the next interval. See Kasprzak et al. (1987). Kasprzak, W.T., H.B. Niemann and P. Mahaffy, Observations of Energetic Ions on the Nightside of Venus, Journal of Geophysical Research, vol. 32, 291-298, 1987. " END_OBJECT = DATASETINFO /* */ /******************************************************************************/ /* */ OBJECT = DATASETTARG TARGET_NAME = VENUS END_OBJECT = DATASETTARG OBJECT = DSPARMINFO SAMPLING_PARAMETER_NAME = TIME SAMPLING_PARAMETER_RESOLUTION = UNK MINIMUM_SAMPLING_PARAMETER = "N/A" MAXIMUM_SAMPLING_PARAMETER = "N/A" SAMPLING_PARAMETER_INTERVAL = "N/A" MINIMUM_AVAILABLE_SAMPLING_INT = UNK SAMPLING_PARAMETER_UNIT = SECOND DATA_SET_PARAMETER_NAME = "ION DENSITY" NOISE_LEVEL = UNK DATA_SET_PARAMETER_UNIT = "PARTICLES/CM**3" /* SAMPLING_DESCRIPTION = " */ /* This dataset has one point for each point measured, that went */ /* into a successful data fitting for that time interval. The individual */ /* flux and density values are computed by dividing each data value by */ /* the value of the fitting function at the corresponding time." */ END_OBJECT = DSPARMINFO OBJECT = DSPARMINFO SAMPLING_PARAMETER_NAME = TIME SAMPLING_PARAMETER_RESOLUTION = UNK MINIMUM_SAMPLING_PARAMETER = "N/A" MAXIMUM_SAMPLING_PARAMETER = "N/A" SAMPLING_PARAMETER_INTERVAL = "N/A" MINIMUM_AVAILABLE_SAMPLING_INT = UNK SAMPLING_PARAMETER_UNIT = SECOND DATA_SET_PARAMETER_NAME = "ION FLUX" NOISE_LEVEL = UNK DATA_SET_PARAMETER_UNIT = "PARTICLES/(CM**2 * SECOND)" END_OBJECT = DSPARMINFO OBJECT = SCDSHOST INSTRUMENT_HOST_ID = PVO INSTRUMENT_ID = ONMS END_OBJECT = SCDSHOST /* */ /******************************************************************************/ /* */ OBJECT = DSREFINFO REFERENCE_KEY_ID = BRACEETAL1987 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOTAIL" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1987 REFERENCE_DESC = " Brace, L.H., W.T. Kasprzak, H.A. Taylor, R.F. Theis, C.T. Russell, A. Barnes, J.D. Mihalov and D.M. Hunten, The Ionotail of Venus: Its Configuration and Evidence for Ion Escape, J. of Geophys. Res, vol 92, 15-26, 1987. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LARRY H. BRACE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "HARRY A. TAYLOR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "ROBERT F. THEIS" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "CHRISTOPHER T. RUSSELL" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "AARON BARNES" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. D. MIHALOV" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = GUENTHER1989 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "PLASMA INSTRUMENTS" JOURNAL_NAME = UNK PUBLICATION_DATE = 1989 REFERENCE_DESC = " Guenther, Y.P., 'Pioneer Venus Neutral Mass Spectrometer,' NASA/Goddard Space Flight Center Summer Institute on Atmospheric Science, Laboratory for Planetary Atmospheres, Code 910, 1989. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "Y. P. GUENTHER" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = HEDINETAL1983 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1983 REFERENCE_DESC = " Hedin, A.E., H.B. Niemann, W.T. Kasprzak and A. Seiff, Global Empirical Model of the Venus Thermosphere, Journal of Geophysical Research, vol. 88, 73-83, 1983." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. SEIFF" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = "HOEGYETAL1990" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1990 REFERENCE_DESC = " Hoegy, W.R., L.H. Brace, W.T. Kasprzak and C.T. Russell, Small-Scale Plasma, Magnetic, and Neutral Density Fluctuations in the Nightside of Venus Ionosphere, Journal of Geophysical Research, vol. 95, 4085-4102, 1990. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WALTER R. HOEGY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LARRY H. BRACE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "CHRISTOPHER T. RUSSELL" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KARETAL1990 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUE THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1990 REFERENCE_DESC = " Kar, J., R. Paul, R. Kohli, K.K. Mahajan, W.T. Kasprzak and H.B. Niemann, On the Response of Exospheric Temperature on Venus to Solar Wind Conditions, Submitted to Journal of Geophysical Research, Oct. 1990." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. KAR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. PAUL" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. KOHLI" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "K. K. MAHAJAN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1980 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = "Geophysical Research Letters" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Kasprzak, W.T., A.E. Hedin, H.B. Niemann and N.W. Spencer, Atomic Nitrogen in the Upper Atmosphere of Venus, Geophysical Research Letters, vol. 7,106-108, 1980. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N. W. SPENCER" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1982 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOSPHERE" JOURNAL_NAME = "PLANETARY SPACE SCIENCES" PUBLICATION_DATE = 1982 REFERENCE_DESC = " Kasprzak. W.T., H.A. Taylor, L.H. Brace and H.B. Niemann, Observations of Energetic Ions Near the Venus Ionopause, Planetary Space Sciences, vol. 30, 1107-1115, 1982. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "HARRY A. TAYLOR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LARRY H. BRACE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1987 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOTAIL" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1987 REFERENCE_DESC = " Kasprzak, W.T., H.B. Niemann and P. Mahaffy, Observations of Energetic Ions on the Nightside of Venus, Journal of Geophysical Research, vol. 32, 291-298, 1987. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "P. MAHAFFY" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAK&NIEMANN1988 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOSPHERE" JOURNAL_NAME = "NASA Technical Memorandum 100717" PUBLICATION_DATE = 1988 REFERENCE_DESC = " Kasprzak, W.T. and H.B. Niemann, Fast O+ Ion Flow Observed Around Venus at Low Altitudes, NASA Technical Memorandum 100717, December 1988. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAK&NIEMANN1988 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1988 REFERENCE_DESC = " Kasprzak, W.T., A.E. Hedin, H.G. Mayr and H.B. Niemann, Wavelike Perturbations Observed in the Neutral Thermosphere of Venus, Journal of Geophysical Research, vol. 93, 11237-11245, 1988. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. G. MAYR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAK1990 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS" JOURNAL_NAME = "NASA Technical Memorandum 100761" PUBLICATION_DATE = 1990 REFERENCE_DESC = " Kasprzak, W.T., The Pioneer Venus Orbiter: 11 Years of Data, NASA Technical Memorandum 100761, May 1990. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAKETAL1991 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOTAIL" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1991 REFERENCE_DESC = " Kasprzak, W.T., J.M. Grebowsky, H.B. Niemann and L.H. Brace, Superthermal > 36 eV Ions Observed in the Near Tail Region of Venus by the Pioneer Venus Orbiter Neutral Mass Spectrometer, Accepted for publication in JGR, 1991." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. M. GREBOWSKY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LARRY H. BRACE" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KASPRZAK&NIEMANN1991 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOSPHERE" JOURNAL_NAME = "PLANET" PUBLICATION_DATE = 1991 REFERENCE_DESC = " Kasprzak, W.T. and H.B. Niemann, Evidence for Enhanced Dynamic Flow in Ionospheric Holes from the Pioneer Venus Neutral Mass Spectrometer, Planet. Sp. Sci., 40, 33-45, 1992." