Accelerometer Parameterization and the Quality of Gravity Recovery and Climate Experiment Solutions

Abstract

In preparation for the Center for Space Research Release 6 of Gravity Recovery and Climate Experiment (GRACE) data, 32 accelerometer parameterization schemes are analyzed, which combine skew-symmetric, symmetric, and full-scale matrices with four different bias parameterizations inspired on those used on Release 5. After three selection stages, it has been determined that the daily full-scale matrix parameterization combined with the daily bias and linear drift improved the quality of the degree 60 GRACE spherical harmonic solutions by reducing the amplitude of north–south elongated artifacts by nearly 1 mm geoid height in some months. The improvements are largest during the period of 2002–2005 and after 2011. From 2007 to 2010, this parameterization scheme slightly degrades the GRACE solutions (limited under 0.1 mm geoid height increase in the intensities of north–south artifacts), but it has been demonstrated that this effect is limited to small areas and is barely visually noticeable. As a result of the proposed parameterization scheme, throughout the complete GRACE data period, the discrepancy of the coefficient relative to satellite laser ranging data has been reduced by a factor of 2.