PDS_VERSION_ID = "PDS3" FILE_NAME = "JGMESS_160AV01_SHB.DAT" RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 512 FILE_RECORDS = 5249815 ^SHBDR_HEADER_TABLE = ("JGMESS_160AV01_SHB.DAT",1) ^SHBDR_NAMES_TABLE = ("JGMESS_160AV01_SHB.DAT",2) ^SHBDR_COEFFICIENTS_TABLE = ("JGMESS_160AV01_SHB.DAT",407) ^SHBDR_COVARIANCE_TABLE = ("JGMESS_160AV01_SHB.DAT",812) SPACECRAFT_NAME = "MESSENGER" TARGET_NAME = "MERCURY" INSTRUMENT_NAME = "RADIO SCIENCE SUBSYSTEM" DATA_SET_ID = "MESS-H-RSS/MLA-5-SDP-V1.0" OBSERVATION_TYPE = "GRAVITY FIELD" PRODUCT_ID = "JGMESS_160AV01_SHB" PRODUCT_RELEASE_DATE = 2019-07-30 DESCRIPTION = " This file contains the covariance and related data for the JPL Mercury gravity field MESS160A, a 160th degree and order spherical harmonic model. It is the first archived JPL gravity field that includes MESSENGER tracking data. Some details describing this model are: The spherical harmonic coefficients are fully normalized. The reference radius = 2440.0 km The Mercury-fixed reference frame is given by the IAU right ascension (RA) and declination (DEC) coordinate system with the following values for the angles and rate. Parameters estimated together with the gravity field are noted as well as those held fixed. RA = 281.0138 +/- 0.0025 deg (estimated) dRA/dt = -0.0328 deg/cty (fixed) DEC = 61.4161 +/- 0.0017 deg (estimated) dDEC/dt = -0.0049 deg/cty (fixed) W0 = 329.75 deg (fixed) dW/dt = 6.138514 +/- 0.000006 deg/day (estimated) A kaula power law constraint is applied to the spherical harmonics coefficients for all harmonic degrees as 5x10^-5 /n^2. The k2 Love number to use with this MESS160A solution is 0.53. The second degree harmonic coefficients do not include the permanent tide due to the Love number. This reference for this gravity field is Konopliv et al., The Mercury gravity field, orientation, Love number, and ephemeris from the MESSENGER radiometric tracking data, Icarus 335, 253-260, 2020, https://doi.org/10.1016/j.icarus.2019.07.020. The formal error covariance of MESS160A is delivered in the Spherical Harmonics Gravity Binary Data Record (SHGBDR) and is produced at JPL by Alex Konopliv. " START_TIME = 2011-03-18T06:00:00.000 STOP_TIME = 2015-04-30T00:02:00.000 PRODUCT_CREATION_TIME = 2019-07-30T00:00:00.000 PRODUCER_FULL_NAME = "ALEX S. KONOPLIV" PRODUCER_INSTITUTION_NAME = "JET PROPULSION LABORATORY" PRODUCT_VERSION_TYPE = "FINAL" PRODUCER_ID = "JPL GRAVITY SCIENCE" 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 = 25918 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 = 25918 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 = 335884321 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