urn:nasa:pds:grail_gravity_derived:data_shbdr:gggrx_0660pm_shb_l420 1.1 1.18.0.0 Product_Observational 2023-05-24 1.1 Updated file comment regarding principal axis frame 2022-08-15 1.0 Initial PDS4 version 2012-03-01T16:28:00.000Z 2012-05-29T16:36:00.000Z Gravity Recovery and Interior Laboratory Mission urn:nasa:pds:context:investigation:mission.gravity_recovery_and_interior_laboratory data_to_investigation Gravity Recovery and Interior Laboratory A Host urn:nasa:pds:context:instrument_host:spacecraft.grail-a is_instrument_host Gravity Recovery and Interior Laboratory B Host urn:nasa:pds:context:instrument_host:spacecraft.grail-b is_instrument_host Lunar Gravity Ranging System A for GRAIL-A Instrument urn:nasa:pds:context:instrument:grail-a.lgrs-a is_instrument Lunar Gravity Ranging System B for GRAIL-B Instrument urn:nasa:pds:context:instrument:grail-b.lgrs-b is_instrument Moon Satellite urn:nasa:pds:context:target:satellite.earth.moon data_to_target gggrx_0660pm_shb_l420.dat 2013-10-21T00:00:00.000 This file contains coefficients and related data for the GSFC Lunar gravity field GRGM660PRIM, a degree and order 660 spherical harmonic model. It is a preliminary GSFC gravity field that includes the entire nominal mission of GRAIL tracking data (March 1, 16:30 to May 29, 16:36, 2012). Some details describing this model are: The spherical harmonic coefficients are fully normalized. The reference radius = 1738.0 km The planetary ephemeris is de421 and defines the lunar body-fixed coordinate system in the principal axes frame. A Kaula type power law constraint is applied to the spherical harmonics coefficients for degrees greater than 330 (2.5e-4/n^2). The weighting of the data is 0.05 microns/sec for the 5-s KBRR data and 0.12mm/s for the 10-s 2-way S-band DSN tracking data. The estimated tidal Love numbers are: k20 = 0.024165 +/- 0.000091 k21 = 0.023915 +/- 0.000013 k22 = 0.024852 +/- 0.000017 for an aggregate k2 = 0.02427 +/- 0.000054 k30 = 0.007342+/-0.001534 This product contains the truncated n=420 covariance of the GRGM660PRIM gravity model or GGGRX_0660PM_SHA. The reference for the GRGM660PRIM gravity field is LEMOINEETAL2013, published in the Journal of Geophysical Research with the DOI number 10.1002/jgre.20118. 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 GRAIL moon gravity model is in the form of a Spherical Harmonics Binary Data Record (SHBDR). 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 IEEE754LSBDouble 8 km The assumed reference radius of the spherical planet. Constant 2 9 IEEE754LSBDouble 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 IEEE754LSBDouble 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 SignedLSB4 4 Degree of the model field. Order_of_Field 5 29 SignedLSB4 4 Order of the model field. Normalization_State 6 33 SignedLSB4 4 The normalization indicator. For gravity field: 0 coefficients are unnormalized 1 coefficients are normalized 2 other. Number_of_Names 7 37 SignedLSB4 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 IEEE754LSBDouble 8 degree Reference longitude for the spherical harmonic expansion; normally 0. Reference_Latitude 9 49 IEEE754LSBDouble 8 degree Reference latitude for the spherical harmonic expansion; normally 0. SHBDR_Names_Table 512 177242 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 1418448 177242 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 IEEE754LSBDouble 8 A coefficient Cij or Sij or other solution parameter as specified in the SHBDR_Names_Table. SHBDR_Covariance_Table 2836384 15707451903 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 zeroes 1 0 8 Covariance_Value 1 1 IEEE754LSBDouble 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. gggrx_0660pm_shb_l420.lbl 0 PDS3 Original PDS3 label Carriage-Return Line-Feed