PDS_VERSION_ID = PDS3 RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 688 FILE_RECORDS = 601 ^BSR_GEOM_HDR_TABLE = ("9132S00A.SRG",1) ^BSR_GEOM_TABLE = ("9132S00A.SRG",2) INSTRUMENT_HOST_NAME = "MARS GLOBAL SURVEYOR" TARGET_NAME = "MARS" INSTRUMENT_NAME = "RADIO SCIENCE SUBSYSTEM" DATA_SET_ID = "MGS-M-RSS-5-SDP-V1.0" PRODUCT_ID = "9132S00A.SRG" START_TIME = 1999-05-12T18:00:00 STOP_TIME = 1999-05-12T18:10:00 ORIGINAL_PRODUCT_ID = "9066154B.IPN" PRODUCT_CREATION_TIME = 2000-09-14T20:19:27 DESCRIPTION = "This file summarizes observing geometry for Mars Global Surveyor (MGS) bistatic radar (BSR) observations. The results apply to both atmospheric occultations and surface scattering, but more parameters of interest for surface studies have been included. The keywords for start and stop time (above) are Earth Receive Time (ERT). The file comprises two tables. The first table is a single row which identifies the calculation (fingerprints). The second table (with many rows) is the geometry summary itself. File names are of the form ydddHmmC.SRG where y is the one-digit year, ddd is the 3-digit day-of-year, H is a letter denoting the hour (A=00, B=01, ..., X=23), and mm is the 2-digit minute of the first data in the file. C indicates version of the file; C='A' is the first version, 'B' is the second version, etc. ydddHmm in these files is intended to be SIMILAR to ydddHmm in TPS and TPH occultation file names and in SRT and SRI surface scattering file names. However, because SRG files are produced independently, this correspondence cannot be guaranteed. Further, mm in the other files can sometimes include a letter -- if data were collected simultaneously at two antennas; and the version indicators (C) may be entirely different. This file was produced by Dick Simpson of the MGS Radio Science Team (RST) as part of his Participating Scientist investigation." OBJECT = BSR_GEOM_HDR_TABLE NAME = "BSR GEOMETRY HEADER" INTERCHANGE_FORMAT = ASCII ROWS = 1 COLUMNS = 7 ROW_BYTES = 77 ROW_SUFFIX_BYTES = 611 DESCRIPTION = "Table contains identifying information and constants for use with the geometry in the next table. Table contains a single row of 7 columns giving DSN antenna number, input SPK file name, assumed planet radius and speed of light, latitude and longitude of a user-specified target point, and time spacing of rows in next table. Columns are delimited by commas; total space occupied by data columns and delimiters is 75 bytes. The row is padded with 611 ASCII blanks. An ASCII carriage-return and line-feed occupy byte positions 687 and 688." OBJECT = COLUMN COLUMN_NUMBER = 1 NAME = "DSS" DATA_TYPE = ASCII_INTEGER START_BYTE = 1 BYTES = 2 FORMAT = "I2" DESCRIPTION = "Deep Space Network antenna number." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 2 NAME = "SPK FILE NAME" DATA_TYPE = CHARACTER START_BYTE = 5 BYTES = 12 DESCRIPTION = "File name of the SPK file used to generate the geometry data in the BSR GEOMETRY table. File name is of the form ydddeeeC.EXT where y is the least significant digit in the year, ddd is the start day-of-year for the SPK data, eee is end day-of-year for the SPK data, C denotes the version of the SPK file ('A' is first, 'B' is second, etc.), and EXT is one of several possible extensions: SPK standard MGS NAV Team SPK file GDN quick-look Goddard reconstruction GDF final Goddard reconstruction IPN reconstruction by JPL IPNG The ydddeeeC.EXT naming convention was adopted by the MGS RST to simplify tracking of SPK files; the original product ID be found in the detached label for the SPK file itself." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 3 NAME = "RP" DATA_TYPE = ASCII_REAL START_BYTE = 19 BYTES = 12 FORMAT = "F12.3" UNIT = "METER" DESCRIPTION = "Assumed radius for spherical planet. Note that partial derivatives with respect to Rp are given for many important quantities, so the assumption of a single radius is not as restrictive as it might first seem." