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

• Published in: Geophysical Research Letters
• Main Authors: Goossens, Sander, Sabaka, Terence J, Nicholas, Joseph B, Lemoine, Frank G, Rowlands, David D, Mazarico, Erwan, Neumann, Gregory A, Smith, David E, Zuber, Maria T
• Format: Text
• Language: English
• Published: John Wiley & Sons, Ltd 2014
• Subjects: Research Letters; South Pole; South pole
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4459178/; https://doi.org/10.1002/2014GL060178

We estimated a high-resolution local gravity field model over the south pole of the Moon using data from the Gravity Recovery and Interior Laboratory's extended mission. Our solution consists of adjustments with respect to a global model expressed in spherical harmonics. The adjustments are expressed as gridded gravity anomalies with a resolution of 1/6° by 1/6° (equivalent to that of a degree and order 1080 model in spherical harmonics), covering a cap over the south pole with a radius of 40°. The gravity anomalies have been estimated from a short-arc analysis using only Ka-band range-rate (KBRR) data over the area of interest. We apply a neighbor-smoothing constraint to our solution. Our local model removes striping present in the global model; it reduces the misfit to the KBRR data and improves correlations with topography to higher degrees than current global models.