PDS_VERSION_ID = PDS3 RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 122 FILE_RECORDS = 1327 ^SHADR_HEADER_TABLE = ("ggmes_100v08_sha.tab",1) ^SHADR_COEFFICIENTS_TABLE = ("ggmes_100v08_sha.tab",3) INSTRUMENT_HOST_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" ORIGINAL_PRODUCT_ID = "HGM008.SHA" PRODUCT_ID = "HGM008.SHA" PRODUCT_RELEASE_DATE = 2019-03-15 DESCRIPTION = "This file contains coefficient and related data for a spherical harmonic model of the Hermean gravity field. Input data are from radio tracking of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. This product is a set of ascii tables: a header table, a names table, a coefficients table, and a covariance table. Definitions of the tables follow. This MESSENGER Mercury gravity model is in the form of a Spherical Harmonics Ascii Data Record (SHADR). It has been produced by the MESSENGER Radio Science at NASA GSFC, and extends to degree and order 100. A Kaula rule of 4.0E-05/L^2 was applied. All the MESSENGER tracking data, up to the end of mission (April 30, 2015) are included in this solution. Reference radius = 2440.0 km The pole orientation and spin period were adjusted during the gravity solution. Pole orientation (right ascension and declination at J2000): RA = 281.0082 degrees DEC = 61.4164 degrees Spin rate = 6.138505441 degrees/day . The prime meridian and secular terms in RA/DEC were not adjusted. Prime meridian = 329.7500 degrees (at J2000) RA rate = -0.0328 degree/century DEC rate = -0.0049 degree/century The citation for this model is GENOVAETAL2019." START_ORBIT_NUMBER = 1 STOP_ORBIT_NUMBER = 4104 START_TIME = 2008-01-07 STOP_TIME = 2015-04-30 PRODUCT_CREATION_TIME = 2019-03-15 PRODUCER_FULL_NAME = "ANTONIO GENOVA" PRODUCER_INSTITUTION_NAME = "GODDARD SPACE FLIGHT CENTER" PRODUCER_ID = "MESSENGER RS TEAM" SOFTWARE_NAME = "VCE" OBJECT = SHADR_HEADER_TABLE ROWS = 1 COLUMNS = 8 ROW_BYTES = 137 ROW_SUFFIX_BYTES = 107 INTERCHANGE_FORMAT = ASCII DESCRIPTION = "The SHADR header includes descriptive information about the spherical harmonic coefficients which follow in SHADR_COEFFICIENTS_TABLE. The header consists of a single record of eight (delimited) data columns requiring 137 bytes, a pad of 105 unspecified ASCII characters, an ASCII carriage-return, and an ASCII line-feed." OBJECT = COLUMN NAME = "REFERENCEADIUS" DATA_TYPE = ASCII_REAL START_BYTE = 1 BYTES = 23 FORMAT = "E23.16" UNIT = "KILOMETER" DESCRIPTION = "The assumed reference radius of the spherical planet." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "CONSTANT" DATA_TYPE = ASCII_REAL START_BYTE = 25 BYTES = 23 FORMAT = "E23.16" UNIT = "N/A" DESCRIPTION = "For a gravity field model the assumed gravitational constant GM in km 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 = ASCII_REAL START_BYTE = 49 BYTES = 23 FORMAT = "E23.16" UNIT = "N/A" DESCRIPTION = "For a gravity field model the uncertainty in the gravitational constant GM in km cubed per second squared for the planet (or, set to 0 if not known). For a topography model, set to 0." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "DEGREE OF FIELD" DATA_TYPE = ASCII_INTEGER START_BYTE = 73 BYTES = 5 FORMAT = "I5" UNIT = "N/A" DESCRIPTION = "Degree of the model field." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ORDER OF FIELD" DATA_TYPE = ASCII_INTEGER START_BYTE = 79 BYTES = 5 FORMAT = "I5" UNIT = "N/A" DESCRIPTION = "Order of the model field." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "NORMALIZATION STATE" DATA_TYPE = ASCII_INTEGER START_BYTE = 85 BYTES = 5 FORMAT = "I5" 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 = "REFERENCE LONGITUDE" POSITIVE_LONGITUDE_DIRECTION = "EAST" DATA_TYPE = ASCII_REAL START_BYTE = 91 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "The reference longitude for the spherical harmonic expansion; normally 0." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "REFERENCE LATITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 115 BYTES = 23 FORMAT = "E23.16" UNIT = "DEGREE" DESCRIPTION = "The reference latitude for the spherical harmonic expansion; normally 0." END_OBJECT = COLUMN END_OBJECT = SHADR_HEADER_TABLE OBJECT = SHADR_COEFFICIENTS_TABLE ROWS = 5150 COLUMNS = 6 ROW_BYTES = 107 ROW_SUFFIX_BYTES = 15 INTERCHANGE_FORMAT = ASCII DESCRIPTION = "The SHADR coefficients table contains the coefficients for the spherical harmonic model. Each row in the table contains the degree index m, the order index n, the coefficients Cmn and Smn, and the uncertainties in Cmn and Smn. The (delimited) data require 107 ASCII characters; these are followed by a pad of 13 unspecified ASCII characters, an ASCII carriage-return, and an ASCII line-feed." OBJECT = COLUMN NAME = "COEFFICIENT DEGREE" DATA_TYPE = ASCII_INTEGER START_BYTE = 1 BYTES = 5 FORMAT = "I5" UNIT = "N/A" DESCRIPTION = "The degree index m of the C and S coefficients in this record." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "COEFFICIENT ORDER" DATA_TYPE = ASCII_INTEGER START_BYTE = 7 BYTES = 5 FORMAT = "I5" UNIT = "N/A" DESCRIPTION = "The order index n of the C and S coefficients in this record." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "C" DATA_TYPE = ASCII_REAL START_BYTE = 13 BYTES = 23 FORMAT = "E23.16" UNIT = "N/A" DESCRIPTION = "The coefficient Cmn for this spherical harmonic model." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "S" DATA_TYPE = ASCII_REAL START_BYTE = 37 BYTES = 23 FORMAT = "E23.16" UNIT = "N/A" DESCRIPTION = "The coefficient Smn for this spherical harmonic model." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "C UNCERTAINTY" DATA_TYPE = ASCII_REAL START_BYTE = 61 BYTES = 23 FORMAT = "E23.16" UNIT = "N/A" DESCRIPTION = "The uncertainty in the coefficient Cmn for this spherical harmonic model." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "S UNCERTAINTY" DATA_TYPE = ASCII_REAL START_BYTE = 85 BYTES = 23 FORMAT = "E23.16" UNIT = "N/A" DESCRIPTION = "The uncertainty in the coefficient Smn for this spherical harmonic model." END_OBJECT = COLUMN END_OBJECT = SHADR_COEFFICIENTS_TABLE END