Data Set Information
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MARS GLOBAL SURVEYOR RAW DATA SET - MOI V1.0
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MGS-M-RSS-1-MOI-V1.0
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| NSSDC_DATA_SET_ID |
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| DATA_SET_TERSE_DESCRIPTION |
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| DATA_SET_DESCRIPTION |
Data Set Overview : The Mars Global Surveyor (MGS) Radio Science (RS) Raw Data Archive (RDA) is a time-ordered collection of raw and partially processed data collected during the MGS Mission to Mars. For more information on the investigations see [TYLERETAL1992] and [TYLERETAL2001]. This data set was collected during the Mars Orbit Insertion (MOI) Phase -- while the spacecraft was on final approach to Mars, entering Mars orbit, and adjusting the orbit in preparation for the Mapping Phase. Most of the radio data supported MGS Navigation activities. Occultations captured during January-April 1998, November-December 1998, and February-March 1999 and low periapsis passes over the poles have intrinsic science value of their own. Two types of measurements were conducted during MOI; these are known as closed-loop and open-loop recordings. The closed- loop system used a phase-lock loop in the receiver to track the downlink signal, reporting both amplitude and frequency at rates typically of 1-10 times per second. In the open-loop system, the signal was simply converted to a baseband frequency range; the entire passband was sampled and recorded for later processing. Typical open-loop sampling rates for MGS were 5000 samples per second. Closed-loop data are efficient for characterizing slowly changing signals; open-loop data (because of their much higher volume) are collected only when the signal is very dynamic -- such as during an occultation. The data set includes three primary data types. Archival Tracking Data Files (ATDFs or TDFs) are the most primitive (and most voluminous) product of the closed-loop system. Orbit Data Files (ODFs) are edited versions of ATDFs, specifically targeted to spacecraft navigators and scientists interested in gravity fields. Original Data Records (ODRs) are the primary data type from the open-loop system. Typical users of these data might analyze range and Doppler measurements in ATDFs or ODFs to derive the spacecraft trajectory during MOI. Relevant questions would include the measurement uncertainties in range and Doppler at different DSN antennas; these could set constraints on any model of Mars' gravity field developed later, for example. During MOI the spacecraft orbit was lower than at any other time during the mission; gravity investigators interested in detecting and measuring concentrations of mass at or near the surface could find the ODF's in this data set to be particularly interesting. Users of ODRs could identify and characterize anomalous signals within the recorded passband, derive the drift of the UltraStable Oscillator (USO), and calculate Allan Deviation for various radio science configurations. Data collected during aerobraking could be used to infer the structure of the upper Mars atmosphere. Parameters : The ATDF is the primary output from the MGS closed-loop system. ATDFs have 150 fields, though not all had been assigned during the MGS era. Each ATDF in the data set is accompanied by a full PDS label which defines both the content and the format (at the bit level) of the file. ATDF data fields include: Range High- or low-rate Doppler High or low-rate downlink phase Differential Range vs Integrated Doppler (DRVID) Allan deviation Smoothed noise Uplink phase Other information included in ATDF data records is date and time; spacecraft ID; ground station and its configuration; status flags and values reported by various ground systems; calibration values, noise estimates, and tolerances (station delay, transmitter power, etc.); and signal strength. The ODF is an edited version of the ATDF; it is a smaller file, issued more frequently than the ATDF. It contains the most important information (range and Doppler) needed by spacecraft navigators and investigators interested in determining gravitational fields of bodies such as Mars. Each ODF is accompanied by a full PDS label which describes both the content and format of the associated file. ODF data fields include: Narrowband spacecraft VLBI, Doppler mode (cycles) Narrowband spacecraft VLBI, phase mode (cycles) Narrowband quasar VLBI, Doppler mode (cycles) Narrowband quasar VLBI, phase mode (cycles) Wideband spacecraft VLBI (nanoseconds) Wideband quasar VLBI (nanoseconds) One-way Doppler (Hertz) Two-way Doppler (Hertz) Three-way Doppler (Hertz) One-way total count phase (cycles) Two-way total count phase (cycles) Three-way total count phase (cycles) PRA planetary operational discrete spectrum range (range units) SRA planetary operational discrete spectrum range (range units) RE[GSTDN] range (nanoseconds) Azimuth angle (degrees) Elevation angle (degrees) Hour angle (degrees) Declination angle (degrees) Open loop data records (ODRs) contain 8- or 12-bit samples of receiver output. Each block of (typically) 1000 data samples is accompanied by a 166 byte header. Each ODR is accompanied by a full PDS label which describes both the content and format of the file at the bit level. Header information includes: Date and time of the first data sample Sample rate and channel assignments Receiver local oscillator (POCA) frequency Attenuator settings RMS voltages at several stages in the receiving chain Processing : ATDFs are screened for 'bad' data points, which are removed before the file is released by the Jet Propulsion Laboratory (JPL) Radio Metric Data Conditioning Team (RMDCT). ODFs are abstracted from subsets of ATDF data. The open-loop data delivered to Stanford were usually in the ODS (Original Data Stream) format. ODS packets were converted to the older ODR (Original Data Record) format for consistency in subsequent processing and archive. Headers