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 4 NAME = "VLITE" DATA_TYPE = ASCII_REAL START_BYTE = 32 BYTES = 14 FORMAT = "F14.3" UNIT = "METER PER SECOND" DESCRIPTION = "Assumed speed of light in vacuum." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 5 NAME = "TLAT" DATA_TYPE = ASCII_REAL START_BYTE = 47 BYTES = 9 FORMAT = "F9.4" UNIT = "DEGREE" DESCRIPTION = "Planetocentric latitude of user-specified target point. This point may or may not be meaningful for a given application. It was included to facilitate planning and analysis for spotlight mode surface scattering experiments." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 6 NAME = "TLON" DATA_TYPE = ASCII_REAL START_BYTE = 57 BYTES = 9 FORMAT = "F9.4" UNIT = "DEGREE" DESCRIPTION = "Planetocentric east longitude of user-specified target point. This point may or may not be meaningful for a given application. It was included to facilitate planning and analysis for spotlight mode surface scattering experiments." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 7 NAME = "DT" DATA_TYPE = ASCII_REAL START_BYTE = 67 BYTES = 9 FORMAT = "F9.3" UNIT = "SECOND" DESCRIPTION = "Time spacing between rows in next table." END_OBJECT = COLUMN END_OBJECT = BSR_GEOM_HDR_TABLE OBJECT = BSR_GEOM_TABLE NAME = "BSR GEOMETRY" INTERCHANGE_FORMAT = ASCII ROWS = 600 COLUMNS = 34 ROW_BYTES = 688 DESCRIPTION = "Table values allow reconstruction of bistatic observing geometry. The 34 columns give Earth receive time; transmit time; Mars fixed-body x, y, and z unit vectors; positions of spacecraft, DSN receiver, and various surface points (specular point, backscatter point, closest approach of occultation ray, and a user-specified target point); incidence, scattering, and bistatic angles at these points; and sensitivities of several quantities to changes in planet radius. The user-specified target point is given in areocentric latitude and longitude. Depending on the application, it may or may not be meaningful. For MGS, one such point might be the Mars Polar Lander target site. The backscatter point is where a line connecting the DSN receiver and the spacecraft intersects the planetary surface. At the backscatter point, the bistatic angle is zero. The backscatter point is only defined when the spacecraft appears silhouetted against the planet disk when viewed from the receiver on Earth (that is, when the planet surface appears to be behind the spacecraft). The raypath closest approach point is where a line connecting the receiver and spacecraft is closest to the planetary surface. This is the same construction as for the backscatter point. But the raypath closest approach point is defined only when the spacecraft is NOT silhouetted against the disk AND when the receiver-to-spacecraft distance is greater than the distance between the planet center of mass and the receiver. The specular point is where angle of incidence equals angle of reflection and where the incidence plane and the scattering plane are the same. When the spacecraft is in occultation, the specular point is not defined. Vectors are given in inertial (Earth mean equator of J2000) coordinates. Latitudes and longitudes are given in areocentric fixed body (rotating) coordinates. Values at Mars are given at transmit time; values at Earth are given at ERT. Mixed quantities (e.g., vector from spacecraft to DSN station) are combinations. Mars is assumed to be a sphere of radius (3397+3397+3375)/3 kilometers. Speed of light is assumed to be 299792458 m/s. This is an ASCII table. Columns and items are delimited by commas (vectors are considered to be single columns comprising three 'items'). Data and delimiters occupy the first 686 bytes of each row; rows are delimited by an ASCII carriage-return line-feed pair in byte positions 687 and 688." OBJECT = COLUMN COLUMN_NUMBER = 1 NAME = "TRX" DATA_TYPE = ASCII_INTEGER START_BYTE = 1 BYTES = 5 FORMAT = "I5" UNIT = SECOND DESCRIPTION = "Earth received time (ERT) for which the the geometrical calculations were made. TRX is the time (UTC) when an Earth-based observer would see this geometry. Given in seconds from midnight. For date, see START_TIME in the PDS label file." