PDS_VERSION_ID = "PDS3" FILE_NAME = "GMM3_120_SHB.DAT" RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 512 FILE_RECORDS = 1674338 ^SHBDR_HEADER_TABLE = ("GMM3_120_SHB.DAT",1) ^SHBDR_NAMES_TABLE = ("GMM3_120_SHB.DAT",2) ^SHBDR_COEFFICIENTS_TABLE = ("GMM3_120_SHB.DAT",231) ^SHBDR_COVARIANCE_TABLE = ("GMM3_120_SHB.DAT",460) INSTRUMENT_HOST_NAME = "MARS RECONNAISSANCE ORBITER" TARGET_NAME = "MARS" INSTRUMENT_NAME = "RADIO SCIENCE SUBSYSTEM" DATA_SET_ID = "MRO-M-RSS-5-SDP-V1.0" OBSERVATION_TYPE = "GRAVITY FIELD" PRODUCT_ID = "GMM-3" PRODUCT_RELEASE_DATE = 2016-01-21 DESCRIPTION = " This file contains the covariance and related data for the Mars gravity field GMM-3 that was derived at the NASA Goddard Space Flight Center using MRO, MGS, and Mars Odyssey radio tracking data. The GMM-3 model is a spherical harmonic solution of the static gravity field of Mars to degree and order 120. The radio tracking data included in this gravity solution are summarized as follows: MGS Science Phasing Orbit 1 (SPO-1) from 1998-03-27 to 1998-05-01 Science Phasing Orbit 2 (SPO-2) from 1998-05-28 to 1998-09-17 Gravity Calibration Orbit (GCO) from 1999-02-04 to 1999-02-19 Mapping Orbit (MAP) from 1999-02-20 to 2006-01-04 Mars Odyssey Transition Orbit (ODYT) from 2002-01-11 to 2002-01-15 Mapping Orbit (ODYM) from 2002-02-20 to 2014-11-05 MRO Transition Orbit (MROT) from 2006-08-30 to 2006-09-23 Mapping Orbit (MROM) from 2006-12-26 to 2015-03-30 The reference system for this solution is described by KONOPLIVETAL2006, published in Icarus with the DOI number 10.1016/j.icarus.2005.12.025. Note that it is *NOT* the IAU system for Mars. The reference radius for this model is 3396.0 km. The modeling of the gravity field of Mars also includes the time-varying geopotential that accounts for the redistribution of mass associated with the CO2 seasonal cycle. The time variations were modeled with the relation Ak coswt + Bk sin wt, where t is defined as days elapsed since January 01, 2000 00:00 UT. The cosine and sine amplitudes of the periodic functions for C20, C30, C40, and C50 were adjusted with this solution. The time-dependent function of this gravity harmonic coefficients is described in detail by Genova et al. (2016). The retrieved Ak and Bk coefficients of these zonal harmonic coefficients are as follows: annual semi-annual tri-annual (k=1) (k=2) (k=3) A B A B A B C20 2.39E-09 -0.83E-09 1.23E-09 0.73E-09 0.53E-09 0.46E-09 C30 1.67E-09 2.35E-09 0.32E-09 0.21E-09 0.13E-09 0.15E-09 C40 0.85E-10 -1.56E-10 0.35E-10 -0.24E-10 -0.51E-10 -0.64E-10 C50 0.38E-09 1.30E-09 0.15E-09 0.42E-09 0.32E-09 -0.02E-09 In addition, the GM and Mars k2 Love Number were estimated with this solution. The new values from GMM-3 are: GM = 0.4282837285418775E+05 km**3/s**2; sigma-GM = 0.162E-04 km**3/s**2 k2 = 0.1697; sigma-k2 = 0.9E-03 The uncertainties for k2 and GM are formal values. We recommend a calibration factor of 3 for the uncertainties to obtain conservative error estimates. The reference for the GMM-3 gravity field is GENOVAETAL2016. This file is a set of four tables: a header table, a names table, a coefficients table, and a covariance table. Definitions of the tables follow. The formal error covariance of GMM-3 is delivered in the Spherical Harmonics Gravity Binary Data Record (SHGBDR) and is produced at NASA GSFC. References ---------- For this solution: GENOVAETAL2016. Other pertinent references: Mars Reference System: ---------------------- Konopliv, A. S., Yoder, C.F., Standish, E. M., Yuan, D.