SLR sliding window solutions with daily sampling for replacing GRACE/GRACE-FO C20 and C30

The recovery of Earth’s time variable gravity field from satellite data relied on Satellite Laser Ranging (SLR) before missions like the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (FO). Currently, the monthly gravity solutions from GRACE/GRACE-FO provide amazing information about the temporal variations of gravity field.  However, coefficients C₂₀ and C₃₀ derived from GRACE/GRACE-FO are unreliable. The coefficients, on the other hand, can be reasonably well determined using SLR data and can be used to replace the unreliable values from GRACE/GRACE-FO. In the future, GRACE-FO will provide 28-day sliding widow gravity solutions with weekly sampling. The corresponding SLR solutions should be also provided. Based on this motivation, we study the SLR 30-day sliding window solutions with daily sampling. The new SLR products can be used to replace unreliable coefficients C₂₀ and C₃₀ of both GRACE-FO monthly and sliding window products. This study presents the strategies of gravity recovery from SLR data and discusses the results.