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GLGM-3: A Degree-ISO Lunar Gravity Model from the Historical Tracking Data of NASA Moon OrbitersIn preparation for the radio science experiment of the Lunar Reconnaissance Orbiter (LRO) mission, we analyzed the available radio tracking data of previous NASA lunar orbiters. Our goal was to use these historical observations in combination with the new low-altitude data to be obtained by LRO. We performed Precision Orbit Determination on trajectory arcs from Lunar Orbiter 1 in 1966 to Lunar Prospector in 1998, using the GEODYN II program developed at NASA Goddard Space Flight Center. We then created a set of normal equations and solved for the coefficients of a spherical harmonics expansion of the lunar gravity potential up to degree and order 150. The GLGM-3 solution obtained with a global Kaula constraint (2.5 x 10(exp -4)/sq l) shows good agreement with model LP150Q from the Jet Propulsion Laboratory, especially over the nearside. The levels of data fit with both gravity models are very similar (Doppler RMS of approx.0.2 and approx. 1-2 mm/s in the nominal and extended phases, respectiVely). Orbit overlaps and uncertainties estimated from the covariance matrix also agree well. GLGM-3 shows better correlation with lunar topography and admittance over the nearside at high degrees of expansion (l > 100), particularly near the poles. We also present three companion solutions, obtained with the same data set but using alternate inversion strategies that modify the power law constraint and expectation of the individual spherical harmonics coefficients. We give a detailed discussion of the performance of this family of gravity field solutions in terms of observation fit, orbit quality, and geophysical consistency.
Document ID
20110013388
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Mazarico, E.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Lemoine, F. G.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Han, Shin-Chan
(Maryland Univ. Baltimore County Baltimore, MD, United States)
Smith, D. E.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Date Acquired
August 25, 2013
Publication Date
May 11, 2010
Publication Information
Publication: Journal of Geophysical Research
Volume: 115
Issue: E05001
Subject Category
Geophysics
Report/Patent Number
GSFC.JA.4511.2011
Distribution Limits
Public
Copyright
Other

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