urn:nasa:pds:mess_rs_derived:data:ggmes_20v02_shb 1.0 1.11.0.0 Product_Observational 2018-07-05 1.0 PDS4 migrated product. 2008-01-07Z 2011-08-23Z MESSENGER Mission urn:nasa:pds:context:investigation:mission.messenger data_to_investigation MESSENGER Spacecraft urn:nasa:pds:context:instrument_host:spacecraft.mess is_instrument_host Radio Science Subsystem Instrument urn:nasa:pds:context:instrument:rss.mess is_instrument Mercury Planet urn:nasa:pds:context:target:planet.mercury data_to_target SHBDR shbgrv;v1.0 ggmes_20v02_shb.dat 2011-09-15 This file contains coefficients 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 binary 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 Binary Data Record (SHBDR). It has been produced by the MESSENGER Radio Science at NASA GSFC, and extends to degree and order 20. A Kaula rule of 1.25E-05/L^2 was applied. Data up to August 23rd, 2011 are included in the solution. The model was published in Science in April 2012 by Smith et al. (doi:10.1126/science.1218809). SHBDR Header Table 0 1 The SHBDR Header includes descriptive information about the spherical harmonic coefficients that 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. 9 0 56 reference radius 1 1 IEEE754MSBDouble 8 km The assumed reference radius of the spherical planet. constant 2 9 IEEE754MSBDouble 8 For a gravity field model the gravitational constant GM in km cubed per second squared for the planet. For a topography model, set to 1. uncertainty in constant 3 17 IEEE754MSBDouble 8 For a gravity field model the uncertainty in the gravitational constant GM in km cubed per second squared for the planet. For a topography model, set to 0. degree of field 4 25 SignedMSB4 4 Degree of the model field. order of field 5 29 SignedMSB4 4 Order of the model field. normalization state 6 33 SignedMSB4 4 The normalization indicator. For gravity field: 0 coefficients are unnormalized 1 coefficients are normalized 2 other. number of names 7 37 SignedMSB4 4 Number of valid names in the SHBDR Names Table. Also, the number of valid coefficients in the SHBDR Coefficients Table. reference longitude 8 41 IEEE754MSBDouble 8 degree Reference longitude for the spherical harmonic expansion; normally 0. reference latitude 9 49 IEEE754MSBDouble 8 degree Reference latitude for the spherical harmonic expansion; normally 0. SHBDR Names Table 512 437 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 8 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. 1 0 8 parameter name 1 1 ASCII_String 8 The name of the coefficient or other solution parameter, left- justified and padded with ASCII blanks (if needed) to 8 characters. SHBDR Coefficients Table 4096 437 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 zeroes. 1 0 8 coefficient value 1 1 IEEE754MSBDouble 8 A coefficient Cij or Sij or other solution parameter as specified in the SHBDR Names Table. SHBDR Covariance Table 7680 95703 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 by the product of the SHBDR Names Table with its transpose, except that redundant terms are omitted on their second occurrence. The SHBDR Covariance Table will be padded with double precision zeroes. 1 0 8 covariance value 1 1 IEEE754MSBDouble 8 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. ggmes_20v02_shb.lbl 0 PDS3 Original PDS3 label Carriage-Return Line-Feed