Data Set Information
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MARS GLOBAL SURVEYOR RAW DATA SET - CRUISE V1.0
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MGS-M-RSS-1-CRU-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 proposed see [TYLERETAL1992]. This data set was collected while the spacecraft was en route from Earth to Mars (the MGS Cruise Phase); it can serve as calibration for later Mars observations. During Cruise, the spacecraft was far from other bodies, so evolution of its trajectory was very smooth. Range and Doppler behavior could be predicted long in advance, and variability resulted from intrinsic limitations of the equipment (including unmodeled spacecraft activity) -- not from the phenomena being measured. Some of the Cruise data have intrinsic science value of their own. Approximately halfway through Cruise, three weeks of spacecraft and ground system time was devoted to a search for gravitational waves, presumably originating outside the solar system. Two types of measurements were conducted during Cruise; these are known as closed-loop and open-loop recordings. The closed- loop system uses a phase-lock loop in the receiver to track the downlink signal, reporting both amplitude and frequency at intervals typically of once per second. In the open-loop system, the signal is simply converted to a baseband frequency range; the entire passband is 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 Cruise. Relevant questions would include the measurement uncertainties in range and Doppler at different DSN antennas; these would set constraints on any model of Mars' gravity field developed later, for example. Users of ODRs could identify and characterize anomalous signals within the recorded passband, derive the drift of the USO during Cruise, and calculate Allan Deviation for various radio science configurations. Data collected during the Gravitational Wave Experiment could be searched for evidence of gravitational waves. Parameters : The ATDF is the primary output from the closed-loop system. Its format and content changed on 15 April 1997. ATDFs generated before 15 April had 117 defined fields in the data records; ATDFs generated beginning on 15 April had 150 fields, though not all had been assigned. Though the general nature of the ATDF parameters in the new version remained the same -- status flags, Doppler residuals, range measurements, signal strength estimates, etc. -- the scope of the measurements and their accuracies improved considerably. 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 types include: High- or low-rate Doppler Uplink phase Differential Range vs Integrated Doppler (DRVID) Range Allan deviation Smoothed noise High or low-rate downlink 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. Like the ATDF, its format and content were also upgraded effective 15 April 1997. Each ODF is accompanied by a full PDS label which describes both the content and format of the associated file. ODF data types 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 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 JPL Radio Metric Data Conditioning Team (RMDCT). ODFs are abstracted from subsets of ATDF data. The open-loop format delivered to Stanford is usually the ODS (packet data). In some cases where the Ground Data System (GDS) corrupted the ODS during delivery (or lost it entirely), data have been recovered from tape in ODR format. ODS packets have been converted to ODR format for consistency in subsequent processing and archive; headers applied by GDS for ODS handling have not been preserved. The resultant ODR (whether from ODS conversion or from backup tape) accurately represents 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. Files which were delayed in delivery to Stanford may be out of order, however. Users should consult listings in the INDEX/CUMINDEX.TAB file to ascertain full coverage of each file type. ATDFs were delivered irregularly during MGS Cruise; a full set is not available. ATDFs were obtained for most USO tests and during the Gravitational Wave Experiment (GWE) in late April and early May 1997. 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. Typical ATDF file sizes are 39 Mbytes. ODFs were issued approximately daily throughout MGS Cruise; in some cases special ODFs were also created. Most of the ODFs which were released are included in the archival data set. ODFs are stored in the ODF directory. File names are of the form ydddeeeC.ODF 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. In most cases ydddeeeB.ODF is NOT simply a revised version of ydddeeeA.ODF; there were many requests for special ODF processing during MGS Cruise -- 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 were two files had the same nominal ydddhhmm (for example, two DSN stations began recording at the same time), 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 where three files had the same ydddhhmm, the less significant mm digit was converted to 'K', 'M', etc. For data collected during MGS Cruise, multiple ydddhhmm instances occurred primarily from multiple queries for the same data, or from early data obtained as ODS and later data obtained as ODR from tape backup. The PDS label has file name ydddhhmm.LBL. At 5000 samples per second, a two-hour USO 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 GWE 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 was not represented on a CD-WO volume, the corresponding directory was omitted. With the exception of files stored in the CALIB directory, ancillary files appeared 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 are 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. Planetary Constants files are 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 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 are 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. Only four Decommutation Map files were used during MGS Cruise. DCSM515A.SRC and DCOM515A.BIN were the source and binary maps, respectively, for DSN Monitor 5-15 data. DCSSCR14.SRC and DCOSCR14.BIN were the source and binary maps, respectively, for spacecraft engineering data. 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. Angular Momentum Desaturation Files (AMD Directory) --------------------------------------------------- Angular Momentum Desaturation files are produced by the MGS Spacecraft Team (SCT). Each 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 are 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. Engineering Channelized Data Summary Files (ECS Directory) --------------------------------------------------- Engineering Channelized Summary Data Files are 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 ydddeeeA.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. 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. Alternatively, the characters yyddd may be used to indicate very tersely the subject matter of a collection of messages. 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 are produced by the Time and Earth Motion Precision Observation (TEMPO) Group at JPL. They document and predict 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 are typically released on Tuesdays and Fridays. There are both 'long' and 'short' versions. The long file covers 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 covers 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 are 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. 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. 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. 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 are produced by the Tracking System Analytic Calibration (TSAC) Group at JPL. They document and predict 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. Frequently, ION files are 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 are produced by the MGS Navigation Team (NAV). They give 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 are 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. 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. Maneuver Implementation/Reconstruction Files (MIF Directory) --------------------------------------------------- Maneuver Implementation/Reconstruction files are produced by the MGS Spacecraft Team (SCT); they document 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 are 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. DSN Monitor Packet Data Files (MPK Directory) --------------------------------------------------- DSN Monitor Packet Data files are 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, 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.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. Orbit Propagation and Time Generation Files (OPT Directory) --------------------------------------------------- Orbit Propagation and Time Generation files are 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 1 MB. Space Flight Operation Schedule Files (SFO Directory) --------------------------------------------------- Space Flight Operations Schedule Files are produced by the MGS Mission Control Team (MCT), usually in parallel with a corresponding Sequence of Event (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. Sequence of Event Files (SOE Directory) --------------------------------------------------- Sequence of Event Files are produced by the MGS Mission Control Team (MCT). These are ASCII files of variable length records in a special format that allows use with the MGS-provided soeedt 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.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) are 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. Spacecraft Attitude (CK) Files (TCK Directory) --------------------------------------------------- Spacecraft Attitude Files (also known as C kernels or CK files) are 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 are produced by the Tracking System Analytic Calibration (TSAC) Group at JPL. They document and predict 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 are typically released at the beginning of a month and cover 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 are 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 are 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. 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 authoring system. The CD-WO volumes conform to ISO 9660 standards.