applied by the Ground Data System (GDS) during packet handling have not been retained; they contained no additional information about the data acquisition. In some cases, where the GDS corrupted the ODS during delivery (or lost it entirely), data have been recovered from tape in ODR format. The resultant data (whether from ODS conversion or tape) accurately represent the output of the DSCC Spectrum Processing (DSP) Subsystem at the DSN station. A full PDS label accompanies each ODR file and gives a bit level description of the content and format. A 32-byte label at the beginning of each ODR tape is not included in the data file. The 32-byte label gives the version of the data taking software; this information has been copied to the PDS label that accompanies the data file. The software version recorded in the 'NOTE' keyword is more likely to be accurate than the version recorded with the 'SOFTWARE_VERSION' keyword. Because the 32-byte label is no longer part of the data stream, users can treat the remaining file as an integral number of fixed-length records. The 32-byte label was never defined in the ODS. Data : Data are stored on CD-WO volumes approximately chronologically. CD volumes were usually defined by the dates of included spacecraft engineering and DSN monitor data (data types ECH and MCH, respectively). ECH and MCH files were the most regular, and often the largest, collected on a daily basis. Files of other types were sometimes delayed in delivery to Stanford and may be out of strict chronological order on the CDs. Users should consult listings in the INDEX/CUMINDEX.TAB file to ascertain full coverage of each data type. ATDFs were delivered approximately weekly during MGS MOI. ATDFs are stored in the TDF directory on archival volumes. File names are of the form ydddeeeC.TDF where y is the one-digit year of the first data, ddd is the three-digit day-of-year of the first data, eee is the three-digit day- of-year of the last data, and C is a single letter (beginning with 'A') denoting the sequence in which files with the same ydddeee were handled. Generally ydddeeeB.TDF is a revised version of ydddeeeA.TDF. The PDS label has file name ydddeeeC.LBL. The typical ATDF contains about 39 Mbytes. ODFs were issued at least daily throughout MGS MOI; during periods of high spacecraft activity (such as around maneuvers) ODFs were released as often as hourly. Most ODFs released during MOI are included in the archival data set. Of those that were missed, most were generated by special request, and Stanford did not receive a release notice. ODFs are stored in the ODF directory. File names are of the form ydddeeeC.ODF where the file name components are the same as for the ATDF (previous paragraph). In most cases ydddeeeB.ODF was NOT simply a revised version of ydddeeeA.ODF; there were many requests for special ODF processing -- to obtain higher time resolution over short intervals, for example. The PDS label has file name ydddeeeC.LBL. Typical ODF file sizes are small multiples of 8064 bytes (e.g., less than 100 kB). Original Data Records (ODRs) were produced whenever the DSP was set to 'run' mode. These files are stored in the ODR directory. In most cases, the entire DSP run was collected into a single ODR file. But in other cases, it was more convenient to subdivide the DSP data; queries were issued for shorter time spans, and separate files were produced. File names are of the form ydddhhmm.ODR where y is the one-digit year of the first data, ddd is the day-of-year of the first data, hh is the hour on which the first sample was taken, and mm was the minute on which the first sample was taken. In cases where two files had the same ydddhhmm (for example, two DSN stations began recording at the same time, or a second query was submitted for data which appeared suspicious after the first query was processed), the less significant digit in mm of the second file was converted to a letter ('0' became 'A', '1' became 'B', ..., '9' became 'J'). In cases were three files had the same ydddhhmm, the less significant mm digit was converted to 'K', 'M', etc. The PDS label has file name ydddhhmm.LBL. At 5000 samples per second, a two-hour 12-bit test would yield a 60 MB ODR -- one X-band (RCP) channel; 5 records per second, each with 1000 12-bit samples and a 166-byte header. At 200 samples per second, an eight-hour 8-bit run would yield a 33 MB ODR -- four channels (one X-RCP, the others null); 2 records per second with 100 8-bit samples per channel and a 166-byte header. Ancillary Data : An extensive set of ancillary files is needed for proper analysis and interpretation of the radio data (file types TDF, ODF, and ODR). These are organized in parallel directories and stored approximately chronologically. When a file type is not represented on a CD-WO volume, the corresponding directory has been omitted. With the exception of files stored in the CALIB directory, ancillary files appear on only one CD-WO volume. Users should refer to the INDEX/CUMINDEX.TAB listing to locate ancillary files. Files in the CALIB Directory ---------------------------- Files in the CALIB directory are those likely to have wide applicability in working with the raw data. They help unpack and allow use of the raw data, rather than being 'instrument' calibration data per se. They include decommutation maps, clock conversion files, files of planetary constants, leapsecond files, and files needed for display of data on the MGS Science Operations Planning Computer (SOPC). Each file is accompanied by a PDS minimal label. Clock Conversion files were produced by the JPL/PDS Navigation Ancillary Information Facility (NAIF) for use with NAIF-developed and MGS-provided software. These are ASCII files of variable length records. Each record is delimited by an ASCII carriage-return (ASCII 13) line-feed pair (ASCII 10), which may need to be converted to either or before the file is used on the local machine. File names have the form ydddeeeC.SCK where y is the one-digit year of the first date covered, ddd