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = KEATINGETAL1985 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = "ADVANCES IN SPACE RESEARCH" PUBLICATION_DATE = 1985 REFERENCE_DESC = " Keating, G.M., J.L. Bertaux, S.W. Bougher, T.E. Cravens, R.E. Dickenson, A.E. Hedin, V.A. Krasnopolsky, A.F. Nagy, J.Y. Nicholson, L.J. Paxton and U. von Zahn, 'Models of Venus Neutral Upper Atmosphere: Structure and Composition,' in Venus International Reference Atmosphere, ed. A. V. Kloire, V.I. Moroz and G.M. Keating, Advances in Space Research, vol. 5, 117-171, 1985. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. M. KEATING" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. L. BERTAUX" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "S. W. BOUGHER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "T. E. CRAVENS" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. DICKENSON" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "V. A. KRASNOPOLSKY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. F. NAGY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. Y. NICHOLSON" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "L. J. PAXTON" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "U. VON ZHAN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = MAHAJANETAL1990 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1990 REFERENCE_DESC = " Mahajan, K.K., W.T. Kasprzak, L.H. Brace, H.B. Niemann and W.R. Hoegy, Response of Venus Exospheric Temperature Measured by Neutral Mass Spectrometer to Solar Flux Measured by Langmuir Probe on the Pioneer Venus Orbiter, Journal of Geophysical Research, vol. 95, 1091-1095, 1990. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "K. K. MAHAJAN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "LARRY H. BRACE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WALTER R. HOEGY" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = MAYRETAL1988 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1988 REFERENCE_DESC = " Mayr, H.G., I. Harris, W.T. Kasprzak, M. Dube, and F. Variosi, Gravity Waves in the Upper Atmosphere of Venus, Journal of Geophysical Research, vol. 93, 11247-11262, 1988." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. G. MAYR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "I. HARRIS" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "M. DUBE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "F. VARIOSI" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = NIEMANNETAL1979B OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = SCIENCE PUBLICATION_DATE = 1979 REFERENCE_DESC = " Niemann, H.B., R.E. Hartle, W.T. Kasprzak, N.W. Spencer, D.M. Hunten, and G.R. Carignan, Venus Upper Atmosphere Neutral Composition: Preliminary Results from the Pioneer Orbiter, Science, vol. 203, 770-772, 1979. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. HARTLE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N.W. SPENCER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. R. CARIGAN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = NIEMANNETAL1979C OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = SCIENCE PUBLICATION_DATE = 1979 REFERENCE_DESC = " Niemann, H.B., R.E. Hartle, A.E. Hedin, W.T. Kasprzak, N.W. Spencer, D.M. Hunten and G.R. Carignan, Venus Upper Atmosphere Neutral Gas Composition: First Observations of the Diurnal Variations, Science, vol. 205, 54-56, 1979. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. HARTLE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N. W. SPENCER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. R. CARIGAN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = NIEMANNETAL1980A OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS THERMOSPHERE" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Niemann, H.B., W.T. Kasprzak, A.E. Hedin, D.M. Hunten and N.W. Spencer, Mass Spectrometric Measurements of the Neutral Gas Composition of the Thermosphere and Exosphere of Venus, Journal of Geophysical Research, vol. 85, 7817-7827, 1980a. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "A. E. HEDIN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N. W. SPENCER" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = NIEMANNETAL1980B OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "SPECTROMETRY" JOURNAL_NAME = "IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING" PUBLICATION_DATE = 1980 REFERENCE_DESC = " Niemann, H.B., J.R. Booth, J.E. Cooley, R.E. Hartle, W.T. Kasprzak, N.W. Spencer, S.H. Way, D.M. Hunten and G.R. Carignan, Pioneer Venus Orbiter Neutral Gas Mass Spectrometer, IEEE Trans. on Geoscience and Remote Sensing, vol. GE-18 (1), 60-65, 1980b. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. R. BOOTH" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "J. E. COOLEY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. E. HARTLE" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "N. W. SPENCER" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "S. H. WAY" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "D. M. HUNTEN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "G. R. CARIGAN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = "NIEMANN&KASPRZAK1983" OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "SPECTROMETRY" JOURNAL_NAME = "ADVANCES IN SPACE RESEARCH" PUBLICATION_DATE = 1983 REFERENCE_DESC = " Niemann, H.B. and W.T. Kasprzak, Comparative Neutral Composition Instrumentation and New Results, Advances in Space Research, vol. 2, 261-270, 1983. " OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO OBJECT = DSREFINFO REFERENCE_KEY_ID = VONZHANETAL1983 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS ATMOSPHERE" JOURNAL_NAME = VENUS PUBLICATION_DATE = 1983 REFERENCE_DESC = " von Zahn, U., S. Kumar, H. B. Niemann, and R. Prinn, 'Composition of the Venus Atmosphere,' in VENUS, 288-430, University of Arizona Press, Tucson, Ariz., 1983." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "U. von Zhan" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "S. Kumar" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "R. PRINN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO END_OBJECT = SCDATASET /********** ONMS ION Dataset Template *****************************************/ /* Modifications: */ /* 930414 -- EFRIED */ /* updated Data Set templates according to new std. */ /* Data Set Template -> Spacecraft Data Set Template */ /* event_start_time, event_stop_time -> start_time, stop_time */ /* */ /* Template: Data Set Template Rev: 19890121 */ /* */ /* Note: The following templates form part of a standard set */ /* for the submission of a single dataset to the PDS. */ /* */ /* Hierarchy: SCDATASET */ /* DATASETINFO */ /* DATASETTARG */ /* DSPARMINFO */ /* SCDSHOST */ /* DSREFINFO */ /* REFERENCE */ /* REFAUTHORS */ OBJECT = SCDATASET DATA_SET_ID = "PVO-V-ONMS-4-THERMAL-ION-12SEC-V1.0" OBJECT = DATASETINFO DATA_SET_NAME = "PVO VENUS ONMS BROWSE THERMAL ION 12 SECOND V1.0" DATA_SET_COLLECTION_MEMBER_FLG = N START_TIME = 1980-03-15T10:26:29.656Z STOP_TIME = 1992-09-25T23:09:39.859Z NATIVE_START_TIME = UNK NATIVE_STOP_TIME = UNK DATA_OBJECT_TYPE = "TIME SERIES" DATA_SET_RELEASE_DATE = 1993-03-31 PROCESSING_LEVEL_ID = 4 PRODUCER_FULL_NAME = "DR. WAYNE KASPRZAK" PRODUCER_INSTITUTION_NAME = "GODDARD SPACE FLIGHT CENTER" SOFTWARE_FLAG = Y DETAILED_CATALOG_FLAG = N PROCESSING_START_TIME = UNK PROCESSING_STOP_TIME = UNK DATA_SET_DESC =" Thermal ions can be measured with the filament off and the ion repeller set at 0 V. Species observed include He+, N+, O+, CO+ and/or N2+, NO+, O2+ and CO2+. H+ is not measurable with the current instrument configuration. One component of the ion drift in the ecliptic plane can also be determined. Thermal ion measurements have been taken sporadically at the end of neutral density passes and on alternate orbits when superthermal ions are not being measured. The ONMS instrument was not