urn:nasa:pds:mgs-rss:data-sha:ggm1041c 1.0 1.22.0.0 Product_Observational 2025 MGS RSS This file contains coefficients and related data for the spherical harmonic model MGM1041C of the Mars gravity field. Input data are from radio tracking of the Mars Global Surveyor spacecraft. The MGM1025 gravity model is an update to the GMM-2B gravity model. The data cover 1997-10-13T00:00:00Z to 2002-05-27T23:59:59Z. Frank Lemoine 1 Goddard Space Flight Center https://ror.org/0171mag52 David Smith 2 Goddard Space Flight Center https://ror.org/0171mag52 2025-02-11 1.0 This product, GGM1041C.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 2002-05-27T23:59:59Z 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 urn:nasa:pds:mgs-rss:data-maps:ggm1041a::1.0 data_to_derived_product urn:nasa:pds:mgs-rss:data-maps:ggm1041b::1.0 data_to_derived_product urn:nasa:pds:mgs-rss:data-maps:ggm1041c::1.0 data_to_derived_product 10.1023/A:1013939327465 P.K.S., Abalakin, V.K., Bursa, M. et al. Report of the IAU/IAG Working Group on Cartographic Coordinates and Rotational Elements of the Planets and Satellites: 2000. Celestial Mechanics and Dynamical Astronomy 82, 83-111 (2002). The coordinate system for the new model is IAU 2000 defined by the Mars Cartography Working Group. It includes updates to the orientation of the Mars Pole and rotation rate from a joint Pathfinder/Viking solution, and a re-determination of the location of the prime meridian (with respect to the crater Airy-0) from Mars Global Surveyor MOC and MOLA data. Pole right ascension (alpha) and declination (delta), prime meridian (Wo), and rotation rate (Wodot) in IAU 2000 are: alpha = 317.68143 deg -0.1061 deg/century delta = 52.88650 deg -0.0609 deg/century Wo = 176.630 deg Wdot = 350.89198266 deg/day Gravitational constants obtained from the solution are: GM (Mars) = 4.282837024529127 E+13 m**3/s**2 sigma = 0.617 E+05 m**3/s**2 GM (Phobos) = 0.68012569 E+06 m**3/s**2 sigma = 0.842 E+04 m**3/s**2 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:GGM1041C.SHA:GGM1041C.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. GGM1041C.SHA 2003-11-25T16:38:36 510570 93ff7c48ebeed0745b83d90a6847dfb7 MGS Spherical Harmonic ASCII MGM1041C Model Header 1997-10-13 - 2002-05-27 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 MGM1041C Model Coefficients Table 1997-10-13 - 2002-05-27 244 510326 PDS DSV 1 The model was constructed from 2,568,683 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 May 2002 after the orbit was circularized. Time Periods Total Arcs Observations ------------------------ ---- ------------ Hiatus 2 24119 SPO-1 8 31014 SPO-2 17 144253 Feb-Mar 1999 10 86069 2 Apr 1999 - 22 May 2002 167 2186533 Doppler + Crossovers 5 96875 ------------------------ ---- ------------ Total 2568863 4183 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.