is the day-of-year of the first date covered, eee is the day-of-year of the last date covered, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. An alternate naming scheme was adopted part way through MOI; those files have names of the form TSCnnnnn.SCK, where nnnnn is a sequence number beginning with 00001 and the file with the highest number is the most recent. The value of nnnnn is set by NAIF. Planetary Constants files were produced by the JPL/PDS Navigation Ancillary Information Facility (NAIF) for use with NAIF-developed and MGS-provided software. These are ASCII files of variable length records. Each record is delimited by an ASCII carriage-return (ASCII 13) line-feed pair (ASCII 10), which may need to be converted to either or before the file is used on the local machine. File names have the form PCKydddC.TPC where y is the one-digit year of the file creation date, ddd is the day-of-year of the file creation date, and C is a character denoting sequence when more than one file with the same yddd is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. Leapsecond files were produced by the JPL/PDS Navigation Ancillary Information Facility (NAIF) for use with NAIF-developed and MGS-provided software. These are ASCII files of variable length records. Each record is delimited by an ASCII carriage-return (ASCII 13) line-feed pair (ASCII 10), which may need to be converted to either or before the file is used on the local machine. File names have the form LSKydddC.TLS where y is the one-digit year of the file creation date, ddd is the day-of-year of the file creation date, and C is a character denoting sequence when more than one file with the same yddd is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. Channel Conversion Language files come in three types -- source, dependency, and binary. File names are of the forms CCLydddS.SRC, CCLydddD.BIN, and CCLydddB.BIN, respectively, where y is the one-digit year of the file creation date and ddd is the day-of-year of the file creation date. Source files are ASCII files of variable length records. Each record is delimited by an ASCII carriage-return (ASCII 13) line-feed pair (ASCII 10), which may need to be converted to either or before the file is used on the local machine. Dependency and binary files are identical to those used on the SOPC. Source and binary files are typically 500 kB; dependency files are typically 15 kB. Channel Conversion Language files are used in converting raw binary data in telemetry streams to meaningful numbers. Channel Parameter Table files come in two types -- source and binary. File names are of the forms CPTydddS.SRC and CCLydddB.BIN, respectively, where y is the one-digit year of the file creation date and ddd is the day-of-year of the file creation date. Source files are ASCII files of variable length records. Each record is delimited by an ASCII carriage-return (ASCII 13) line-feed pair (ASCII 10), which may need to be converted to either or before the file is used on the local machine. Binary files are identical to those used on the SOPC. Source and binary files are typically less than 1 MB. Channel Parameter Table files are used in converting raw binary data in telemetry streams to meaningful numbers. Template Description Language files come in two types -- source and binary. File names are of the forms TDLydddS.SRC and TDLydddB.BIN, respectively, where y is the one-digit year of the file creation date and ddd is the day-of-year of the file creation date. Source files are ASCII files of variable length records. Each record is delimited by an ASCII carriage-return (ASCII 13) line-feed pair (ASCII 10), which may need to be converted to either or before the file is used on the local machine. Binary files are identical to those used on the SOPC. Source and binary files are typically less than 1 MB. Template Description Language files are used during display of data on the SOPC. Decommutation Map files come in two types -- source and binary. File names are of the forms DCSxxxxx.SRC and DCOxxxxx.BIN, respectively, where xxxxx is a mnemonic for the map. Source files are ASCII files of variable length records. Each record is delimited by an ASCII carriage- return (ASCII 13) line-feed pair (ASCII 10), which may need to be converted to either or before the file is used on the local machine. Binary files are identical to those used on the SOPC. Source and binary files are typically less than 200 kB. Decommutation Map files are used in converting raw binary packet data to channelized formats. On the SOPC, they are used with the MGS-provided program mapx. NB: CCL, CPT, TDL, and decommutation files were used with software provided by the MGS project to extract and scale 'engineering' data from spacecraft and ground DSN systems. In early 2007 a combined software/hardware upgrade mandated by JPL left Stanford unable to process these telemetry streams absent a significant recovery effort. Since the spacecraft had gone silent three months earlier, it was decided not to make the investment. Thus Stanford is no longer able to extract these engineering data from ECH and MCH binary files (see below). It is likely that other users of the data would find this task to be equally challenging. However, the CSV*.ECH, CSV*.MCH, ECS, and ECT files are ASCII and should represent the most likely engineering channels to be of interest to radio science. Angular Momentum Desaturation Files (AMD Directory) --------------------------------------------------- Angular Momentum Desaturation files were produced by the MGS Spacecraft Team (SCT). Each AMD file documents a set of AMD events on the spacecraft. These are ASCII files of variable length records. Each record is delimited by an ASCII carriage-return (ASCII 13) line-feed pair (ASCII 10), which may need to be converted to either or before the file is used on the local machine. File names have the form ydddeeeC.AMD where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. Each AMD file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. Typical