operated on all orbits and some orbits are devoted to engineering studies. Typically neutral density passes occupied -40 min. to +30 min. relative to the time of periapsis. Ion and superthermal ion mode passes typically are 15 to 20 minutes in duration on either side of periapsis. Neutral density passes during entry also took about this same amount of time. The data values of the data set are sampled approximately once per 12 seconds based on GMT times that have been supplied by the Pioneer Venus Project. Each representative data point is constructed using an exponentially weighted average of the data over a 24 second interval centered at sample point time. The data have the following characteristics: LOGICAL RECORD SIZE: 80 bytes FORMAT: ASCII FILES: 1 The field names used in RECORD 1: VARIABLE COMMENT DATE YYDDD YY=2 digit year (e.g. 78 for 1978) DDD=3 digit day of year (e.g. 053) UT Universal Time represented as the number of milliseconds since 1966-01-01T00:00:00Z stored as a double precision floating point number. ORBIT Orbit number PSEC Time after periapsis (sec) DENS Density in particles/cm**3 WPXY Minimum ion drift m/sec PHSE Phase shift (degrees) MASS Mass number - 4 for He+ 12 for C+ 14 for N+ 16 for O+ 28 for N2+ and/or CO+ 30 for NO+ 32 for O2+ 44 for CO2+ VALT Altitude above the mean surface of Venus in km VLAT Venus latitude in degrees VLST Venus local solar time in hr VSZA Venus solar zenith angle in degrees The relationship between thermal ion density and instrument output was established by direct comparison of the O+ signal with the O+ density determined from the Orbiter Ion Mass Spectrometer (OIMS) instrument using O+ data from orbit number 530 at 300 seconds from periapsis. Other species are assumed to have the same sensitivity as that of O+. In this mode superthermal ions cannot be distinguished from thermal ions. The data reduction process has been described in Kasprzak et al. (1992) but was similar to the technique used for the Superthermal O+ ion data. In order to fit the superthermal O+ data, a minimum of 30 points were required in 36 seconds. In addition, the maximum to minimum count ratio was required to be factor of 3 or greater in order to insure that there was a definitive spin modulation. The center 12 seconds of data is divided by the fitting function to derive the equivalent flux for that point. The center of the new fitting interval is adjusted so that it is centered on the expected signal maximum predicted from the previous interval fit. As a result of this method of fitting, discontinuities may exist near minimum angle of attack where one 12 second interval adjoins the next interval. The method used to reduce the data assumes cylindrical symmetry of the ion source. In actual fact, the source is asymmetrical in its angular response (Guenther, 1989). This can introduce as much as a factor of 2 scatter in the data. The ion species regularly monitored include: He+, N+, O+, N2+ and/or CO+, NO+ and CO2+. As part of the reduction process the minimum ion drift in the ecliptic plane of the apparent ion flow in spacecraft reference frame has been deduced. The density is computed by assuming the ions are thermal energy with a speed equivalent to that of the spacecraft. An approximate correction for spacecraft potential has been applied. The data are normalized to the OIMS instrument for O+ and all species are assumed to have the same sensitivity. Several parameters result from the fit: 1) the best estimate of the density for an approximate 12 second interval (LORES data set); and 2) the phase shift of signal maximum; and 3) the minimum ion drift speed in the ecliptic plane. The phase angle is negative if the predicted signal maximum from the spacecraft velocity is ahead of the true signal maximum when viewed along the -Z spacecraft axis with clockwise rotation. The drift component is derived from the condition that the total relative velocity in the moving reference frame has no component perpendicular to the (ONMS axis, Z axis) plane. All data were processed at NASA/Goddard Space Flight Center using custom programmed software. The software is available. The data represent a reduction to physical units (density, flux) and were processed from an intermediate engineering unit file (current, count/sec etc.). Unit and 1/8 unit amu sweeps are not contained in the processed data sets but are available from the engineering unit data set. The engineering unit data is converted to ambient values using spacecraft velocity and attitude, the theoretical expected system response, and the corresponding calibration factors. Superthermal ion data for species other than O+ is available in engineering unit form. Kasprzak, W.T. and H.B. Niemann, Evidence for Enhanced Dynamic Flow in Ionospheric Holes from the Pioneer Venus Neutral Mass Planetary Space Sciences, 40, 33-45,1992." /* */ /******************************************************************************/ /* */ CONFIDENCE_LEVEL_NOTE = " In order to fit the data a minimum of 30 points were required in 36 seconds. In addition, the maximum to minimum count ratio was required to be factor of 3 or greater in order to insure that there was a definitive spin modulation. The center 12 seconds of data is divided by the fitting function to derive the equivalent flux for that point. The center of the new fitting interval is adjusted so that it is centered on the expected signal maximum predicted from the previous interval fit. As a result of this method of fitting, discontinuities may exist near minimum angle of attack where one 12 second interval adjoins the next interval. See Kasprzak et al. (1992). Kasprzak, W.T. and H.B. Niemann, Evidence for Enhanced Dynamic Flow in Ionospheric Holes from the Pioneer Venus Neutral Mass Planetary Space Sciences, 40, 33-45,1992." END_OBJECT = DATASETINFO /* */ /******************************************************************************/ /* */ OBJECT = DATASETTARG TARGET_NAME = VENUS END_OBJECT = DATASETTARG OBJECT = DSPARMINFO SAMPLING_PARAMETER_NAME = TIME SAMPLING_PARAMETER_RESOLUTION = 12.0 MINIMUM_SAMPLING_PARAMETER = "N/A" MAXIMUM_SAMPLING_PARAMETER = "N/A" SAMPLING_PARAMETER_INTERVAL = 12.0 MINIMUM_AVAILABLE_SAMPLING_INT = 12.0 SAMPLING_PARAMETER_UNIT = SECOND DATA_SET_PARAMETER_NAME = "ION RATE" NOISE_LEVEL = UNK DATA_SET_PARAMETER_UNIT = "PARTICLES/SECOND" /* SAMPLING_PARAMETER_DESC = " /* This data set represents the maximum count rate per second in a /* 12 second period beginning with the time of the first data point for /* a given mass number." END_OBJECT = DSPARMINFO OBJECT = SCDSHOST INSTRUMENT_HOST_ID = PVO INSTRUMENT_ID = ONMS END_OBJECT = SCDSHOST /* */ /******************************************************************************/ /* */ OBJECT = DSREFINFO REFERENCE_KEY_ID = BRACEETAL1987 OBJECT = REFERENCE DOCUMENT_TOPIC_TYPE = "VENUS IONOTAIL" JOURNAL_NAME = "JOURNAL OF GEOPHYSICAL RESEARCH" PUBLICATION_DATE = 1987 REFERENCE_DESC = " Kasprzak, W.T. and H.B. Niemann, Evidence for Enhanced Dynamic Flow in Ionospheric Holes from the Pioneer Venus Neutral Mass Planetary Space Sciences, 40, 33-45,1992." OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "WAYNE T. KASPRZAK" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "HARRY A. TAYLOR" END_OBJECT = REFAUTHORS OBJECT = REFAUTHORS AUTHOR_FULL_NAME = "H. B. NIEMANN" END_OBJECT = REFAUTHORS END_OBJECT = REFERENCE END_OBJECT = DSREFINFO END_OBJECT = SCDATASET /*********************** SC COORDS TEMPLATE ***********************************/ /* MODIFICATIONS: */ /* 930309 -- MKNIFFIN/SJOY modified with ctr and sjoy info. */ /* 930310 -- MKNIFFIN ran clean on jpl lvtool */ /* 930315 -- SJOY updated totally. */ /* 930526 -- SJOY added remaining coordinate systems for use in SEDR */ /* CD-ROM production. All PVO coordinate systems now defined. */ /* Template: Coordinate System Template Rev: 19890121 */ /* Note: The