urn:nasa:pds:mgs-rss:data-sha:ggm2bc80 1.0 1.22.0.0 Product_Observational 2025 MGS RSS This file contains coefficients and related data for the spherical harmonic model GMM2B of the Mars gravity field. Input data are from radio tracking of the Mars Global Surveyor spacecraft. The coordinate system is IAU 1991 The data cover 1997-10-13T00:00:00Z to 2000-02-29T12:05:00Z. Frank Lemoine 1 Goddard Space Flight Center https://ror.org/0171mag52 David Smith 2 Goddard Space Flight Center https://ror.org/0171mag52 2025-02-12 1.0 This product, GGM2BC80.SHA, was originally released as part of the PDS3 MGS-M-RSS-5-SDP-V1.0 data set. The metadata have been migrated to PDS4. The data themselves are unchanged. 1997-10-13T00:00:00Z 2000-02-29T12:05:00Z Science Derived Mars Global Surveyor Spherical Harmonic Model ASCII Data Mars Global Surveyor Mission urn:nasa:pds:context:investigation:mission.mars_global_surveyor data_to_investigation Mars Global Surveyor Host urn:nasa:pds:context:instrument_host:spacecraft.mgs is_instrument_host Radio Science Subsystem (RSS) Instrument urn:nasa:pds:context:instrument:mgs.rss is_instrument Mars Planet urn:nasa:pds:context:target:planet.mars data_to_target 19 4375 urn:nasa:pds:mgs-rss:browse:ggm2bmea::1.0 data_to_browse urn:nasa:pds:mgs-rss:browse:ggm2bmwa::1.0 data_to_browse urn:nasa:pds:mgs-rss:browse:ggm2bpna::1.0 data_to_browse urn:nasa:pds:mgs-rss:browse:ggm2bpsa::1.0 data_to_browse urn:nasa:pds:mgs-rss:data-maps:ggm2ba60::1.0 data_to_derived_product urn:nasa:pds:mgs-rss:data-maps:ggm2be60::1.0 data_to_derived_product urn:nasa:pds:mgs-rss:data-maps:ggm2be70::1.0 data_to_derived_product urn:nasa:pds:mgs-rss:data-maps:ggm2be80::1.0 data_to_derived_product 10.1007/BF00051818 Davies, M. E., V. K. Abalakin, A. Brahic, M. Bursa, B.H. Chovitz, J. H. Lieske, P. K. Seidelmann, A. T. Sinclair, Y. S. Tjuflin, Report of the IAU/IAG/COSPAR Working Group on Cartographic Coordinates and Rotational Elements of the Planets and Satellites: 1991, Celestial Mechanics and Dynamical Astronomy, 53, 377-397, 1992. Coordinate System is IAU 1991. Kaula, W.M., Theory of Satellite Geodesy, Blaisdell, Waltham, MA, 1966. The gravity model was derived using a Kaula type constraint: sqrt(2)*13*10**(-5)/L**2 where L is the spherical harmonic degree. Without this constraint, the high degree terms develop excessive power. MGS-M-RSS-5-SDP-V1.0:GGM2BC80.SHA:GGM2BC80.SHA data_to_derived_source_product 10.17189/1519757 PDS Planetary Plasma Interactions Node This is the first version converted to PDS4. The DOI references the source PDS3 data set. GGM2BC80.SHA 2001-03-21T09:45:35 405040 632aa625ac817e630788a794b83da6f1 MGS Spherical Harmonic ASCII GMM2B Model Header 1997-10-13 - 2000-02-29 0 1 Carriage-Return Line-Feed 8 0 244 Reference Radius 1 1 ASCII_Real 23 The assumed reference radius of the spherical planet. Constant 2 25 ASCII_Real 23 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. Uncertainty in Constant 3 49 ASCII_Real 23 For a gravity field model the uncertainty in the gravitational constant GM in km cubed per seconds squared for the planet (or, set to 0 if not known). For a topography model, set to 0. Degree of Field 4 73 ASCII_Integer 5 deg of the model field. Order of Field 5 79 ASCII_Integer 5 Order of the model field. Normalization State 6 85 ASCII_Integer 5 The normalization indicator. For gravity field: 0 coefficients are unnormalized 1 coefficients are normalized 2 other. Reference Longitude 7 91 ASCII_Real 23 deg The reference longitude for the spherical harmonic expansion; normally 0. Reference Latitude 8 115 ASCII_Real 23 deg The reference latitude for the spherical harmonic expansion; normally 0. MGS Spherical Harmonic ASCII GMM2B Model Coefficients Table 1997-10-13 - 2000-02-29 244 404796 PDS DSV 1 The model was constructed from 955,115 observations, summarized in the table below. MGS data are limited to tracking from the Aerobraking Hiatus and Science Phasing Orbit (SPO) subphases of the Orbit Insertion phase of the mission and to February 1999 to February 2000 after the orbit was circularized. Time Periods Total Arcs Observations ----------------------- ---- ------------ Hiatus 2 24119 SPO-1 8 31001 SPO-2 16 157972 Feb-Mar 1999 9 76813 Apr 1999 - Feb 2000 47 665210 ----------------------- ---- ------------ Total 955115 3318 Carriage-Return Line-Feed Comma 6 0 Coefficient Degree 1 ASCII_Integer 5 %5d The degree index m of the C and S coefficients in this record. Coefficient Order 2 ASCII_Integer 5 %5d The order index n of the C and S coefficients in this record. C 3 ASCII_Real 23 %23.16e The coefficient Cmn for this spherical harmonic model. S 4 ASCII_Real 23 %23.16e The coefficient Smn for this spherical harmonic model. C Uncertainty 5 ASCII_Real 23 %23.16e The uncertainty in the coefficient Cmn for this spherical harmonic model. S Uncertainty 6 ASCII_Real 23 %23.16e The uncertainty in the coefficient Smn for this spherical harmonic model.