file sizes are less than 1500 bytes. Channelized Engineering Data Files (ECH Directory) --------------------------------------------------- Channelized Engineering Data files were produced by the MGS query server, operating on telemetry packets stored in the MGS Central Data Base (CDB). These are binary files, usually representing the collection of raw spacecraft engineering data received from a 24 hour period; they are not readily interpretable by end users. File names have the form ydddeeeC.ECH where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. Each ECH file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. File sizes can be as large as 200 MB. In general, an ECH file can be derived from the corresponding EPK file using MGS-provided software and a decommutation map. Also in some ECH directories are ASCII tables of extracted channel values--channelized state vectors, or CSV files. These are values for a limited number of potentially useful ECH channels that have been saved in tabular form. CSV files in the ECH directory have names of the form CSVydddC.ECH where y, ddd, and C are the same as for the corresponding ECH file. Each CSV file is accompanied by a detached PDS label with name CSVydddC.LBL which completely describes the format and content of the CSV file. NB: Stanford is no longer able to process binary ECH files; see note above at the end of the section 'Files in the CALIB Directory' for details. Engineering Channelized Data Summary Files (ECS Directory) --------------------------------------------------- Engineering Channelized Summary Data Files were created at Stanford during ingestion of spacecraft engineering data. Each file contains a summary line for each channel processed from the previous day's telemetry. The ECS file thus gives a snapshot (mean and standard deviation) of each channel on each day. ECS files are PDS TABLE objects; each is fully described as to format and content by a detached PDS label. File names are of the form ydddeeeC.ECS where y is the one-digit year of the first data, ddd is the three-digit day-of-year of the first data, eee is the three-digit day-of-year of the last data, and C is a character denoting sequence when more than one file with the same ydddeee is handled. File sizes vary depending on the number of channels processed; typical growth is 4000 bytes per day. Engineering Channel Table Files (ECT Directory) --------------------------------------------------- Engineering Channel Table Data Files are created at Stanford during ingestion of spacecraft engineering data. Each ECT file is an ASCII table of time-ordered values from a single spacecraft engineering channel, and each file is fully described by a detached PDS label. File names are of the form XXXydddC.ECT where XXX is a unique identifier for the engineering channel, y is the one-digit year of the first data, ddd is the three-digit day-of-year of the first data, and C is a character denoting sequence when more than one file with the same yddd is handled. File sizes vary depending on the rate at which a channel was sampled; they are typically under 100 kB. The detached label has file name XXXydddC.LBL. Experimenters Notebook Files (ENB Directory) -------------------------------------------- Experimenters Notebook files are e-mail messages and other notes collected during and shortly after data acquisition. They document expectations of various measurements and anomalies discovered in subsequent analysis. File names have the form ENByyddd.TXT, where yy is the two-digit year and ddd is the three-digit day-of-year. In general the messages in file ENByyddd.TXT refer to activities on that date regardless of when the message was sent. These are ASCII files with variable length records. Each record is delimited by an ASCII carriage-return line-feed pair. Earth Orientation Parameter Files (EOP Directory) --------------------------------------------------- Earth Orientation Parameter files were produced by the Time and Earth Motion Precision Observation (TEMPO) Group at JPL. They documented and predicted Earth rotation (rate and axis). These are ASCII files of variable length records. Each record is delimited by an ASCII line-feed (ASCII 10). File names have the form ydddzeee.EOP where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, z is the one-digit year of the last data, and eee is the day-of-year of the last data in the file. EOP files were typically released on Tuesdays and Fridays. There are both 'long' and 'short' versions. The long file covered past motion since about 1962 and a prediction for about three months into the future; these files have typical sizes of 860 kB. The short file covered the most recent nine months of past motion and a prediction for three months into the future; these files are typically 30 kB. Each EOP file is accompanied by a PDS minimal label with file name ydddzeee.LBL. Engineering Packet Data Files (EPK Directory) --------------------------------------------------- Engineering Packet Data files were produced by the MGS query server, operating on telemetry packets stored in the MGS Central Data Base (CDB). These are binary files, usually representing the collection of raw spacecraft engineering data received from a 24 hour period; they are not readily interpretable by end users. File names have the form ydddeeeC.EPK where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. Each EPK file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. File sizes can be as large as 100 MB. NB: No EPK files were collected during MOI. Filtered Body Rate Files (FBR Directory) --------------------------------------------------- Filtered Body Rate Files were created at Stanford from body rate data in the spacecraft engineering telemetry stream. They give spacecraft attitude as a function of time. FBR files are PDS TABLE objects; each is fully described as to format and content by a detached PDS label. File names are of the form ydddeeeC.FBR where y is the one-digit year of the first data, ddd is the three-digit