**NSSDCA ID:** PSPG-00857

**Availability:** Archived at NSSDC, accessible from elsewhere

**Time span:** 1966-08-10 to 1999-07-30

This description was generated automatically using input from the Planetary Data System.

The gravitational signature of the Moon was determined from velocity perturbations of the Lunar Prospector (LP) spacecraft as measured from the Doppler shift of the S-band radio tracking signal. LP was tracked by NASA's Deep Space Network (DSN) at Goldstone, California, Canberra, Australia, and Madrid, Spain. The tracking data were used to determine the LP orbit about the Moon, as well as the lunar gravity field [KONOPLIVETAL1998]. The LP data were combined with S-band tracking observations from Lunar Orbiters 1, 2, 3, 4, and 5 and from the Apollo 15 and 16 subsatellites [KONOPLIVETAL1993B] and from Clementine [LEMOINEETAL1997]. In advance of the LRO mission, the Lunar Prospector and other historical tracking data were re-analyzed and the GLGM-3 model was developed. The model is documented in a JGR paper [MAZARICOETAL2010]. In addition, the GLGM-3 model was extended to degree 200 using a Line-of-Sight (LOS) analysis technique [HANETAL2011] to produce the LPE200 model. Data ==== There are 2 data types for the gravity products found on this volume: tabular and array data. The files containing the spherical harmonic coefficients of the Moon's gravity field (GLGM3150, LPE200) are in tabular (ASCII) and array (BINARY) format, with each row in the table containing the degree index m, the order index n, the coefficients Cmn and Smn, and the uncertainties in Cmn and Smn. The binary array file is a little-endian, row ordered upper triangular matrix. Coordinate System ================= The coordinate system for the gravity data, and the coefficients in the GLGM3150 and LPE200 gravity fields is selenocentric, center of mass, longitude positive east. The location of the pole and the prime meridian are defined by the principal axes as given by the integrated lunar librations of DE421 [WILLIAMSETAL2008]. Processing ========== The GLGM3 gravity solution consists of 4,324,171 observations, of which 3,570,901 were contributed by LP. The data were divided into 1225 independent arcs based on considerations of data coverage and timing of maneuvers. The table below summarizes the number of observations and arcs from each spacecraft: Satellite Number Total Periapsis Apoapsis of Arcs Observ. (km) (km) Lunar Orbiter-1 70 48,575 50 1830 Lunar Orbiter-2 90 77,726 50 1870 Lunar Orbiter-3 73 62,264 50 1820/320 Lunar Orbiter-4 32 48,688 2700/75 6000/4000 Lunar Orbiter-5 70 42,916 100/170 1750/2000 Apollo-15 subsatellite 93 52,500 75 160 Apollo-16 subsatellite 46 42,579 30 190 Clementine 40 378,022 370 2960 LP (nominal) 184 2,198,751 90 110 LP (extended) 127 1,372,150 25 45 Total 1225 3,570,901 For each arc certain parameters were determined: for example, the spacecraft state (position and velocity), solar radiation pressure coefficients, Doppler biases for each station over the arc to account for frequency biases, and increments in velocity to account for spacecraft manuevers. The DE421 set of planetary and lunar ephemerides was used in the analyses. Average data fits and the final effective data weight for each set of the data in the solution are as follows: Satellite Avg. RMS of fit Eff. Data Wt. (cm/s) (cm/s) Lunar Orbiter 1 0.24 3.16 Lunar Orbiter 2 0.11 3.16 Lunar Orbiter 3 0.07 3.16 Lunar Orbiter 4 0.05 0.55 Lunar Orbiter 5 0.21 0.49 Apollo 15 subsatellite 0.12 0.95 Apollo 16 subsatelite 0.15 0.32 Clementine 0.31 1.34 Lunar Prospector (nom) 0.02 1.41 Lunar Prospector (ext) 0.25 3.78 Media/Format ============ This data set is stored online at the Planetary Data System (http://pds.nasa.gov/) and may be downloaded using a web browser or FTP software. A copy may be requested on physical media if downloading is not possible. The Planetary Data System maintains backup copies of this data set on various media.

These data are available on-line from the Planetary Data System (PDS) at:

http://pds-geosciences.wustl.edu/lunar/lp-l-rss-5-glgm3_gravity-v1/lp_1201/

- LP-L-RSS-5-GLGM3/GRAVITY-V1.0

- Planetary Science: Geology and Geophysics

Questions and comments about this data collection can be directed to: Dr. David R. Williams

Name | Role | Original Affiliation | |
---|---|---|---|

Dr. Erwan M Mazarico, Jr. | General Contact | NASA Goddard Space Flight Center | erwan.m.mazarico@nasa.gov |