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 2 NAME = "TTX" DATA_TYPE = ASCII_REAL START_BYTE = 7 BYTES = 12 FORMAT = "F12.6" UNIT = SECOND DESCRIPTION = "Transmit time corresponding to TRX. The one-way light time for a photon traveling directly from the spacecraft to the DSN station has been subtracted from TRX." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 3 NAME = "NPOLE" DATA_TYPE = ASCII_REAL START_BYTE = 20 BYTES = 29 ITEMS = 3 ITEM_BYTES = 9 ITEM_OFFSET = 10 FORMAT = "F9.6" UNIT = "N/A" DESCRIPTION = "North Pole unit vector in J2000 coordinates." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 4 NAME = "FBODX" DATA_TYPE = ASCII_REAL START_BYTE = 50 BYTES = 29 ITEMS = 3 ITEM_BYTES = 9 ITEM_OFFSET = 10 FORMAT = "F9.6" UNIT = "N/A" DESCRIPTION = "Fixed body Mars x-axis unit vector in J2000 coordinates." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 5 NAME = "FBODY" DATA_TYPE = ASCII_REAL START_BYTE = 80 BYTES = 29 ITEMS = 3 ITEM_BYTES = 9 ITEM_OFFSET = 10 FORMAT = "F9.6" UNIT = "N/A" DESCRIPTION = "Fixed body Mars y-axis unit vector in J2000 coordinates." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 6 NAME = "DOD" DATA_TYPE = ASCII_REAL START_BYTE = 110 BYTES = 41 ITEMS = 3 ITEM_BYTES = 13 ITEM_OFFSET = 14 FORMAT = "E13.6" UNIT = "METER" DESCRIPTION = "Center of Mars to DSN vector at TRX in J2000 coordinates." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 7 NAME = "DOS" DATA_TYPE = ASCII_REAL START_BYTE = 152 BYTES = 41 ITEMS = 3 ITEM_BYTES = 13 ITEM_OFFSET = 14 FORMAT = "E13.6" UNIT = "METER" DESCRIPTION = "Center of Mars to spacecraft vector at TTX in J2000 coordinates." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 8 NAME = "DSD" DATA_TYPE = ASCII_REAL START_BYTE = 194 BYTES = 41 ITEMS = 3 ITEM_BYTES = 13 ITEM_OFFSET = 14 FORMAT = "E13.6" UNIT = "METER" DESCRIPTION = "Spacecraft (TTX) to DSN (TRX) vector in J2000 coordinates." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 9 NAME = "DOT" DATA_TYPE = ASCII_REAL START_BYTE = 236 BYTES = 41 ITEMS = 3 ITEM_BYTES = 13 ITEM_OFFSET = 14 FORMAT = "E13.6" UNIT = "METER" DESCRIPTION = "Vector from center of Mars to user-specified surface point in J2000 coordinates." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 10 NAME = "DTD" DATA_TYPE = ASCII_REAL START_BYTE = 278 BYTES = 41 ITEMS = 3 ITEM_BYTES = 13 ITEM_OFFSET = 14 FORMAT = "E13.6" UNIT = "METER" DESCRIPTION = "User-specified point (TTX) to DSN (TRX) vector in J2000 coordinates." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 11 NAME = "DTS" DATA_TYPE = ASCII_REAL START_BYTE = 320 BYTES = 41 ITEMS = 3 ITEM_BYTES = 13 ITEM_OFFSET = 14 FORMAT = "E13.6" UNIT = "METER" DESCRIPTION = "User-specified point to spacecraft vector at TTX in J2000 coordinates." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 12 NAME = "THTI" DATA_TYPE = ASCII_REAL START_BYTE = 362 BYTES = 9 FORMAT = "F9.6" UNIT = "DEGREE" DESCRIPTION = "Incidence angle at user-specified point. The angle between the local surface normal and the DTS vector. Values larger than 90 mean the spacecraft is below the horizon." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 13 NAME = "THTS" DATA_TYPE = ASCII_REAL START_BYTE = 372 BYTES = 9 FORMAT = "F9.6" UNIT = "DEGREE" DESCRIPTION = "Scattering angle at user-specified point. The angle between the local surface normal and the DTD vector. Values larger than 90 mean that the DSN receiving site below the horizon." