Data Set Information
DATA_SET_NAME STARDUST CIDA DATA
DATA_SET_ID SDU-C/D-CIDA-1-EDF/HK-V1.0
NSSDC_DATA_SET_ID
DATA_SET_TERSE_DESCRIPTION
DATA_SET_DESCRIPTION This description was written by J. Kissel, J. Silen, B. Semenov, and C. Acton. Data Set Overview : This data set contains raw time-of-flight spectrum data, which are called ``events'' and are Level 1 data, and associated ancillary data produced by the Stardust Cometary and Interstellar Dust Analyzer Instrument (CIDA), a time-of-flight mass spectrometer. The data were obtained during two mission episodes: flyby of comet Wild-2, and cruise, which includes all other times except the flyby. Each package of ``event'' and ancillary data is telemetered to the ground as an Experiment Data Frame (EDF). The term ``event'' is used to refer to any type of non-ancillary data returned from the CIDA instrument. Some of these events are test frames, generated by telecommands to ensure continued correct operation of the instrument. Some events are the result of a CIDA re-boot, which may have been commanded or may have been a result of some other spacecraft condition. Some events are known to have been generated by noise within the CIDA electronics. All of these are considered non-scientific data and are distinguished from scientific data by TARGET_NAME set to ``NON SCIENCE'' in the data labels and the data set index file. 459 of 535 (86%) EDFs in this data set contain non-scientific data. The remainder are events that may or may not contain spectra resulting from actual particle hits; it is only through detailed analysis that the user may make a determination of the cause of the event and the resulting spectra may be interpreted. These EDFs are distinguished by TARGET_NAME in the labels and index file set to either ``81P/WILD 2 (1978 A2)'' (31 of 535 EDFs) or ``INTERSTELLAR PARTICLES'' (45 of 535 EDFs). While included for completeness, the CIDA housekeeping and other ancillary data are NOT needed for generation or interpretation of CIDA spectra. The CIDA event files include selected observation geometry parameters, derived from the then-current SPICE kernels and allied SPICE Toolkit software. These SPICE kernels are available in a separate PDS Stardust data set, SDU-C-SPICE-6-V1.0. The CIDA event data are supplemented with a PDS index file providing a set of parameters computed for every CIDA event; this information may be easily loaded into a database or spreadsheet to facilitate searches for CIDA data meeting certain user-specified observing conditions. Data Collection Periods : Cruise Collection Period ------------------------ During the cruise from earth to Wild-2 and after the Wild 2 encounter the CIDA instrument was operating during the following times: Start Stop ------------------- ------------------- 1999-02-22 1999-07-30 1999-09-13 2000-08-30 2000-10-10 2001-08-16 2002-11-02 2002-11-02 2003-02-04 2003-06-17 2003-07-16 2004-01-02T14:08:24 2004-01-03T01:23:08 2004-03-08 There were a number of short OFF times during these periods as a result of the spacecraft going into safe-mode, spacecraft maneuvers, and other reasons. The one day window on November 02, 2002 was during the Annefrank asteroid flyby, during which no particle hits were detected. Wild 2 Encounter Collection Period ---------------------------------- During the Wild-2 encounter the CIDA instrument was operating during the following time: Start Stop ------------------- ------------------- 2004-01-02T14:27:06 2004-01-03T01:10:20 Data Calibration : The ``calibration'' of time-of-flight mass spectrometer data is in fact the essence of the data analysis process. ``Calibration'' of the data numbers contained in each event, resulting in a determination of if a particulate impact actually occurred, and if so, of the composition of the particle, may be straightforward, but may instead be complex and subjective. This data set includes a document, CALEXAMPL.PDF, providing a complete description of the ``calibration'' of a laboratory test event where the composition of the particle is well known. The document also includes a similar ``calibration'' example for an in-flight event obtained during the Wild 2 flyby. Data Product Type and Format Overview : CIDA data files provided in this archive are divided into two main categories: -- Spectrum Experiment Data Files (Spectrum EDFs), and -- Housekeeping Experiment Data files (HK EDFs). Spectrum EDFs