Local gravity from Lunar Prospector tracking data: Results for Mare Serenitatis

Abstract

High-resolution gravity anomalies on the surface of the Moon are determined from Lunar Prospector tracking data residuals. By means of a benchmark test the recovery method is validated with respect to the orbit determination and gravity field recovery strategy. Tracking data for the entire extended mission of Lunar Prospector, during which the satellite flew at an average altitude of 30 km above the lunar surface, have been completely and independently processed and orbits have been determined. Using tracking data residuals from these precise orbits, adjustments to the a priori gravity field model have been created for Mare Serenitatis. The results for Mare Serenitatis with the local recovery are comparable to global recovery results, yet faster and more efficient with a possibility to increase the resolution.

High‐resolution local gravity model of the south pole of the Moon from GRAIL extended mission data

“…Examples include analysis for Venus [ Barriot and Balmino , ], Mars [ Beuthe et al , ], and Jupiter's moon Ganymede [ Anderson et al , ; Palguta et al , ], without even mentioning the many applications to Earth‐orbiting satellites. Prior to the SELENE and GRAIL missions the tracking data distribution for the Moon was extremely asymmetrical with no farside data available, and thus, the Moon was especially suitable for the application of local methods, mostly using Lunar Prospector data: Sugano and Heki [] and Goossens et al [] estimated anomalies while Han [] and Han et al [] used localized spherical harmonic functions to model the nearside gravity field. These same functions were used by Goossens et al [] to estimate the gravity field over the South Pole‐Aitken basin on the farside of the Moon using SELENE data.…”

Local lunar gravity field analysis over the South Pole‐Aitken basin from SELENE farside tracking data

“…While processing the tracking data with GLGM‐2, we fixed some of the Keplerian orbit elements in order to ensure convergence of the short‐arc orbit determination problem. Fixed parameters were the same as those of Goossens et al [2005b]: the eccentricity, ascending node, and argument of pericenter. We also noted that the range data are not as sensitive to local gravity variations as the Doppler data, since including the range data distorted the solutions.…”

“…However, it was also realized that the full signal in the tracking data could not be accounted for even with these large expansions, as significant signatures were reported to be seen in the data residuals [ Konopliv et al , 2001]. This has lead to several recent analyses using local representations of the gravity field over the nearside of the Moon: Sugano and Heki [2004a, 2004b] used line‐of‐sight accelerations to estimate mass anomalies on the nearside of the Moon, while Goossens et al [2005a, 2005b] used Doppler data residuals directly to estimate gravity anomalies on the lunar surface. Again using line‐of‐sight accelerations, Han [2008] employed localized basis functions to estimate regional gravity fields on the nearside of the Moon for four locations, up to a resolution in spherical harmonics comparable to degree and order 200, and recently Han et al [2011] updated this analysis to include the whole of the nearside at the same resolution.…”

Overview of Differential VLBI Observations of Lunar Orbiters in SELENE (Kaguya) for Precise Orbit Determination and Lunar Gravity Field Study

“…We performed test observations of the Earth orbiters Geotail and Double Star and the Lunar orbiter Smart-1 with the Shanghai, Urumqi, Hobart and VERA stations in 2004, 2005 in order to check that all the required equipment worked as expected ). There were no serious problems with operating the VLBI systems during the test observations, and the observational accuracy using actual data was estimated.…”