urn:nasa:pds:grail_gravity_derived:data_shbdr:jggrx_1800f_shb_l100 1.0 1.18.0.0 Product_Observational 2026-05-16 1.0 Initial PDS4 version 2012-03-01T16:28:00.000Z 2012-12-14T20:56:00.000Z 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 jggrx_1800f_shb_l100.dat 2024-07-18T00:00:00.000 This file contains the covariance and related data for the JPL Lunar gravity field GL1800F, a 1800th degree and order spherical harmonic model. It is a JPL gravity field that includes the entire primary mission (March 1, 16:30 to May 29, 16:36, 2012) and the entire extended mission GRAIL tracking data (August 30, 16:20 to Dec. 14, 20:56, 2012). This solution uses the version 4 level-1 data for the primary and extended missions. Some details describing this model are: The spherical harmonic coefficients are fully normalized. The reference radius = 1738.0 km The planetary ephemeris is de440 and defines the lunar body-fixed principal axes (PA) coordinate system. The second degree Love number solution is estimated to be k2=0.024223. The third degree Love number solution is estimated to be k3=0.0163. The second and third degree gravity coefficients of this model do not include the permanent tide. A constraint is applied starting at n=601. The a priori value is the topography from gravity coefficient value (i.e., not zero) and the a priori uncertainty equals 0.3 x the gravity from topography coefficient value using topography to power 23 and a variable density. The weighting of the KBRR data is 0.03 to 0.06 microns/sec for the primary mission and 0.05 microns/sec for the entire extended mission. This product contains the truncated n=100 covariance of the GL1800F gravity model or JGGRX_1800F_SHB_L100. The covariance is scaled to realistic uncertainties based upon differences with other solutions. This increases the uncertainties for degree 2 and 3 by a factor of 15 and decreases to 1 at degree 120. The covariance is generated from 2000 clones of GL1800F. Reference: R. S. Park, A. Berne, A. S. Konopliv, J. T. Keane, I. Matsuyama, F. Nimmo, M. Rovira-Navarro, M. P. Panning, M. Simons, D. J. Stevenson, R. C. Weber, 'Thermal asymmetry in the Moon's mantle inferred from monthly tidal response', Nature, 2025. 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 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. 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 The reference longitude for the spherical harmonic expansion; normally 0. Reference_Latitude 9 49 IEEE754LSBDouble 8 degree The reference latitude for the spherical harmonic expansion; normally 0. SHBDR_Names_Table 512 10198 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 82432 10198 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 164352 52004701 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. jggrx_1800f_shb_l100.lbl 0 PDS3 Original PDS3 label Carriage-Return Line-Feed