-N., and W. L. Sjogren, A global solution for the Mars static and seasonal gravity, Mars orientation,Phobos and Deimos masses, and Mars ephemeris, Icarus, 182, pp. 23-50, 2006. Mars Atmospheric Modeling: -------------------------- Bruinsma, S., and F. G. Lemoine, A preliminary semiempirical thermosphere model of Mars: DTM-Mars. J. Geophys. Res.: Planets (1991-2012) 107, 15-1. Genova, A., Goossens, S., Lemoine, F. G., Mazarico, E., Fricke, S. K., Smith, D. E., and M.T. Zuber, Long-term variability of CO2 and O in the Mars upper atmosphere from MRO radio science data, J. Geophys. Res.: Planets 120, 849-868." START_TIME = 1998-03-27T08:00:00.000 STOP_TIME = 2015-03-30T04:00:00.000 PRODUCT_CREATION_TIME = 2016-01-21T17:00:00.000 PRODUCER_FULL_NAME = "ANTONIO GENOVA" PRODUCER_INSTITUTION_NAME = "NASA/GODDARD SPACE FLIGHT CENTER" PRODUCT_VERSION_TYPE = "FINAL" PRODUCER_ID = "MRO GST" SOFTWARE_NAME = "VCE" /* Structure Objects */ OBJECT = SHBDR_HEADER_TABLE ROWS = 1 COLUMNS = 9 ROW_BYTES = 56 INTERCHANGE_FORMAT = BINARY DESCRIPTION = "The SHBDR Header includes descriptive information about the spherical harmonic coefficients which follow in SHBDR_COEFFICIENTS_TABLE. The header consists of a single record of nine data columns requiring 56 bytes. The Header is followed by a pad of binary integer zeroes to ensure alignment with RECORD_BYTES." OBJECT = COLUMN NAME = "REFERENCE RADIUS" DATA_TYPE = IEEE_REAL START_BYTE = 1 BYTES = 8 UNIT = "KILOMETER" DESCRIPTION = "The assumed reference radius of the spherical planet." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "CONSTANT" DATA_TYPE = IEEE_REAL START_BYTE = 9 BYTES = 8 UNIT = "N/A" DESCRIPTION = "For a gravity field model the gravitational constant GM in kilometers cubed per seconds squared for the planet. For a topography model, set to 1" END_OBJECT = COLUMN OBJECT = COLUMN NAME = "UNCERTAINTY IN CONSTANT" DATA_TYPE = IEEE_REAL START_BYTE = 17 BYTES = 8 UNIT = "N/A" DESCRIPTION = "For a gravity field model the uncertainty in the gravitational constant GM in kilometers cubed per seconds squared for the planet. For a topography model, set to 0." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "DEGREE OF FIELD" DATA_TYPE = MSB_INTEGER START_BYTE = 25 BYTES = 4 UNIT = "N/A" DESCRIPTION = "Degree of the model field." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ORDER OF FIELD" DATA_TYPE = MSB_INTEGER START_BYTE = 29 BYTES = 4 UNIT = "N/A" DESCRIPTION = "Order of the model field." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "NORMALIZATION STATE" DATA_TYPE = MSB_INTEGER START_BYTE = 33 BYTES = 4 UNIT = "N/A" DESCRIPTION = "The normalization indicator. For gravity field: 0 coefficients are unnormalized 1 coefficients are normalized 2 other." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "NUMBER OF NAMES" DATA_TYPE = MSB_INTEGER START_BYTE = 37 BYTES = 4 UNIT = "N/A" DESCRIPTION = "Number of valid names in the SHBDR Names Table. Also, the number of valid coefficients in the SHBDR Coefficients Table." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "REFERENCE LONGITUDE" POSITIVE_LONGITUDE_DIRECTION = "EAST" DATA_TYPE = IEEE_REAL START_BYTE = 41 BYTES = 8 UNIT = "DEGREE" DESCRIPTION = "The reference longitude for the spherical harmonic expansion; normally 0." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "REFERENCE LATITUDE" DATA_TYPE = IEEE_REAL START_BYTE = 49 BYTES = 8 UNIT = "DEGREE" DESCRIPTION = "The reference latitude for the spherical harmonic expansion; normally 0." END_OBJECT = COLUMN END_OBJECT = SHBDR_HEADER_TABLE OBJECT = SHBDR_NAMES_TABLE ROWS = 14637 COLUMNS = 1 ROW_BYTES = 8 INTERCHANGE_FORMAT = BINARY DESCRIPTION = "The SHBDR Names Table contains names for the solution parameters (including gravity field coefficients) which will follow in SHBDR_COEFFICIENTS_TABLE. The order of the names in SHBDR_NAMES_TABLE corresponds identically to the order of the parameters in SHBDR_COEFFICIENTS_TABLE. Each coefficient name is of the form Cij or Sij where i is the degree of the coefficient and j is the order of the coefficient. Both indices are three- digit zero-filled right-justified ASCII character strings (for example, C010005 for the 10th degree 5th order C coefficient, or S002001 for the 2nd degree 1st order S coefficient). The eighth byte in the table is an ASCII blank used to ensure that the row length is equal to RECORD_BYTES. Names of other solution parameters are limited to 8 ASCII characters; if less than 8, they will be left-justified and padded with ASCII blanks. The Names Table itself will be padded with ASCII blanks, if necessary, so that its length is an integral multiple of RECORD_BYTES." OBJECT = COLUMN NAME = "PARAMETER NAME" DATA_TYPE = CHARACTER START_BYTE = 1 BYTES = 8 UNIT = "N/A" DESCRIPTION = "The name of the coefficient or other solution parameter, left- justified and padded with ASCII blanks (if needed) to 8 characters." END_OBJECT = COLUMN END_OBJECT = SHBDR_NAMES_TABLE OBJECT = SHBDR_COEFFICIENTS_TABLE ROWS = 14637 COLUMNS = 1 ROW_BYTES = 8 INTERCHANGE_FORMAT = BINARY DESCRIPTION = "The SHBDR Coefficients Table contains the coefficients and other solution parameters for the spherical harmonic model. The order of the coefficients in this table corresponds exactly to the order of the coefficient and parameter names in SHBDR_NAMES_TABLE. The SHBDR Coefficients Table will be padded with double precision DATA_TYPE zeroes so that its total length is an integral multiple of RECORD_BYTES." OBJECT = COLUMN NAME = "COEFFICIENT VALUE" DATA_TYPE = IEEE_REAL START_BYTE = 1 BYTES = 8 UNIT = "N/A" DESCRIPTION = "A coefficient Cij or Sij or other solution parameter as specified in the SHBDR Names Table." END_OBJECT = COLUMN END_OBJECT = SHBDR_COEFFICIENTS_TABLE OBJECT = SHBDR_COVARIANCE_TABLE ROWS = 107128203 COLUMNS = 1 ROW_BYTES = 8 INTERCHANGE_FORMAT = BINARY DESCRIPTION = "The SHBDR Covariance Table contains the covariances for the spherical harmonic model coefficients and other solution parameters. The order of the covariances in this table is defined as columnwise vector storage of the upper triangular matrix formed by the product of the SHBDR Names Table with its transpose. For example, if the Names Table has four entries A, B, C, and D, then the covariances are given by the column vectors in the upper triangular matrix of | A | [ A B C D ] = | AA AB AC AD | | B | | BA BB BC BD | | C | | CA CB CC CD | | D | | DA DB DC DD | That is, the covariance table will list (in this order) AA, AB, BB, AC, BC, CC, AD, BD, CD, and DD. The SHBDR Covariance Table will be padded with double precision DATA_TYPE zeroes so that its total length is an integral multiple of RECORD_BYTES." OBJECT = COLUMN NAME = "COVARIANCE VALUE" DATA_TYPE = IEEE_REAL START_BYTE = 1 BYTES = 8 UNIT = "N/A" DESCRIPTION = "The covariance value for the coefficients and other solution parameters specified by the product of SHBDR_NAMES_TABLE with its transpose, after omitting redundant terms." END_OBJECT = COLUMN END_OBJECT = SHBDR_COVARIANCE_TABLE END