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| DATA_SET_RELEASE_DATE |
1997-12-31T00:00:00.000Z
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| START_TIME |
1996-11-06T12:00:00.000Z
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| STOP_TIME |
1997-09-02T12:00:00.000Z
|
| 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
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| TARGET_NAME |
MARS
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| TARGET_TYPE |
PLANET
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| INSTRUMENT_HOST_ID |
MGS
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| INSTRUMENT_NAME |
RADIO SCIENCE SUBSYSTEM
|
| INSTRUMENT_ID |
RSS
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| INSTRUMENT_TYPE |
RADIO SCIENCE
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| NODE_NAME |
Geosciences
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| 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 Cruise were as follows: YY/DDD Start DSP Stop DSP Comments ------ -------- -------- ---------------- 96/326 15:22:00 16:53:00 TCM-1 96/332 04:46:00 07:00:25 USO Test #1 96/345 10:00:00 12:00:00 USO Test #2 (no open-loop data) 96/353 10:00:00 12:00:00 USO Test #3 (no open loop data) 97/009 Switch from LGT to HGA 97/016 06:30:00 08:30:00 USO Test #4 97/030 10:00:00 12:00:00 USO Test #5 97/043 12:45:00 14:45:00 USO test #6 (tape data only) 97/049 19:01:27 21:01:27 USO test #7 97/061 12:31:50 16:31:51 USO test #8 (4 hrs) 97/072 11:32:16 13:32:16 USO Test #9 97/088 04:19:36 07:19:36 KaBLE/USO test 97/092 05:57:30 07:00:00 USO Test #10 (1 hr; DSP error) 97/104 Begin GWE 97/124 End GWE 97/126 (approx) S/C enters safe mode 97/142 (approx) S/C exits safe mode 97/162 02:00:00 04:00:00 USO test #11 97/189 14:00:00 20:30:00 RS ORT #1 97/193 20:30:00 02:10:00 RS ORT #2 97/198 00:10:39 02:10:39 USO Test #12 97/204 22:00:00 04:30:00 RS ORT #3 97/220 05:15:00 11:45:00 RS ORT #4 97/220 14:00:00 16:00:00 USO Test #13 97/224 00:40:00 12:35:00 RS ORT #5 97/237 12:00:00 01:00:00 TCM-4 Quality of data was affected by anomalous conditions. Examples include: Open-Loop (ODR) Data Anomalies ------------------------------ 1. Presence of 60 and/or 180 Hz spurs around carrier 2. Presence of 30, 420, 540 Hz and higher spurs (infrequent) 3. 650 Hz carrier sidebands (present when telemetry is ON) 4. Missing data records (frequent) 5. Amplitude modulation on various time scales of a few seconds and longer; modulation with a period of about 33 secs was common unless spacecraft activities had been largely limited to radio science support 6. Amplitude modulation with 100 minute period (resulting from spacecraft spin while in Cruise) 7. Incorrect POCA values and/or POCA values out of sequence(common) 8. Small spurs at 30, 48, 75 Hz from carrier (uncommon) 9. Incorrect attenuator settings, DSP configuration (uncommon) 10. Image of carrier in power spectra (common at 200 sps sampling rate) 11. Spikes in frequency residuals at 209 sec intervals (when ranging ON) 12. 60 Hz comb in power spectra, tracking carrier (seen once) Closed-Loop Data Anomalies (mostly observed in ODF) --------------------------------------------------- 1. Interference from Goldstone Solar System Radar (infrequent) 2. Discontinuities among range results at different stations 3. Excessive Doppler noise in DSS 45 data Note that the official end of the Cruise Phase has been defined as 1997-09-12; when this data set was assembled, the end date was understood to be 1997-09-02. If a complete understanding of Cruise data is required, users may wish to investigate the first few volumes in the MGS-M-RSS-1-MOI-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.
|
| CITATION_DESCRIPTION |
Simpson, R. A., MARS GLOBAL SURVEYOR RAW DATA SET - CRUISE V1.0, MGS-M-RSS-1-CRU-V1.0, NASA Planetary Data System, 1997
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| ABSTRACT_TEXT |
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 proposed see [TYLERETAL1992].
|
| PRODUCER_FULL_NAME |
RICHARD A. SIMPSON
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| SEARCH/ACCESS DATA |
Geosciences Web Services
Atmospheres Online Archives
Geosciences Online Archives
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