contain the raw CIDA time-of-flight spectrum data. Each Spectrum EDF file is sufficient for analysis in itself. HK EDFs contain temperature, voltage and other engineering data that might prove useful in reviewing the operating characteristics of the instrument, but are NOT needed to interpret the spectrum data. There is only one type of Spectrum EDF, but there are five different types of HK EDFs: -- housekeeping parameters -- configuration parameters -- calibration parameters -- global variable values -- interrupt variable values All CIDA data files are plain ASCII text files containing an attached PDS label. The data are in the form of one (for HK EDFs) or a few (for Spectrum EDFs) PDS-style, fixed-width column, comma-delimited tables, the format and contents of which are defined in the CIDASIS.TXT document included in the archive. Each table contained in the file is identified in the attached label by a separate TABLE object pointing to an external table format file specifying individual table columns. The label format and contents are described in detail in the ONLABELS.TXT file included in the archive. Data Processing : The Stardust CIDA instrument output consisted of a variety of binary data blocks called binary Experiment Data Files (EDFs), each of which contained a set of spectrum or housekeeping data. On board the spacecraft EDFs were packetized by the spacecraft's flight software and downlinked within packets in the spacecraft telemetry stream. For small housekeeping EDFs, multiple EDFs were contained in one spacecraft telemetry packet while for large spectrum EDFs the EDF was split between a few spacecraft packets. A suite of software -- developed and run by the Stardust Data Management and Archive Team (DMA) and collectively referred to as CIDA Telemetry Processing Software (CTPS) -- retrieved packets with CIDA data from the Telemetry Data Server(s)(TDS) used by the Stardust Project, striped off ground system and spacecraft packet headers, and placed the EDF data in a binary EDF collection file for delivery to the CIDA science team. That binary file essentially contained a ``chunk'' of a single stream of concatenated EDFs. The binary EDF collection files were then delivered to the CIDA science Team, which used a set of software -- developed and run by Finnish Meteorological Institute (FMI) and called EDFPARSER/EDF2ASCII -- to combine ``chunks'' into a single telemetry stream, extract individual binary EDFs from it, convert binary data from individual EDFs into ASCII and save the ASCII Spectrum EDF and ASCII HK EDF files in the format in which the data are provided in this data set. For Spectrum EDF data the conversion constituted simply printing byte values as ASCII integers and did not involve any scaling and/or calibration of the values. For the generic EDF header data and HK EDFs it in some cases involved de-multiplexing fields and converting ancillary fields containing count values into physical units -- temperatures, voltages, etc. Ancillary Data : Each Spectrum EDF file includes a table containing a number of derived geometry parameters. These parameters were computed using the following SPICE kernels archived in the Stardust SPICE data set, SDU-C-SPICE-6-V1.0: Kernel Type File Name ------------ ------------------------ LSK naif0007.tls PCK pck00007.tpc SCLK sdu_sclkscet_00080.tsc sdu_sclkscet_00105.tsc FK sdu_v17.tf SPKs sdu_l_1999.bsp sdu_l_2000.bsp sdu_l_2001.bsp sdu_l_2002.bsp sdu_l_2003_w2.bsp' sdu_w2_opnav.bsp CKs sdu_sc_rec_1999_v2.bc sdu_sc_rec_2000_v2.bc sdu_sc_rec_2001_v2.bc sdu_sc_rec_2002_v2.bc sdu_sc_rec_2003_w2_v2.bc sdu_sc_rec_w2_opnav.bc ------------ ------------------------ Coordinate System : The geometry items provided in the geometry table of the Spectrum EDF files are relative to either the ecliptic reference frame of J2000 or the Stardust spacecraft reference frame. Refer to the specification of the geometry table columns to see which parameters are defined in which frame.) The ecliptic reference frame of J2000 is defined as follows: - +Z axis is along Ecliptic North at J2000 epoch (2000 JAN 01 12:00 ET); - +X axis is along vernal Equinox at J2000 epoch; - +Y completes the right hand frame; The Stardust reference frame is defined as follows: - +X axis is along the longer side of the spacecraft bus and points from the aerogel capsule side towards the dust shield side; - +Z is perpendicular to the deployed solar arrays surface and points along the HGA pointing direction; - +Y completes the right hand frame; - the origin of this frame is at the center of the launch vehicle interface ring attached to the shield side of the spacecraft bus. This diagram illustrates the spacecraft reference frame and CIDA mounting with respect to it: || Dust Collector || Array Solar Array Main || Shield +Z .