day-of-year of the first data, eee is the three-digit day-of-year of the last data, and C is a character denoting sequence when more than one file with the same ydddeee is handled. File sizes vary depending on the time interval covered. FBR files were created during MGS Cruise to support gravitational wave experiments (GWE); as of the end of MOI, there was no plan to generate them to support MOI analyses. NB: No FBR files were collected during MOI. GEODYN Trajectory Files (GDN Directory) --------------------------------------------------- GEODYN SPK files were quick look orbit reconstructions produced by the MOLA Precise Orbit Determination Team. They were used for preliminary analysis of MOLA data and some radio occultations. These files give spacecraft and planetary ephemerides and are identical in format to SPK files (see below) by the MGS NAV Team. Files with ORIGINAL_PRODUCT_ID including 'qlnn' were based on the following gravity models: ql15 mgm0989a ql16 mgm0989c ql17 gmm2b (with no one-way Doppler daya) ql18 gmm2b (with one-way Doppler data if available) These are ASCII files of variable length records in a special NAIF 'transfer' format. Each record is delimited by a carriage-return (ASCII 13) line-feed (ASCII 10) pair, which may need to be removed before the file is used on the local machine. After delimiter conversion (if needed) the file would ordinarily be passed through the NAIF utility SPACIT or TOBIN to convert it to the local binary format. File names have the form ydddeeeC.GDN where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. Each GDN file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. Typical file sizes are less than 5 MB. GEODYN Trajectory Files (GDF Directory) --------------------------------------------------- GDF files are the same as GDN files (above) except that they are considered 'final' versions of the orbits. File names end with the .GDF suffix. NB: No GDF files were collected during MOI. Daily Health Report Files (HEA Directory) --------------------------------------------------- Daily Health Report Files were created at Stanford; they summarize spacecraft engineering data of interest for Radio Science, list recently acquired radio data, summarize any analysis performed on recent radio data, summarize anomalies in recent radio science operations, and list files that have been obtained from the MGS CDB or other sources. Daily Health Report Files are PDS TEXT objects; each has an attached PDS label. File names are of the form HEAydddC.TXT where y is the one-digit year of the report, ddd is the three-digit day-of-year of the report, and C is a character denoting sequence when more than one file with the same ydddeee is generated. The first report on a day would be HEAydddA.TXT; subsequent revisions or updates would be HEAydddB.TXT, HEAydddC.TXT, etc. Some Health Reports are accompanied by plots, saved as Type 1 PostScript files. File names for these plot files have names of the form HEAydddC.PSn where y and ddd are as defined above and n is the figure number. Each PostScript file should be accompanied by a detached PDS label, but that requirement was met only once in the MOI data set. The label file has name HEAydddC.LBL, meaning that the value of n is limited to 1 for any single health report. Both Health Reports themselves and accompanying PostScript files have variable length records delimited by carriage- return (ASCII 13) line-feed (ASCII 10) pairs. Ionosphere Calibration Files (ION Directory) --------------------------------------------------- Ionosphere Calibration files were produced by the Tracking System Analytic Calibration (TSAC) Group at JPL. They documented and predicted Earth ionospheric conditions. These are ASCII files of variable length records. Each record is delimited by an ASCII line-feed (ASCII 10). File names have the form ydddeeeC.ION where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. ION files were usually released at one week intervals to cover a single month; ydddeeeA.ION would be the file released during the first week, ydddeeeB.ION would be the file released during the second week, etc. Each ION file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. Typical file sizes are less than 50 kB. Light Time Files (LIT Directory) --------------------------------------------------- Light Time files were produced by the MGS Navigation Team (NAV). They gave radio propagation time from the spacecraft to Earth vs time. These are ASCII files of fixed length records. Each record is delimited by an ASCII carriage-return (ASCII 13) line-feed pair (ASCII 10), which may need to be converted to either or before the file is used on the local machine. File names have the form ydddeeeC.LIT where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. Each LIT file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. Typical file sizes are less than 1 MB. Channelized DSN Monitor Data Files (MCH Directory) --------------------------------------------------- Channelized DSN Monitor Data files were produced by the MGS query server, operating on DSN Monitor packets stored in the MGS Central Data Base (CDB). These are binary files, usually representing the collection of DSN Monitor data received from a 24 hour period; they are not readily interpretable by end users. File names have the form ydddeeeC.MCH where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. Each MCH file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. File sizes can be as large as 30 MB. In general, an MCH file can be derived from the corresponding MPK file using MGS-provided software and a decommutation map. Monitor data are collected according to MST (Monitor Sample Time) measured in UTC. Also in some MCH directories are ASCII tables of extracted channel values--channelized state vectors, or CSV files. These are values for a limited number of potentially useful MCH channels that have been saved in tabular form. CSV files in the MCH directory have names of the form CSVydddC.MCH where y, ddd, and C are the same as for the