Improvements in GRACE-FO Accelerometer Modeling and Calibrations

Optimal gravity field recovery with GRACE/GRACE-FO requires the incorporation of high quality accelerometer data to account for the dynamic effects of non-gravitational forces. For GRACE-FO, a wide array of suboptimal features in the accelerometer data complicate the gravity retrieval process and necessitate calibrations for optimal mass change recovery. In particular, after an accelerometer mode switch approximately a month into the mission, systematic common mode errors on all six axes of the GRACE-D (GF2) accelerometer emerged; necessitating the use of a full accelerometer transplant from GRACE-C (GF1). A brief description of the features present in each satellite's accelerometer data and the calibrations necessary to mitigate them will be presented. Specifically, a focus on the calibration procedures which incorporate information recovered from the GF2 accelerometers will be compared to previous calibration procedures, in the context of gravity field recovery. Finally, avenues for future analysis and calibration updates will be discussed.