following templates form part of a standard */ /* set for the submission of a Coordinate System */ /* to the PDS. */ /* Hierarchy: COORDINATE */ /* COORDINFO */ /* VECTOR */ /* VECTORCOMP */ /* VECTORD */ /* /**************************************************************************** /* Spinning S/C Coordinates /**************************************************************************** /* OBJECT = COORDINATE COORDINATE_SYSTEM_ID = PVO_SSCC OBJECT = COORDINFO COORDINATE_SYSTEM_NAME = "PVO SPINNING SPACECRAFT COORDS" COORDINATE_SYSTEM_CENTER_NAME = PVO COORDINATE_SYSTEM_REF_EPOCH = "N/A" COORDINATE_SYSTEM_DESC = " Spacecraft coordinates (Xs, Ys, Zs) are used to describe the physical mounting locations of the Sun sensors, the star sensor, and the experiment sensors. The spacecraft coordinate system is centered at the spacecraft center of mass and rotates with the spacecraft. The Xs-Ys plane is parallel to the plane of the spacecraft equipment shelf. The positive Zs axis points out the top of the spacecraft. The positive Ys axis coincides with the split line of the equipment shelf. With no spacecraft wobble or nutation, the spacecraft positive Zs axis will coincide with the spin axis and the equipment shelf will thus be perpendicular to the spin axis." END_OBJECT = COORDINFO OBJECT = VECTOR VECTOR_COMPONENT_TYPE = SSCC_X OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = XS REFERENCE_OBJECT_NAME = "N/A" REFERENCE_TARGET_NAME = "N/A" VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " The +Xs axis of the PVO spacecraft coordinate system is defined to lie in a plane parallel to the equipment shelf at 90 degrees to the split-line of the equipment shelf measured in the direction opposing the spacecraft spin direction." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = SSCC_Y OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = YS REFERENCE_OBJECT_NAME = "N/A" REFERENCE_TARGET_NAME = SPACECRAFT VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " The +Ys axis of the PVO spacecraft coordinate system is defined to lie in a plane parallel to the equipment shelf and follow the split-line of the equipment shelf." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = SSCC_Z OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = ZS REFERENCE_OBJECT_NAME = "N/A" REFERENCE_TARGET_NAME = SPACECRAFT VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " The positive Zs axis points out the top of the spacecraft. With no spacecraft wobble or nutation, the spacecraft positive Zs axis will coincide with the spin axis and the equipment shelf will thus be perpendicular to the spin axis." END_OBJECT = VECTORD END_OBJECT = VECTOR END_OBJECT = COORDINATE /* /**************************************************************************** /* Inertial S/C Coordinates /**************************************************************************** /* OBJECT = COORDINATE COORDINATE_SYSTEM_ID = PVO_ISCC OBJECT = COORDINFO COORDINATE_SYSTEM_NAME = "PVO INERTIAL SPACECRAFT COORDS" COORDINATE_SYSTEM_CENTER_NAME = PVO COORDINATE_SYSTEM_REF_EPOCH = "UNK" /*1950.0*/ COORDINATE_SYSTEM_DESC = " The inertial spacecraft coordinate system for the PVO spacecraft is same coordinate system as the spinning spacecraft coordinate system (SSCC) except that it does not spin with the spacecraft. Thus the Spin axis or positive Z axis direction is the same in both systems and it points out the top (toward the BAFTA assembly) of the spacecraft. The axes in the spin plane are defined as follows: The X-Z plane is defined to contain the spacecraft-Sun vector with the positive X direction being sunward, and the coordinate system is defined to be right-handed. The transformation from SSCC to ISCC is: _ _ | cos(p) -sin(p) 0 | | sin(p) cos(p) 0 | | 0 0 1 | _ _ where p is the spin phase angle measured in ISSC coordinates." END_OBJECT = COORDINFO OBJECT = VECTOR VECTOR_COMPONENT_TYPE = ISCC_X OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = PVO_X REFERENCE_OBJECT_NAME = "N/A" REFERENCE_TARGET_NAME = SPACECRAFT VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " The X component of the PVO spacecraft coordinate system lies in the sunward direction, such that the X-Z plane contains the sun. The X component is measured positive towards the sun." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = ISCC_Y OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = PVO_Y REFERENCE_OBJECT_NAME = "N/A" REFERENCE_TARGET_NAME = SPACECRAFT VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " The Y component is formed by the right-handed vector cross product of the X and Z unit vectors where the Z axis is defined as the spacecraft spin axis and the X-Z plane contains the Sun." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = ISCC_Z OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = PVO_Z REFERENCE_OBJECT_NAME = "N/A" REFERENCE_TARGET_NAME = SPACECRAFT VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " The Z axis is defined to be anti-parallel to the spacecraft spin axis during orbital operations." END_OBJECT = VECTORD END_OBJECT = VECTOR END_OBJECT = COORDINATE /**************************************************************************** /* VSO Coordinates /**************************************************************************** /* MODIFICATIONS: /* 930223 -- MKNIFFIN /* created template OBJECT = COORDINATE COORDINATE_SYSTEM_ID = VSO OBJECT = COORDINFO COORDINATE_SYSTEM_NAME = "VENUS SOLAR ORBITAL COORDS" COORDINATE_SYSTEM_CENTER_NAME = "VENUS" COORDINATE_SYSTEM_REF_EPOCH = "N/A" COORDINATE_SYSTEM_DESC = " The VSO coordinate system is a Cartesian coordinate system centered on Venus. The components of this coordinate system are as follows: The X axis direction points from the center of Venus to the Sun, taken positive towards the Sun, the Z axis is parallel to the northward pole of the Venus orbital plane, the Y axis completes the right-handed set and points towards dusk. Locations of bodies (spacecraft) given in VSO coordinates are usually represented in units of Venus radii where Rv = 6052 km." END_OBJECT = COORDINFO OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = VSO_X REFERENCE_OBJECT_NAME = SUN REFERENCE_TARGET_NAME = VENUS VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " The X component of the VSO coordinate system is taken to be positive in the direction of the Sun measured along the Venus- Sun line. The units are commonly given in Venus Radii where Rv = 6052 km" END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = VSO_Y REFERENCE_OBJECT_NAME = SUN REFERENCE_TARGET_NAME = VENUS VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " The Y component of the VSO coordinate system is taken to be positive in the direction opposing orbital motion (dusk) and lying in the orbital plane of Venus. The units are commonly given in Venus Radii where Rv = 6052 km" END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = VSO_Z REFERENCE_OBJECT_NAME = SUN REFERENCE_TARGET_NAME = VENUS VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " The Z component of the VSO coordinate system is taken to be parallel to the pole of the Venus orbital plane and positive in the northward direction (upward normal). The units are commonly given in Venus Radii where Rv = 6052 km" END_OBJECT = VECTORD END_OBJECT = VECTOR END_OBJECT = COORDINATE /**************************************************************************** /* Inertial Spherical Coordinates - Equatorial /**************************************************************************** OBJECT = COORDINATE COORDINATE_SYSTEM_ID = ISC_EQTR OBJECT = COORDINFO COORDINATE_SYSTEM_NAME = "EQUATORIAL INERT SPHRCL COORDS" COORDINATE_SYSTEM_CENTER_NAME = "EARTH" COORDINATE_SYSTEM_REF_EPOCH = "UNK" /* 1950.0 */ COORDINATE_SYSTEM_DESC = " The EQUATORIAL INERTIAL SPHERICAL COORDINATE system is defined by the equatorial plane of the Earth for the reference epoch of 1950.0. The principal direction vectors of this system are the Earth's Equatorial Pole and the Vernal Equinox direction. The components of the coordinate system are: 1) Radius: Distance from the reference body to the spacecraft. 