corresponding MCH file. Each CSV file is accompanied by a detached PDS label with name CSVydddC.LBL which completely describes the format and content of the CSV file. NB: Stanford is no longer able to process binary MCH files; see note above at the end of the section 'Files in the CALIB Directory' for details. Maneuver Implementation/Reconstruction Files (MIF Directory) --------------------------------------------------- Maneuver Implementation/Reconstruction files were produced by the MGS Spacecraft Team (SCT); they documented spacecraft maneuver events. These are ASCII files of variable length records. Each record is delimited by an ASCII line-feed (ASCII 10). File names have the form ydddeeeC.MIF where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. Each MIF file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. Typical file sizes are 2327 bytes. Maneuver Performance Data Files (MPD Directory) --------------------------------------------------- Maneuver Performance Data files were produced by the MGS Spacecraft Team (SCT). They contain estimates of spacecraft mass and center of mass; moments of inertia; thruster locations, directions, and magnitudes; and propellant flow rate. These are ASCII files of variable length records. Each record is delimited by an ASCII line-feed (ASCII 10). File names have the form ydddeeeC.MPD where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. Each MPD file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. Typical file sizes are 4 kB. Maneuver Profile Files (MPF Directory) --------------------------------------------------- Maneuver Profile Files were produced by the MGS Navigation Team (NAV). They are generic descriptions of orbit adjustments used by MGS during aerobraking. These are ASCII files of variable length records. Each record is delimited by a carriage-return (ASCII 13) line-feed (ASCII 10) pair. File names have the form XnnnDDCC.MPF where X is a character, nnn is a 3-digit number, DD indicates the adjustment direction ('UP' or 'DN'), and CC indicates the sequence if there is more than one file with the same XnnnDD. CC starts from 'AA'. Each MPF is accompanied by a PDS minimal label with file name XnnnDDCC.LBL. Typical file sizes are less than 700 bytes. DSN Monitor Packet Data Files (MPK Directory) --------------------------------------------------- DSN Monitor Packet Data files were produced by the MGS query server, operating on DSN Monitor packets stored in the MGS Central Data Base (CDB). Monitor data are records of DSN status and radio measurements. These are binary files, data received from a 24 hour period; they are not readily interpretable by end users. File names have the form ydddeeeC.MPK where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. Each MPK file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. File sizes can be as large as 30 MB. NB: No MPK files were collected during MOI. Orbit Propagation and Time Generation Files (OPT Directory) --------------------------------------------------- Orbit Propagation and Time Generation files were produced by the MGS Navigation Team (NAV). They contain estimates of event timing (e.g., equator crossings) that depend on precise knowledge of the spacecraft orbit. These are ASCII files of variable length records. Each record is delimited by an ASCII line-feed (ASCII 10). File names have the form ydddeeeC.OPT where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. Each OPT file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. Typical file sizes are less than 100 kB. Typical OPT files during MOI included one day of orbit reconstructions followed by several days of orbit predictions. Solar Array Kernel Files (SAK Directory) --------------------------------------------------- Solar Array Kernel files were produced by the MGS Spacecraft Team (SCT). They give the attitude of each solar array panel as a function of time. These are ASCII files of variable length records in a special NAIF 'transfer' format. Each record is delimited by a carriage-return (ASCII 13) line-feed (ASCII 10) pair, which may need to be removed before the file is used on the local machine. After delimiter conversion (if needed) the file would ordinarily be passed through the NAIF utility SPACIT or TOBIN to convert it to the local binary format. File names have the form ydddeeeC.TCK where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. Each TCK file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. Typical file sizes are less than 5 MB. Space Flight Operation Schedule Files (SFO Directory) --------------------------------------------------- Space Flight Operations Schedule Files were produced by the MGS Mission Control Team (MCT), usually in parallel with a corresponding Sequence of Events (SOE) file. They graphically present parts of the SOE. These are ASCII files of variable length records in a special format that allows use with the MGS-provided sfosedt program. Each record is delimited by a carriage-return (ASCII 13) line-feed (ASCII 10) pair, which may need to be removed before the file is used on the local machine. File names have the form ydddeeeC.SFO where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. Each SFO file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. Typical file sizes are less than 100 kB. NB: No SFO files were produced after 1998-08-20. Sequence of Events Files (SOE Directory) --------------------------------------------------- Sequence of Events Files were produced by the MGS Mission Control Team (MCT). These are ASCII files of variable length records. Until 1998-08-20 SOE files were produced in a special format that allowed use with the MGS-provided soeedt program. After 1998-08-20, files were produced in a straight ASCII format that required no special software; these may be identified by the '.tsoe' suffix in the ORIGINAL_PRODUCT_ID. Each record is delimited by a carriage-return (ASCII 13) line-feed (ASCII 10) pair, which may need to be removed before the file is used on the local machine. File names have