-. Shield || .-. ^| | o | |:|:o:o: `-' || |-------------------. . Solar || | |/| Array || | .-----. CIDA | | <-------o| | | ' | | Return +X +Y . __/ | | Capsule | | `. `. |\| | |--- `. `.---- -----' o--------- | | `. `. \_______/ `-' `.'`. Target ------> ------> ------> .' -------- Nominal . ' Incoming Particle `. ' 40 deg direction during `. Encounter `. Normal to CIDA Target Plane As seen on on the diagram CIDA is mounted on the +Y side of the spacecraft bus. The CIDA target plane is parallel to the spacecraft Y axis. The normal to the target plane is in the XZ plane and 40 degrees from +X towards +Z. The back of the opening between the target and the entrance to the drift tube is shielded, not permitting particles coming from the back (-X side) or top (+Z side) to hit the target. The un-shielded part of the opening and non-planar geometry of the target surface allow impacts by the particles coming from within the angular range of a few degrees towards +Z and about 30 degrees toward -Z, measured from the +X axis. Software : The data in this data set are in standard PDS format -- ASCII text files with comma-delimited, fixed-width columns -- and, therefore, can be viewed by PDS-provided programs or loaded into commercial programs that support comma-delimited formats. For this reason no special processing software is included in this data set. Unresolved Liens on the Data : A request was made by the external peer reviewers to split the data files into separate subdirectories for science and non-science data. Resources were not available to make this change and propagate it through the data set documentation. Users should note that science and non-science data files are mixed in a single directory, and can use the TARGET_NAME field to discriminate among them as needed. The TARGET_NAME field is included in the index provided with this data set. Contact Information : For any questions regarding the data in this archive, contact: Dr. Jochen Kissel, Stardust CIDA Science Lead Dr. Johan Silen, Stardust CIDA Science Team Member Dr. Jouni Ryno, Stardust CIDA S/W Technical Lead
DATA_SET_RELEASE_DATE 2004-07-02T00:00:00.000Z
START_TIME 1999-02-07T12:00:00.000Z
STOP_TIME 2004-03-08T12:00:00.000Z
MISSION_NAME STARDUST
MISSION_START_DATE 1999-02-07T12:00:00.000Z
MISSION_STOP_DATE 2006-01-16T12:00:00.000Z
TARGET_NAME 81P/WILD 2 (1978 A2)
UNKNOWN
TARGET_TYPE COMET
UNKNOWN
INSTRUMENT_HOST_ID SDU
INSTRUMENT_NAME COMETARY AND INTERSTELLAR DUST ANALYZER
INSTRUMENT_ID CIDA
INSTRUMENT_TYPE COSMIC DUST ANALYZER
NODE_NAME Small Bodies
ARCHIVE_STATUS ARCHIVED
CONFIDENCE_LEVEL_NOTE All Experiment Data Frames produced by the CIDA instrument contain a checksum that is validated upon ground receipt. During the processing of the CIDA event EDFs in preparation for delivery with this data set the fundamental validity of each event EDF has been inferred by the CIDA Science Lead and CIDA Science team members by plotting and subsequent visual review of the data structure. As noted earlier, many CIDA events are the result of turn on sequences, test pulses, reboots or noise. These ``non-science'' events are nevertheless included in this data set. Of those events that remain, many appear to contain significant (``real'') spectral data while others appear to contain no data of interest. But it is left to the individual user to ultimately determine which events are meaningful.
CITATION_DESCRIPTION Ryno, J., B.V. Semenov, J. Kissel, J. Silen, and C.H. Acton, STARDUST CIDA DATA, SDU-C/D-CIDA-1-EDF/HK-V1.0, NASA Planetary Data System, 2004.
ABSTRACT_TEXT This data set contains raw time-of-flight spectrum data and associated ancillary data produced by the Stardust Cometary and Interstellar Dust Analyzer Instrument (CIDA), a time-of-flight mass spectrometer. The data were obtained during two mission episodes: flyby of comet Wild-2, and cruise, which includes all other times except the flyby.
PRODUCER_FULL_NAME STARDUST DATA MANAGEMENT AND ARCHIVE TEAM
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