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 14 NAME = "BETA" DATA_TYPE = ASCII_REAL START_BYTE = 382 BYTES = 9 FORMAT = "F9.6" UNIT = "DEGREE" DESCRIPTION = "Bistatic angle at user-specified point. Separation angle between DSN and the spacecraft as seen at the user-specified point. Angle between DTS and DTD." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 15 NAME = "DOB" DATA_TYPE = ASCII_REAL START_BYTE = 392 BYTES = 41 ITEMS = 3 ITEM_BYTES = 13 ITEM_OFFSET = 14 FORMAT = "E13.6" UNIT = "METER" DESCRIPTION = "Center of Mars to beta=0 (backscatter) point in J2000 coordinates. If the beta=0 point does not exist, this vector is undefined and BLAT and BLON should be set to -999.9999." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 16 NAME = "BLAT" DATA_TYPE = ASCII_REAL START_BYTE = 434 BYTES = 9 FORMAT = "F9.6" UNIT = "DEGREE" INVALID_CONSTANT = -999.9999 DESCRIPTION = "Areocentric latitude of beta=0 point. Set to -999.9999 if the point does not exist." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 17 NAME = "BLON" DATA_TYPE = ASCII_REAL START_BYTE = 444 BYTES = 9 FORMAT = "F9.6" UNIT = "DEGREE" INVALID_CONSTANT = -999.9999 DESCRIPTION = "Areocentric east longitude of beta=0 point. Set to -999.9999 if the point does not exist." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 18 NAME = "DOR" DATA_TYPE = ASCII_REAL START_BYTE = 454 BYTES = 41 ITEMS = 3 ITEM_BYTES = 13 ITEM_OFFSET = 14 FORMAT = "E13.6" UNIT = "METER" DESCRIPTION = "Center of Mars to raypath closest approach (RCA) point in J2000 coordinates. The raypath is vector DSD; the RCA point is on the surface of Mars where DSD is closest. If the RCA point does not exist, DOR is undefined and RLAT and RLON should be set to -999.9999." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 19 NAME = "RLAT" DATA_TYPE = ASCII_REAL START_BYTE = 496 BYTES = 9 FORMAT = "F9.6" UNIT = "DEGREE" INVALID_CONSTANT = -999.9999 DESCRIPTION = "Areocentric latitude of the raypath closest approach point. Set to -999.9999 if the spacecraft to DSN receiver distance is less than the DSN receiver to center of Mars distance." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 20 NAME = "RLON" DATA_TYPE = ASCII_REAL START_BYTE = 506 BYTES = 9 FORMAT = "F9.6" UNIT = "DEGREE" INVALID_CONSTANT = -999.9999 DESCRIPTION = "Areocentric east longitude of the raypath closest approach point. Set to -999.9999 if the spacecraft to DSN receiver distance is less than the DSN receiver to center of Mars distance." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 21 NAME = "DOP" DATA_TYPE = ASCII_REAL START_BYTE = 516 BYTES = 41 ITEMS = 3 ITEM_BYTES = 13 ITEM_OFFSET = 14 FORMAT = "E13.6" UNIT = "METER" DESCRIPTION = "Center of Mars to specular point vector in J2000 coordinates. If the specular point does not exist, this vector is undefined and PLAT and PLON should be set to -999.9999" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 22 NAME = "THPI" DATA_TYPE = ASCII_REAL START_BYTE = 558 BYTES = 9 FORMAT = "F9.6" UNIT = "DEGREE" DESCRIPTION = "Incidence angle at specular point. Values are undefined when the spacecraft is in occultation." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 23 NAME = "THPS" DATA_TYPE = ASCII_REAL START_BYTE = 568 BYTES = 9 FORMAT = "F9.6" UNIT = "DEGREE" DESCRIPTION = "Reflection angle at specular point. Values are undefined when the spacecraft is in occultation." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 24 NAME = "PLAT" DATA_TYPE = ASCII_REAL START_BYTE = 578 BYTES = 9 FORMAT = "F9.6" UNIT = "DEGREE" INVALID_CONSTANT = -999.9999 DESCRIPTION = "Areocentric latitude of specular point. Set to -999.9999 if the specular point does not exist (the spacecraft is in occultation)." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 25 NAME = "PLON" DATA_TYPE = ASCII_REAL START_BYTE = 588 BYTES = 9 FORMAT = "F9.6" UNIT = "DEGREE" INVALID_CONSTANT = -999.9999 DESCRIPTION = "Areocentric east longitude of specular point. Set to -999.9999 if the specular point does not exist (the spacecraft is in occultation)." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 26 NAME = "DTHTI" DATA_TYPE = ASCII_REAL START_BYTE = 598 BYTES = 9 FORMAT = "E9.2" UNIT = "DEGREE PER METER" DESCRIPTION = "Partial derivative of THTI with respect to Rp. The change in incidence angle at the user-specified target point resulting from a +1 m change in Mars radius." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 27 NAME = "DTHTS" DATA_TYPE = ASCII_REAL START_BYTE = 608 BYTES = 9 FORMAT = "E9.2" UNIT = "DEGREE PER METER" DESCRIPTION = "Partial derivative of THTS with respect to Rp. The change in scattering angle at the user-specified target point resulting from a +1 m change in Mars radius." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 28 NAME = "DBETA" DATA_TYPE = ASCII_REAL START_BYTE = 618 BYTES = 9 FORMAT = "E9.2" UNIT = "DEGREE PER METER" DESCRIPTION = "Partial derivative of BETA with respect to Rp. The change in bistatic angle at the user-specified target point resulting from a +1 m change in Mars radius." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 29 NAME = "DBLAT" DATA_TYPE = ASCII_REAL START_BYTE = 628 BYTES = 9 FORMAT = "E9.2" UNIT = "DEGREE PER METER" INVALID_CONSTANT = -9.99E-02 DESCRIPTION = "Partial derivative of BLAT with respect to Rp. The change in latitude of the backscatter point resulting from a +1 m change in Mars radius. Set to -9.99E-02 if there is no backscatter point (line from DSN station to spacecraft does not intersect the surface)." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 30 NAME = "DBLON" DATA_TYPE = ASCII_REAL START_BYTE = 638 BYTES = 9 FORMAT = "E9.2" UNIT = "DEGREE PER METER" INVALID_CONSTANT = -9.99E-02 DESCRIPTION = "Partial derivative of BLON with respect to Rp. The change in longitude of the backscatter point resulting from a +1 m change in Mars radius. Set to -9.99E-02 if there is no backscatter point (line from DSN station to spacecraft does not intersect the surface)." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 31 NAME = "DTHPI" DATA_TYPE = ASCII_REAL START_BYTE = 648 BYTES = 9 FORMAT = "E9.2" UNIT = "DEGREE PER METER" INVALID_CONSTANT = -9.99E-02 DESCRIPTION = "Partial derivative of THPI with respect to Rp. The change in incidence angle at the specular point resulting from a +1 m change in Mars radius. Set to -9.99E-02 if there is no specular point (spacecraft is in occultation)." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 32 NAME = "DTHPS" DATA_TYPE = ASCII_REAL START_BYTE = 658 BYTES = 9 FORMAT = "E9.2" UNIT = "DEGREE PER METER" INVALID_CONSTANT = -9.99E-02 DESCRIPTION = "Partial derivative of THPS with respect to Rp. The change in reflection angle at the specular point resulting from a +1 m change in Mars radius. Set to -9.99E-02 if there is no specular point (spacecraft is in occultation)." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 33 NAME = "DPLAT" DATA_TYPE = ASCII_REAL START_BYTE = 668 BYTES = 9 FORMAT = "E9.2" UNIT = "DEGREE PER METER" INVALID_CONSTANT = -9.99E-02 DESCRIPTION = "Partial derivative of PLAT with respect to Rp. The change in latitude of the specular point resulting from a +1 m change in Mars radius. Set to -9.99E-02 if there is no specular point (spacecraft is in occultation)." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 34 NAME = "DPLON" DATA_TYPE = ASCII_REAL START_BYTE = 678 BYTES = 9 FORMAT = "E9.2" UNIT = "DEGREE PER METER" INVALID_CONSTANT = -9.99E-02 DESCRIPTION = "Partial derivative of PLON with respect to Rp. The change in longitude of the specular point resulting from a +1 m change in Mars radius. Set to -9.99E-02 if there is no specular point (spacecraft is in occultation)." END_OBJECT = COLUMN END_OBJECT = BSR_GEOM_TABLE END