the form ydddeeeC.SOE where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. Each SOE file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. Typical file sizes are less than 1 MB. Spacecraft/Planetary Ephemeris (SPK) Files (SPK Directory) --------------------------------------------------- Spacecraft/Planetary Ephemeris Files (also known as SP kernels or SPK files) were produced by the MGS Navigation Team (NAV). These files give spacecraft and planetary ephemerides. These are ASCII files of variable length records in a special NAIF 'transfer' format. Each record is delimited by a carriage-return (ASCII 13) line-feed (ASCII 10) pair, which may need to be removed before the file is used on the local machine. After delimiter conversion (if needed) the file would ordinarily be passed through the NAIF utility SPACIT or TOBIN to convert it to the local binary format. File names have the form ydddeeeC.SPK where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. Each SPK file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. Typical file sizes are less than 5 MB. Typical SPK files during MOI included one day of orbit reconstructions followed by several days of orbit predictions. Spacecraft Attitude (CK) Files (TCK Directory) --------------------------------------------------- Spacecraft Attitude Files (also known as C kernels or CK files) were produced by the MGS Spacecraft Team (SCT). These are ASCII files of variable length records in a special NAIF 'transfer' format. Each record is delimited by a carriage-return (ASCII 13) line-feed (ASCII 10) pair, which may need to be removed before the file is used on the local machine. After delimiter conversion (if needed) the file would ordinarily be passed through the NAIF utility SPACIT or TOBIN to convert it to the local binary format. File names have the form ydddeeeC.TCK where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. Each TCK file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. Typical file sizes are less than 5 MB. Troposphere Calibration Files (TRO Directory) --------------------------------------------------- Troposphere Calibration files were produced by the Tracking System Analytic Calibration (TSAC) Group at JPL. They documented and predicted Earth tropospheric conditions. These are ASCII files of variable length records. Each record is delimited by an ASCII line-feed (ASCII 10). File names have the form ydddeeeC.TRO where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and C is a character denoting sequence when more than one file with the same ydddeee is handled. C starts from 'A' and progresses to 'B', 'C', etc. with increasing numbers of similar coverage files. TRO files were typically released at the beginning of a month and covered the previous month. Each TRO file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. Typical file sizes are less than 50 kB. UltraStable Oscillator Files (USO Directory) -------------------------------------------- UltraStable Oscillator (USO) files are calibration data derived from open-loop radio measurments. Files are PDS table objects with detached labels. Examples include USO Allan Deviation (type A files) and the piecewise-continuous linear model of USO frequency (type M files). File names are of the form USOtyddd.TAB, where t is the file type (see above), y is the one-digit year in which the file was created, and ddd is the three-digit day-of-year in which the file was created. Each USO file is accompanied by a detached PDS label with name USOtyddd.LBL which completely describes the content and format of the file. DSN Weather Files (WEA Directory) --------------------------------------------------- DSN Weather files were produced by the Tracking System Analytic Calibration (TSAC) Group at JPL. Files give weather calibration information for DSN complexes. These are ASCII files of variable length records. Each record is delimited by an ASCII line-feed (ASCII 10). File names have the form ydddeeeD.WEA where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, eee is the day-of-year of the last data in the file, and D is a single digit denoting the DSN complex at which the data were acquired ('1' for Goldstone, '4' for Canberra, or '6' for Madrid). WEA files were typically released weekly and contain all weather data for the complex since 1 January. Each WEA file is accompanied by a PDS minimal label with file name ydddeeeC.LBL. The files grow at the rate of approximately 90 kB per month. Coordinate System : SPK ephemeris files and TCK files were produced for the J2000 inertial reference frame until the second orbit after Mars Orbit Insertion, when the TCK files were referenced to the Mars Mean Equator frame. SAK files presumably follow the same format as TCK files. NAIF reader routines may be used to convert these to other coordinate systems. Other data types are not dependent on definition of a coordinate system. Software : Software for parsing, reducing, and analyzing data such as these has been developed at Stanford University and elsewhere. Because such software must usually operate at the bit-level and is written for a narrow range of platforms, it is not suitable for general distribution. No software is included with this archival data set. Media/Format : The archival data set is written on CD-WO media using the Young Minds CD Studio or Yamaha/GEAR authoring system. The CD-WO volumes conform to ISO 9660 standards.
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| DATA_SET_RELEASE_DATE |
1999-09-08T00:00:00.000Z
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| START_TIME |
1997-09-02T12:00:00.000Z
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| STOP_TIME |
1999-03-08T12:00:00.000Z
|
| MISSION_NAME |
MARS GLOBAL SURVEYOR
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| MISSION_START_DATE |
1994-10-12T12:00:00.000Z
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| MISSION_STOP_DATE |
2007-09-30T12:00:00.000Z
|
| TARGET_NAME |
MARS
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| TARGET_TYPE |