2) Declination: The angle between the reference body-spacecraft radius vector and the reference body equatorial plane, measured positive north of the equatorial plane. 3) Right Ascension: The angle between the Vernal Equinox line and the projection of the reference body-spacecraft radius vector onto the Earth equatorial plane, measured eastward from the Vernal Equinox line. 4) Inertial Speed (V): The magnitude of the inertial velocity of the spacecraft. 5) Inertial Flight Path Angle (GAMMA): The angle between the spacecraft inertial velocity vector and the plane perpendicular to the reference-body-to-spacecraft (radius) vector; positive when measured away from the reference body. 6) Inertial Azimuth Angle (SIGMA): The angle, measured in the plane perpendicular to the reference-body-to-spacecraft (radius) vector, from the projection of true north into that plane eastward to the projection of the inertial velocity vector into that plane. When the reference body is taken to be the Earth, this becomes the coordinate system EME-50. (FK-4)" END_OBJECT = COORDINFO OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = RADIUS REFERENCE_OBJECT_NAME = UNK REFERENCE_TARGET_NAME = SPACECRAFT VECTOR_COMPONENT_UNIT = "UNK" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " Radius: Distance from the reference body to the spacecraft." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = LATITUDE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = DECLNATN REFERENCE_OBJECT_NAME = UNK REFERENCE_TARGET_NAME = SPACECRAFT VECTOR_COMPONENT_UNIT = "UNK" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " Declination: The angle between the reference body-spacecraft radius vector and the reference body equatorial plane, measured positive north of the equatorial plane. " END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = LONGITUDE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = "R ASCNSN" REFERENCE_OBJECT_NAME = UNK REFERENCE_TARGET_NAME = SPACECRAFT VECTOR_COMPONENT_UNIT = "UNK" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " Right Ascension: The angle between the Vernal Equinox line and the projection of the reference body-spacecraft radius vector onto the Earth equatorial plane, measured eastward from the Vernal Equinox line." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = VELOCITY OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = "V" REFERENCE_OBJECT_NAME = UNK REFERENCE_TARGET_NAME = SPACECRAFT VECTOR_COMPONENT_UNIT = "UNK" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " Inertial Speed (V): The magnitude of the inertial velocity of the spacecraft." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = VELOCITY OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = GAMMA REFERENCE_OBJECT_NAME = UNK REFERENCE_TARGET_NAME = SPACECRAFT VECTOR_COMPONENT_UNIT = "UNK" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " Inertial Flight Path Angle (GAMMA): The angle between the spacecraft inertial velocity vector and the plane perpendicular to the reference-body-to-spacecraft (radius) vector; positive when measured away from the reference body." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = VELOCITY OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = SIGMA REFERENCE_OBJECT_NAME = UNK REFERENCE_TARGET_NAME = SPACECRAFT VECTOR_COMPONENT_UNIT = "UNK" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " Inertial Azimuth Angle (SIGMA): The angle, measured in the plane perpendicular to the reference-body-to-spacecraft (radius) vector, from the projection of true north into that plane eastward to the projection of the inertial velocity vector into that plane. " END_OBJECT = VECTORD END_OBJECT = VECTOR END_OBJECT = COORDINATE /**************************************************************************** /* Inertial Spherical Coordinates - Ecliptic /**************************************************************************** OBJECT = COORDINATE COORDINATE_SYSTEM_ID = ISC_ECLP OBJECT = COORDINFO COORDINATE_SYSTEM_NAME = "ECLIPTIC INERTL SPHERCL COORDS" COORDINATE_SYSTEM_CENTER_NAME = "EARTH" COORDINATE_SYSTEM_REF_EPOCH = "UNK" /* 1950.0 */ COORDINATE_SYSTEM_DESC = " The ECLIPTIC INERTIAL SPHERICAL COORDINATE system is defined by the ecliptic plane of the Earth for the reference epoch of 1950.0. The principal direction vectors of this system are the Earth's Ecliptic Pole and the Vernal Equinox direction. The components of the coordinate system are: 1) Radius: Distance from the reference body to the spacecraft. 2) Celestial Latitude: The angle between the reference body-spacecraft radius vector and the reference body ecliptic plane, measured positive north of the ecliptic plane. 3) Celestial Longitude: The angle between the Vernal Equinox line and the projection of the reference body-spacecraft radius vector onto the Earth ecliptic plane, measured eastward from the Vernal Equinox line. 4) Inertial Speed (V): The magnitude of the inertial velocity of the spacecraft. 5) Inertial Flight Path Angle (GAMMA): The angle between the spacecraft inertial velocity vector and the plane perpendicular to the reference-body-to-spacecraft (radius) vector; positive when measured away from the reference body. 6) Inertial Azimuth Angle (SIGMA): The angle, measured in the plane perpendicular to the reference-body-to-spacecraft (radius) vector, from the projection of true north into that plane eastward to the projection of the inertial velocity vector into that plane. When the reference body is taken to be the Earth, this becomes the coordinate system ECL-50." END_OBJECT = COORDINFO OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = RADIUS REFERENCE_OBJECT_NAME = UNK REFERENCE_TARGET_NAME = SPACECRAFT VECTOR_COMPONENT_UNIT = "UNK" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " Radius: Distance from the reference body to the spacecraft." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = LATITUDE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = "CLST LAT" REFERENCE_OBJECT_NAME = UNK REFERENCE_TARGET_NAME = SPACECRAFT VECTOR_COMPONENT_UNIT = "UNK" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " Celestial Latitude: The angle between the reference body-spacecraft radius vector and the reference body ecliptic plane, measured positive north of the ecliptic plane. " END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = LONGITUDE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = "CLST LNG" REFERENCE_OBJECT_NAME = UNK REFERENCE_TARGET_NAME = SPACECRAFT VECTOR_COMPONENT_UNIT = "UNK" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " Celestial Longitude: The angle between the Vernal Equinox line and the projection of the reference body-spacecraft radius vector onto the ecliptic plane, measured eastward from the Vernal Equinox line." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = VELOCITY OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = "V" REFERENCE_OBJECT_NAME = UNK REFERENCE_TARGET_NAME = SPACECRAFT VECTOR_COMPONENT_UNIT = "UNK" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " Inertial Speed (V): The magnitude of the inertial velocity of the spacecraft." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = VELOCITY OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = GAMMA REFERENCE_OBJECT_NAME = UNK REFERENCE_TARGET_NAME = SPACECRAFT VECTOR_COMPONENT_UNIT = "UNK" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " Inertial Flight Path Angle (GAMMA): The angle between the spacecraft inertial velocity vector and the plane perpendicular to the reference-body-to-spacecraft (radius) vector; positive when measured away from the reference body." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = VELOCITY OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = SIGMA REFERENCE_OBJECT_NAME = UNK REFERENCE_TARGET_NAME = SPACECRAFT VECTOR_COMPONENT_UNIT = "UNK" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " Inertial Azimuth Angle (SIGMA): The angle, measured in the plane perpendicular to the reference-body-to-spacecraft (radius) vector, from the projection of true north into that plane eastward to the projection of the inertial velocity vector into that plane." END_OBJECT = VECTORD END_OBJECT = VECTOR END_OBJECT = COORDINATE /**************************************************************************** /* Earth-Sun Line Cartesian Coordinates /**************************************************************************** OBJECT = COORDINATE COORDINATE_SYSTEM_ID = "ESL-CART" OBJECT = COORDINFO COORDINATE_SYSTEM_NAME = "EARTH-SUN LINE CARTES COORDS" COORDINATE_SYSTEM_CENTER_NAME = SUN COORDINATE_SYSTEM_REF_EPOCH = "N/A" COORDINATE_SYSTEM_DESC = " The Earth-Sun Line Cartesian coordinate system is defined to have the X-Y plane be the instantaneous ecliptic plane with the positive Z direction taken to be the Sun-centered, northward ecliptic normal. The positive X direction is away from the Sun along the Sun-Earth line. Y completes the right-handed set and is positive away from the Sun. Note: This system rotates with the Earth about the Sun." END_OBJECT = COORDINFO OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = ESL_X REFERENCE_OBJECT_NAME = SUN REFERENCE_TARGET_NAME = EARTH VECTOR_COMPONENT_UNIT = "UNK" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " The X component of the ESL coordinate system is taken to be positive in the direction away from the Sun measured along the Earth- Sun line." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = ESL_Y REFERENCE_OBJECT_NAME = SUN REFERENCE_TARGET_NAME = EARTH VECTOR_COMPONENT_UNIT = "UNK" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " The Y component of the ESL coordinate system is taken to be positive away from the Sun in the direction of orbital motion (dawn) and lying in the ecliptic plane. " END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = ESL_Z REFERENCE_OBJECT_NAME = SUN REFERENCE_TARGET_NAME = EARTH VECTOR_COMPONENT_UNIT = "UNK" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " The Z component of the ESL coordinate system is taken to be the Sun-centered pole of the ecliptic plane and positive in the northward direction (upward normal)." END_OBJECT = VECTORD END_OBJECT = VECTOR END_OBJECT = COORDINATE /* /**************************************************************************** /* Inertial Cartesian Coordinate System - Equatorial /**************************************************************************** OBJECT = COORDINATE COORDINATE_SYSTEM_ID = ICC_EQTL OBJECT = COORDINFO COORDINATE_SYSTEM_NAME = "EQUATORIAL INERTIAL CART COORD" COORDINATE_SYSTEM_CENTER_NAME = "UNK" COORDINATE_SYSTEM_REF_EPOCH = "UNK" /* 1950.0 */ COORDINATE_SYSTEM_DESC = " The Equatorial Inertial Cartesian Coordinate System is defined for the reference epoch of 1950.0 The X-direction is positive away from the reference body towards the Vernal Equinox which is determined by the line of intersection between the mean Earth equatorial plane and the ecliptic plane of reference. The Y direction is measured outward from the center of the reference body, perpendicular to and east of the the X-axis, and lying in the equatorial plane of reference. The Z direction is positive toward the north equatorial pole of reference, from the center of the reference body." END_OBJECT = COORDINFO OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = ICC_X REFERENCE_OBJECT_NAME = "N/A" REFERENCE_TARGET_NAME = "N/A" VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = "The X-direction is positive away from the reference body towards the Vernal Equinox which is determined by the line of intersection between the mean Earth equatorial plane and the ecliptic plane of reference." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = ICC_Y REFERENCE_OBJECT_NAME = "N/A" REFERENCE_TARGET_NAME = "N/A" VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = "The Y direction is measured outward from the center of the reference body, perpendicular to and east of the the X-axis, and lying in the equatorial plane of reference." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = ICC_Z REFERENCE_OBJECT_NAME = "N/A" REFERENCE_TARGET_NAME = "N/A" VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = "The Z direction is positive toward the north equatorial pole of reference, from the center of the reference body." END_OBJECT = VECTORD END_OBJECT = VECTOR END_OBJECT = COORDINATE /* /**************************************************************************** /* Inertial Cartesian Coordinate System - Ecliptic /**************************************************************************** OBJECT = COORDINATE COORDINATE_SYSTEM_ID = ICC_ECLP OBJECT = COORDINFO COORDINATE_SYSTEM_NAME = "ECLIPTIC INERTIAL CART COORDS" COORDINATE_SYSTEM_CENTER_NAME = "UNK" COORDINATE_SYSTEM_REF_EPOCH = "UNK" /* 1950.0 */ COORDINATE_SYSTEM_DESC = " The Equatorial Inertial Cartesian Coordinate System is defined for the reference epoch of 1950.0 The X-direction lies in the Ecliptic Plane and is positive away from the reference body towards the Vernal Equinox which is determined by the line of intersection between the mean Earth equatorial plane and the ecliptic plane of reference. The Y direction is measured outward from the center of the reference body, perpendicular to and east of the the X-axis, and lying in the ecliptic plane of reference. The Z direction is positive toward the north ecliptic pole of reference, from the center of the reference body." END_OBJECT = COORDINFO OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = ICC_X REFERENCE_OBJECT_NAME = "N/A" REFERENCE_TARGET_NAME = "N/A" VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = "The X-direction lies in the Ecliptic Plane and is positive away from the reference body towards the Vernal Equinox which is determined by the line of intersection between the mean Earth equatorial plane and the ecliptic plane of reference." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = ICC_Y REFERENCE_OBJECT_NAME = "N/A" REFERENCE_TARGET_NAME = "N/A" VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = "The Y direction is measured outward from the center of the reference body, perpendicular to and east of the the X-axis, and lying in the ecliptic plane of reference." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = ICC_Z REFERENCE_OBJECT_NAME = "N/A" REFERENCE_TARGET_NAME = "N/A" VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = "The Z direction is positive toward the north ecliptic pole of reference, from the center of the reference body." END_OBJECT = VECTORD END_OBJECT = VECTOR END_OBJECT = COORDINATE /* /**************************************************************************** /* Body-Fixed Spherical Coordinate System /**************************************************************************** /* MODIFICATIONS: /* 930223 -- MKNIFFIN /* created template OBJECT = COORDINATE COORDINATE_SYSTEM_ID = BFS_CRDS OBJECT = COORDINFO COORDINATE_SYSTEM_NAME = "BODY FIXED SPHERICAL COORDS" COORDINATE_SYSTEM_CENTER_NAME = "UNK" COORDINATE_SYSTEM_REF_EPOCH = "UNK" COORDINATE_SYSTEM_DESC = " The body-fixed spherical coordinate system is the familiar Geographic coordinate system at Earth generalized to other planets. The system consists of the components Radius, Latitude, Longitude. The definition of the prime meridian varies for each planet as does the rotation period. It is crucial to know the exact definition of these variables when changing the reference body. Note: This coordinate system rotates with the reference body." END_OBJECT = COORDINFO OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = RADIUS REFERENCE_OBJECT_NAME = "N/A" REFERENCE_TARGET_NAME = "SPACECRAFT" VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " Radius: Distance from the reference body to the spacecraft." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = LATITUDE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = PHI REFERENCE_OBJECT_NAME = "N/A" REFERENCE_TARGET_NAME = "SPACECRAFT" VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " phi = Latitude: The body-centered latitude of the spacecraft measured positive north of the reference body's equatorial plane." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = LONGITUDE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = THETA REFERENCE_OBJECT_NAME = "N/A" REFERENCE_TARGET_NAME = "SPACECRAFT" VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = " theta - Longitude: the longitude of the spacecraft measured eastward from the prime meridian of the reference body to the projection of the radius vector on the equatorial plane." END_OBJECT = VECTORD END_OBJECT = VECTOR END_OBJECT = COORDINATE /* /**************************************************************************** /* Spacecraft Centered Ecliptic Coordinates /**************************************************************************** /* MODIFICATIONS: /* 930223 -- MKNIFFIN /* created template OBJECT = COORDINATE COORDINATE_SYSTEM_ID = SCC_ECLP OBJECT = COORDINFO COORDINATE_SYSTEM_NAME = "SC CENTERED ECLIPTIC COORDS" COORDINATE_SYSTEM_CENTER_NAME = "SPACECRAFT" COORDINATE_SYSTEM_REF_EPOCH = "UNK" /* 1950.0 */ COORDINATE_SYSTEM_DESC = " The Spacecraft Centered Ecliptic coordinates system (Xe, Ye, Ze) is used to describe the locations of the roll reference celestial objects (Sun or star) and the planet Venus. The coordinate system is centered at the spacecraft center of mass. The Xe-Ye plane is parallel to the Ecliptic Plane and the Ze axis points to the North Ecliptic Pole. The Xe axis points towards the Vernal Equinox. Directions in this coordinate system are described by Celestial Longitude and Celestial Latitude." END_OBJECT = COORDINFO OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = Xe REFERENCE_OBJECT_NAME = "SPACECRAFT" REFERENCE_TARGET_NAME = "N/A" VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = "The Xe-direction lies in the plane parallel to the Ecliptic Plane which passes through the spacecraft center of mass. It is positive away from the spacecraft towards the Vernal Equinox which is determined by the line of intersection between the mean Earth equatorial plane and the ecliptic plane of reference." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = Ye REFERENCE_OBJECT_NAME = "SPACECRAFT" REFERENCE_TARGET_NAME = "N/A" VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = "The Ye-direction is measured outward from the center of the spacecraft perpendicular to and east of the the X-axis, and lying in the plane parallel to the Ecliptic Plane which passes through the spacecraft center of mass." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = Ze REFERENCE_OBJECT_NAME = "SPACECRAFT" REFERENCE_TARGET_NAME = "N/A" VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = "The Ze-direction is positive toward the North Equatorial Pole of reference, measured from the center of mass of the spacecraft." END_OBJECT = VECTORD END_OBJECT = VECTOR END_OBJECT = COORDINATE /* /**************************************************************************** /* Non-Rotating Spin Coordinates /**************************************************************************** /* MODIFICATIONS: /* 930223 -- MKNIFFIN /* created template OBJECT = COORDINATE COORDINATE_SYSTEM_ID = NRSC OBJECT = COORDINFO COORDINATE_SYSTEM_NAME = "NON-ROTATING SPIN COORDINATES" COORDINATE_SYSTEM_CENTER_NAME = "SPACECRAFT" COORDINATE_SYSTEM_REF_EPOCH = "UNK" /* 1950.0 */ COORDINATE_SYSTEM_DESC = " The roll angle of the roll reference object will be calculated in this coordinate system as well as the roll angles of the Fs, RIP, RAM, and NADIR signals. The non-rotating coordinate system (Wx, Wy, Wz) is centered at the spacecraft center of mass. The Wz-axis is parallel to the spacecraft spin axis. The Wx-Wy plane is perpendicular to the spacecraft spin axis. The Wx-Wz plane includes the Vernal Equinox of reference. Thus the Wx-axis is at the intersection of the plane perpendicular to the spacecraft spin axis and the plane containing the spin axis and the Vernal Equinox. Roll angles in this coordinate system are measured in the Wx-Wy plane from the roll reference direction." END_OBJECT = COORDINFO OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = Wx REFERENCE_OBJECT_NAME = "SPACECRAFT" REFERENCE_TARGET_NAME = "N/A" VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = "The Wx-direction is positive away from the spacecraft center of mass in the direction defined by the intersection of the plane perpendicular to the spin axis and the plane containing the Vernal Equinox and the spin axis." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = Wy REFERENCE_OBJECT_NAME = "SPACECRAFT" REFERENCE_TARGET_NAME = "N/A" VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = "The Wy-direction is measured outward from the center of mass of the spacecraft, perpendicular to and east of the the X-axis, and lying in the plane perpendicular to the spacecraft spin axis." END_OBJECT = VECTORD END_OBJECT = VECTOR OBJECT = VECTOR VECTOR_COMPONENT_TYPE = RANGE OBJECT = VECTORCOMP VECTOR_COMPONENT_ID = Wz REFERENCE_OBJECT_NAME = "SPACECRAFT" REFERENCE_TARGET_NAME = "N/A" VECTOR_COMPONENT_UNIT = "N/A" END_OBJECT = VECTORCOMP OBJECT = VECTORD VECTOR_COMPONENT_TYPE_DESC = "The Wz-direction is parallel to the spacecraft spin axis, measured from the spacecraft center of mass, positive in the direction of the spacecraft angular momentum." END_OBJECT = VECTORD END_OBJECT = VECTOR END_OBJECT = COORDINATE /* /****************** DATA SET PROCESSING TEMPLATE ******************************/ /* MODIFICATIONS */ /* 930224 -- MKNIFFIN */ /* Last changes made */ /* */ /* Template: Data Set Processing Template Rev: 19890121 */ /* */ /* Note: This template shall be repeated for each */ /* source dataset id used in production of the */ /* dataset id in the dataset template. */ /* */ /* Hierarchy: DSPROCESSING */ OBJECT = DSPROCESSING SOURCE_DATA_SET_ID = "N/A" SOFTWARE_NAME = "PVONMS" PRODUCT_DATA_SET_ID = "PVO-V-ONMS-5-SUPERTHERMALIONLOC-V1.0" END_OBJECT = DSPROCESSING /****************** DATA SET PROCESSING TEMPLATE ******************************/ /* MODIFICATIONS */ /* 930224 -- MKNIFFIN */ /* Last changes made */ /* */ /* Template: Data Set Processing Template Rev: 19890121 */ /* */ /* Note: This template shall be repeated for each */ /* source dataset id used in production of the */ /* dataset id in the dataset template. */ /* */ /* Hierarchy: DSPROCESSING */ OBJECT = DSPROCESSING SOURCE_DATA_SET_ID = "N/A" SOFTWARE_NAME = "PVONMS" PRODUCT_DATA_SET_ID = "PVO-V-ONMS-4-NEUTRALDENSITY-12SEC-V1.0" END_OBJECT = DSPROCESSING /****************** DATA SET PROCESSING TEMPLATE ******************************/ /* MODIFICATIONS */ /* 930224 -- MKNIFFIN */ /* Last changes made */ /* */ /* Template: Data Set Processing Template Rev: 19890121 */ /* */ /* Note: This template shall be repeated for each */ /* source dataset id used in production of the */ /* dataset id in the dataset template. */ /* */ OBJECT = DSPROCESSING SOURCE_DATA_SET_ID = "N/A" SOFTWARE_NAME = "PVONMS" PRODUCT_DATA_SET_ID = "PVO-V-ONMS-3-NEUTRALDENSITY-HIRES-V1.0" END_OBJECT = DSPROCESSING /****************** DATA SET PROCESSING TEMPLATE ******************************/ /* MODIFICATIONS */ /* 930224 -- MKNIFFIN */ /* Last changes made */ /* */ /* Template: Data Set Processing Template Rev: 19890121 */ /* */ /* Note: This template shall be repeated for each */ /* source dataset id used in production of the */ /* dataset id in the dataset template. */ /* */ OBJECT = DSPROCESSING SOURCE_DATA_SET_ID = "N/A" SOFTWARE_NAME = "PVONMS" PRODUCT_DATA_SET_ID = "PVO-V-ONMS-4-SUPERTHRMLOXYGN-12SEC-V1.0" END_OBJECT = DSPROCESSING /******************** DATA SET PROCESSING TEMPLATE ****************************/ /* MODIFICATIONS */ /* 930224 -- MKNIFFIN */ /* Last changes made */ /* */ /* Template: Data Set Processing Template Rev: 19890121 */ /* */ /* Note: This template shall be repeated for each */ /* source dataset id used in production of the */ /* dataset id in the dataset template. */ /* */ OBJECT = DSPROCESSING SOURCE_DATA_SET_ID = "N/A" SOFTWARE_NAME = "PVONMS" PRODUCT_DATA_SET_ID = "PVO-V-ONMS-3-SUPERTHRMLOXYGN-HIRES-V1.0" END_OBJECT = DSPROCESSING /****************** DATA SET PROCESSING TEMPLATE ******************************/ /* MODIFICATIONS */ /* 930224 -- MKNIFFIN */ /* Last changes made */ /* */ /* Template: Data Set Processing Template Rev: 19890121 */ /* */ /* Note: This template shall be repeated for each */ /* source dataset id used in production of the */ /* dataset id in the dataset template. */ /* */ OBJECT = DSPROCESSING SOURCE_DATA_SET_ID = "N/A" SOFTWARE_NAME = "PVONMS" PRODUCT_DATA_SET_ID = "PVO-V-ONMS-4-IONMAXCOUNTRATE-12SEC-V1.0" END_OBJECT = DSPROCESSING /*********************** ONMS Parameter Template ******************************/ /* MODIFICATIONS: */ /* */ /* Template: Parameter Template Rev: 19890121 */ /* */ /* Note: This template shall be completed for each combination */ /* of data set parameter name, instrument parameter */ /* name and instrument host id associated with a dataset. */ /* */ /* Hierarchy: PARAMETER */ OBJECT = PARAMETER INSTRUMENT_HOST_ID = "PVO" DATA_SET_PARAMETER_NAME = "NEUTRAL COMPOSITION" INSTRUMENT_PARAMETER_NAME = "NEUTRAL DENSITY" IMPORTANT_INSTRUMENT_PARMS = 1 END_OBJECT = PARAMETER /*********************** ONMS Parameter Template ******************************/ /* MODIFICATIONS: */ /* */ /* Template: Parameter Template Rev: 19890121 */ /* */ /* Note: This template shall be completed for each combination */ /* of data set parameter name, instrument parameter */ /* name and instrument host id associated with a dataset. */ /* */ /* Hierarchy: PARAMETER */ OBJECT = PARAMETER INSTRUMENT_HOST_ID = "PVO" DATA_SET_PARAMETER_NAME = "APPARENT FLOW ANGLE" INSTRUMENT_PARAMETER_NAME = "SUPERTHERMAL ION FLUX" IMPORTANT_INSTRUMENT_PARMS = 1 END_OBJECT = PARAMETER /*********************** ONMS Parameter Template ******************************/ /* MODIFICATIONS: */ /* */ /* Template: Parameter Template Rev: 19890121 */ /* */ /* Note: This template shall be completed for each combination */ /* of data set parameter name, instrument parameter */ /* name and instrument host id associated with a dataset. */ /* */ /* Hierarchy: PARAMETER */ OBJECT = PARAMETER INSTRUMENT_HOST_ID = "PVO" DATA_SET_PARAMETER_NAME = "SUPERTHERMAL ION DENSITY" INSTRUMENT_PARAMETER_NAME = "SUPERTHERMAL ION FLUX" IMPORTANT_INSTRUMENT_PARMS = 1 END_OBJECT = PARAMETER /*********************** ONMS Parameter Template ******************************/ /* MODIFICATIONS: */ /* */ /* Template: Parameter Template Rev: 19890121 */ /* */ /* Note: This template shall be completed for each combination */ /* of data set parameter name, instrument parameter */ /* name and instrument host id associated with a dataset. */ /* */ /* Hierarchy: PARAMETER */ OBJECT = PARAMETER INSTRUMENT_HOST_ID = "PVO" DATA_SET_PARAMETER_NAME = "LOCATION" INSTRUMENT_PARAMETER_NAME = "" IMPORTANT_INSTRUMENT_PARMS = 1 END_OBJECT = PARAMETER /********************* ONMS Parameter Desc. Template **************************/ /* MODIFICATIONS: */ /* */ /* Template: Data Set Instrument Parameter Description Template Rev: 19890121 */ /* */ /* Note: This template shall be completed for any */ /* data set or instrument parameter description. */ /* */ /* Hierarchy: DSINSTPARMD */ OBJECT = DSINSTPARMD DATA_SET_OR_INSTRUMENT_PARM_NM = "NEUTRAL DENSITY" DATA_SET_OR_INST_PARM_DESC = " Neutral (particle) density is a parameter derived from the rate at which particles are detected scaled by the probability of detecting individual particles. Neutral particle detectors commonly exclude ionized particles from entering the counting region of the instrument using a charged repeller grid. Density values are commonly reported in cgs units. " END_OBJECT = DSINSTPARMD /********************* ONMS Parameter Desc. Template **************************/ /* MODIFICATIONS: */ /* */ /* Template: Data Set Instrument Parameter Description Template Rev: 19890121 */ /* */ /* Note: This template shall be completed for any */ /* data set or instrument parameter description. */ /* */ /* Hierarchy: DSINSTPARMD */ OBJECT = DSINSTPARMD DATA_SET_OR_INSTRUMENT_PARM_NM = "NEUTRAL COMPOSITION" DATA_SET_OR_INST_PARM_DESC = " Neutral (particle) composition is a parameter which describes the total density of neutral particles in terms of constituent particle densities." END_OBJECT = DSINSTPARMD /********************* ONMS Parameter Desc. Template **************************/ /* MODIFICATIONS: */ /* */ /* Template: Data Set Instrument Parameter Description Template Rev: 19890121 */ /* */ /* Note: This template shall be completed for any */ /* data set or instrument parameter description. */ /* */ /* Hierarchy: DSINSTPARMD */ OBJECT = DSINSTPARMD DATA_SET_OR_INSTRUMENT_PARM_NM = "SUPERTHERMAL ION FLUX" DATA_SET_OR_INST_PARM_DESC = " Superthermal ion flux is a measure of the rate at which ions (whose energies are high with respect to the characteristic temperature of the bulk distribution - 'superthermal') pass through a unit volume." END_OBJECT = DSINSTPARMD /********************* ONMS Parameter Desc. Template **************************/ /* MODIFICATIONS: */ /* */ /* Template: Data Set Instrument Parameter Description Template Rev: 19890121 */ /* */ /* Note: This template shall be completed for any */ /* data set or instrument parameter description. */ /* */ /* Hierarchy: DSINSTPARMD */ OBJECT = DSINSTPARMD DATA_SET_OR_INSTRUMENT_PARM_NM = "APPARENT FLOW ANGLE" DATA_SET_OR_INST_PARM_DESC = " An apparent flow angle is the projection of a true flow angle into some reference plane." END_OBJECT = DSINSTPARMD /********************* ONMS Parameter Desc. Template **************************/ /* MODIFICATIONS: */ /* */ /* Template: Data Set Instrument Parameter Description Template Rev: 19890121 */ /* */ /* Note: This template shall be completed for any */ /* data set or instrument parameter description. */ /* */ /* Hierarchy: DSINSTPARMD */ OBJECT = DSINSTPARMD DATA_SET_OR_INSTRUMENT_PARM_NM = "LOCATION" DATA_SET_OR_INST_PARM_DESC = " " END_OBJECT = DSINSTPARMD /******************************* Software Information *************************/ /* Template: Software Information Template Rev: 19890121 */ /* */ /* Note: This template is completed for each node */ /* software application referenced in the PDS. */ /* */ /* Hierarchy: SOFTWARE */ OBJECT = SOFTWARE SOFTWARE_NAME = "PVONMS" NODE_ID = "N/A" SOFTWARE_RELEASE_DATE = 1993-03-23 SOFTWARE_TYPE = "N/A" COGNIZANT_FULL_NAME = "DR. WAYNE T. KASPRZAK" SOFTWARE_ACCESSIBILITY_DESC = " The software is available at the NASA/Goddard Space Flight Center. If interested contact PPI node or Dr. Kasprzak." SOFTWARE_DESC = " All data were processed at NASA/Goddard Space Flight Center using custom programmed software. The data represent a reduction to physical units (density, flux) and were processed from an intermediate engineering unit file (current, count/sec etc.). Unit and 1/8 unit amu sweeps are not contained in the processed data sets but are available from the engineering unit data set. The engineering unit data is converted to ambient values using spacecraft velocity and attitude, the theoretical expected system response, and the corresponding calibration factors. Superthermal ion data for species other than O{+} is available in engineering unit form. NOTE: Software is available by contacting the PPI Node." END_OBJECT = SOFTWARE