PDS_VERSION_ID = "PDS3" FILE_NAME = "JGMRO_120D_SHB.DAT" RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 512 FILE_RECORDS = 1674566 ^SHBDR_HEADER_TABLE = ("JGMRO_120D_SHB.DAT",1) ^SHBDR_NAMES_TABLE = ("JGMRO_120D_SHB.DAT",2) ^SHBDR_COEFFICIENTS_TABLE = ("JGMRO_120D_SHB.DAT",231) ^SHBDR_COVARIANCE_TABLE = ("JGMRO_120D_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 = "JGMRO_120D_SHB" PRODUCT_RELEASE_DATE = 2017-03-15 DESCRIPTION = " This file contains the covariance and related data for the JPL Mars gravity field MRO120D, a 120th degree and order spherical harmonic model. It is the second archived JPL gravity field that includes Mars Reconnaissance Orbiter (MRO) tracking data. The summary of radio tracking data this gravity field is as follows: MGS Gravity Calibration Orbit (GCO) including fixed high-gain antenna mapping 1999-02-02 to 1999-03-29 Mapping Orbit (MAP) 1999-03-29 to 2006-09-23 Note: This solution contains all useful MGS data prior to loss of contact with the spacecraft in Nov., 2006. Odyssey Transition Orbit (ODYT) 2002-01-11 to 2002-01-15 Mapping Orbit (ODYM) 2002-02-11 to 2015-01-03 MRO Transition Orbit (MROT) 2006-08-30 to 2006-09-11 Mapping Orbit (MROM) 2006-09-11 to 2015-04-30 Pathfinder 1997-07-04 to 1997-10-07 Viking 1 Lander 1976-07-21 to 1982-11-13 MER Opportunity Lander 2012-01-02 to 2012-05-02 Some details describing this model are: The spherical harmonic coefficients are fully normalized. The reference radius = 3396.0 km The prime meridian of this model is defined by the longitude of the Viking 1 Lander qqual to -47.95137 deg. The Mars System GM (Mars+Phobs+Deimos) = 42828.3758078 +- 0.0002 km^3/sec^2 The GM of Mars = 42828.3750104 km^3/sec^2 The GM of Phobos = (7.11 +- 0.05)x10^-4 km^3/sec^2 The GM of Deimos = (9.46 +- 1.23)x10^-5 km^3/sec^2 The Viking and Mariner 9 orbiter data are not included in this delivery unlike some past deliveries which included this data. This data do not seem to add any more information for the gravity although there is some Phobos and Deimos GM information in the data. The values for the Phobos and Deimos GM given here do not include the Viking and Mariner 9 orbiter data. The Mars-fixed reference frame is given by Konopliv et al. (2006) except with updated orientation parameters that are either estimated in the MRO120D solution or fixed to chosen values. The prime meridian of the MRO120D coordinate was chosen so that it agrees with the prime mreidian of the IAU 2000 coordinate frame to about 1.6 meters. The rotation from the body-fixed position rBF to the inertial postion rIN is: rIN = Rz(-N) Rx(-J) Rz(-PSI) Rx(-I) Rz(-PHI) rBF where N is the angle in the plane of the Earth-mean-equator of J2000 (EME2000) from the vernal equinox (intersection of the mean ecliptic and EME2000 planes) to the intersection of the Mars-mean-orbit of J2000 and EME2000 planes; J is the inclination of the Mars-mean-orbit plane relative to the EME2000 plane; PSI is the angle in the Mars-mean-orbit plane from the intersection of the EME2000 and Mars-mean-orbit planes to the intersection of the Mars-mean-orbit and Mars-true-equator of date planes; I is the inclination of the Mars-true-equator relative to the Mars-mean-orbit plane; PHI is the angle in the plane of the Mars-true-equator from the intersection of the Mars-mean-orbit plane and Mars-true-equator to the Mars prime meridian. PSI, I, and PHI have J2000 epoch and secular values plus corrections for nuations. PHI in addition has seasonal corrections for spin. For example, PSI = PSI(t=J2000) + (dPSI/dt)*T + dPSI(nutations) where T is time past J2000 in days. For MRO120D, the values of the orientation angles are: N = 3.37919183 deg (fixed) J = 24.67682669 deg (fixed) PSI(t=J2000) = 81.9683988032 deg (estimated) dPSI/dt = -0.0000057863 deg/day (estimated) I(t=J2000) = 25.1893822930 deg (estimated) dI/dt = -0.000000001 deg/day (estimated) PHI(t=J2000) = 133.386276647 deg (fixed) dPHI/dt = 350.891985307 deg/day (estimated) The estimated seasonal spin amplitudes for PHI with periods equal to a Mars year, 1/2 year, 1/3 year, and 1/4 year and an epoch of Jan. 1999 are given by PHI( 1yr,cosine) = 481 milliarcseconds PHI( 1yr, sine) = -155 milliarcseconds PHI(1/2yr,cosine) = -103 milliarcseconds PHI(1/2yr, sine) = -93 milliarcseconds PHI(1/3yr,cosine) = -35 milliarcseconds PHI(1/3yr, sine) = -3 milliarcseconds PHI(1/4yr,cosine) = -10 milliarcseconds PHI(1/4yr, sine) = -8 milliarcseconds The number of radio tracking data (Doppler and range) observations for the various data blocks are as follows: MGS GCO at 370 km periapsis = 140,735 MGS MAP at 370 km periapsis = 8,344,113 Odyssey transistion at 200 km periapsis = 27,661 Odyssey mapping at 390 km periapsis = 12,574,331 Pathfinder on the Mars surface = 6,817 Viking Lander on the Mars surface = 14,156 MRO transition at 200 km periapsis = 72,127 MRO mapping at 250 km periapsis = 9,931,781 A kaula type power law constraint is applied to the spherical harmonics coefficients beginning at degree 80. The MRO120D constraint uses a similar taper as the constraint applied to MGS95J (see Fig. 5 of Konopliv et al., 2006), but begins at degree 80. The k2 Love number to use with this MRO120D solution is 0.169. The second degree harmonic coefficients do not include the permanent tide due to the Love number. This delivery is the Mars static gravity field. However, the gravity field varies due to the mass exchange between the polar caps and the Mars atmosphere. The major component of this effect can be included in the gravity field by adding the following correction to the normalized J3 gravity coefficient: dJ3 = 2.95870587408D-09 * sin W*(t-t0) where W is the Mars mean motion = 191.39 deg/yr and t-t0 = years past Jan 1, 1999. This reference for this gravity field is Konopliv et al., An improved JPL Mars gravity field and orientation from Mars orbiter and lander tracking data, Icarus 274, 253-260, 2016. 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 MRO120D is delivered in the Spherical Harmonics Gravity Binary Data Record (SHGBDR) and is produced by the MRO Gravity Science Team at JPL under the direction of Alex Konopliv. " START_TIME = 2006-08-30T18:00:00.000 STOP_TIME = 2015-04-30T16:00:00.000 PRODUCT_CREATION_TIME = 2015-07-09T00:00:00.000 PRODUCER_FULL_NAME = "ALEX S. KONOPLIV" PRODUCER_INSTITUTION_NAME = "JET PROPULSION LABORATORY" PRODUCT_VERSION_TYPE = "FINAL" PRODUCER_ID = "MRO GST" SOFTWARE_NAME = "SHBGRV.V1.0" /* 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 = PC_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 = PC_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 = PC_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 = LSB_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 = LSB_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 = LSB_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 = LSB_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 = PC_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 = PC_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 = 9213 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 = 9213 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 = PC_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 = 42444291 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 = PC_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