PLANET
|
| INSTRUMENT_HOST_ID |
MGS
|
| INSTRUMENT_NAME |
RADIO SCIENCE SUBSYSTEM
|
| INSTRUMENT_ID |
RSS
|
| INSTRUMENT_TYPE |
RADIO SCIENCE
|
| NODE_NAME |
Geosciences
|
| ARCHIVE_STATUS |
ARCHIVED
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| CONFIDENCE_LEVEL_NOTE |
Overview : Data in this archival data set have been processed as part of health monitoring activities of the MGS Radio Science Team. In general, this is a good data set. Review : This archival data set was reviewed by the MGS Radio Science Team prior to submission to the Planetary Data System (PDS). The MGS Science Data Validation Team (SDVT) set standards and procedures. Prior to creation of the final version of the archival data set, key elements of the archive were distributed for preliminary review. These included electronic versions of example PDS labels, CATALOG files, and Software Interface Specifications. These materials were distributed to PDS personnel, the experiment investigator, and others, as appropriate. ODR files on the CD-WO volumes were checked using Stanford parsing and reduction software to ensure that they were both complete and accurate replicas of the data contained in the original files. Data Coverage and Quality : Significant events for Radio Science during MGS MOI were as follows. AB-1 and AB-2 stand for Aerobraking Phases I and II, respectively. TMO was the Transition to Mapping Orbit subphase of MOI. YY/DDD Start DSP Stop DSP Comments ------ -------- -------- ---------------- 97/252 14:00:00 15:12:11 Pressurization 97/255 01:31:12 01:57:07 MOI Burn and Occultation 97/296 First periapsis LGA recording 98/024 19:15:36 19:32:15 First AB-1 occultation recording 98/076 13:19:18 (ET) Close Phobos approach (380 km) 98/087 02:44:09 First SPO-1 periapsis gravity pass 98/088 01:51:00 02:15:00 First egress recording (LGA) 98/107 23:01:28 23:18:00 Last good ingress recording 98/118 15:52:00 16:33:00 Last AB-1 occultation recording 98/119 Begin solar conjunction period 98/147 End solar conjunction period 98/289 08:52:48 09:27:50 First AB-2 occultation recording 98/365 09:35:00 09:55:00 Last AB-2 occultation recording 99/035 09:36:00 Begin Gravity Calibration Orbits 99/035 16:27:00 16:34:00 First TMO occultation 99/059 20:00:00 Last GCO orbit 99/067 20:01:00 20:14:00 Last TMO occultation Quality of data was affected by anomalous conditions. Examples include: Open-Loop (ODR) Data Anomalies ------------------------------ a) 2-6 dB lower carrier-to-noise level at SPC 60 antennas throughout the occultation period (98/024-98/339) b) 'Sawtooth' frequency residuals in approximately 10 percent of the AB-1 data, less frequently in AB-2 data, and infrequently in TMO data (all stations) c) Amplitude baseline variations more than +/-0.1 dB (various) d) Spurs (occasional, no consistent pattern) e) Unreliable POCA (wrong SPA-R software) (SPC 60, 98/084-98/106) f) Poor frequency predictions because of inaccurate orbits during AB-2 (all stations; scattered, 98/289-98/365) g) Uplink ramping and telemetry ON during ingress occultations (99/035-99/067) h) HGA deployment. Bad data; various causes (99/087-99/094) i) Solar conjunction with severe plasma effects superposed on the radio signals (98/119-98/147) Closed-Loop Data Anomalies (mostly observed in ODF) --------------------------------------------------- Thermal sensitivity of USO observed during one-way tracking. Solar conjunction with severe plasma effects superposed on the radio signals (98/119-98/147) Note that the official beginning of the Orbit Insertion Phase has been defined as 1999-09-12; when this data set was assembled, the beginning date was understood to be 1999-09-02. Thus, the first few volumes in this data set include files which properly belong in the MGS-M-RSS-1-CRU-V1.0 data set. Limitations : The limitations in this data set follow from the quality of the execution, which is described above under Data Coverage and Quality.
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| CITATION_DESCRIPTION |
Tyler, G.L., G. Balmino, D.P. Hinson, W.L. Sjogren, D.E. Smith, R. Woo, J.W. Armstrong, F.M. Flasar, and R.A. Simpson, Mars Global Surveyor Raw Data Set - MOI V1.0, MGS-M-RSS-1-MOI-V1.0, NASA Planetary Data System, 1999.
|
| ABSTRACT_TEXT |
This data set contains archival raw, partially processed, and ancillary/supporting radio science data acquired during the Mars Orbit Insertion (MOI) phase of the Mars Global Surveyor (MGS) mission. The radio observations were carried out using the MGS spacecraft and Earth-based receiving stations of the NASA Deep Space Network (DSN). The observations were designed to test the spacecraft radio system, the DSN ground system, and MGS operations procedures; to be used in generating high-resolution gravity field models of Mars; and for estimating density and structure of the Mars atmosphere. Of most interest are likely to be the Orbit Data File and Original Data Record files, in the ODF and ODR directories, respectively, which provided the raw input to gravity and atmospheric investigations. The MOI phase extended from September 1997 to March 1999. On orbits 203-266 and 343-571 (approximately April and June-September 1998, respectively) the spacecraft periapsis was especially low giving the highest per-orbit sensitivity to gravity anomalies during the entire mission. Data were organized in approximately chronological order and delivered on a set of 159 CD volumes at the rate of 2-3 CD's per week. Typical volume of a one-day ODF was 300-400 kB. Typical volume of an ODR was 5-10 MB, and there could be multiple ODR's per day depending on DSN schedules and observing geometry.
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| PRODUCER_FULL_NAME |
RICHARD A. SIMPSON
G. LEONARD TYLER
F. FLASAR
R. WOO
DAVID SMITH
G. BALMINO
D. HINSON
WILLIAM SJOGREN
J. ARMSTRONG
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| SEARCH/ACCESS DATA |
Geosciences Web Services
Atmospheres Online Archives
Geosciences Online Archives
MGS Home Page
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