Comparing GRACE-FO Mascon Solutions Computed Using Range-Rate vs Range-Acceleration Data from K-Band Ranging (KBR) and Laser Ranging Interferometer (LRI)

The GRACE Follow-On (GRACE-FO) mission, launched on May 22, 2018, is continuing the unprecedented mass anomaly time-series started by the GRACE mission. The 18 year record of global mass change fields have become indispensable to track the movement of water in the Earth System and monitor changes in the ice sheets, glaciers, surface water, ground water, sea level, ocean currents etc.

The traditional GRACE and GRACE-FO mascon solutions produced at the Center for Space Research uses the range-rate measurement from the intersatellite K-band ranging (KBR) data. In this paper we present techniques for computing alternate mascon solutions using range-acceleration measurements from the K-band ranging system. We discuss the comparison in techniques used and the results produced using SST range-rate vs range-acceleration data. GRACE-FO carries a technology demonstration of Laser Ranging Interferometer (LRI) system which offers a 10x improvement in the ranging measurement system. We discuss the comparison of the technique, parameterization and the resulting mascon solution derived using range-acceleration data from the KBR and LRI system.