These operationally published products complement the time series of the already established ACs and allow for a continuous and independent assessment of mass changes in Earth’s system. The regularly updated LUH-GRACE-FO-2020 time series of monthly gravity field solutions can be found on the website of the International Centre for Global Earth Models (ICGEM) and in LUH’s research data repository. Presented results are based on 29 monthly gravity field solutions from June 2018 until December 2020. To our knowledge, the detailed origin of these spikes and their influence on the gravity field recovery quality were not addressed in any study so far and therefore deserve further attention in the future. Nevertheless, the power spectral density of GRACE-FO and GRACE post-fit residuals is dominated by similar spikes located at multiples of the orbital and daily frequencies. GRACE-FO post-fit residuals show less systematics, compared to GRACE. The overall amplitude of GRACE-FO post-fit residuals is about three times smaller, compared to GRACE. The carried out comparison of GRACE and GRACE-FO KBRR post-fit residuals highlights an improvement of the GRACE-FO K-band ranging system performance. While the spectral and spatial noise levels slightly differ, the signal content of the solutions is similar among all ACs. A comparison of the obtained solutions to the results of the GRACE-FO Science Data System (SDS) and Combination Service for Time-variable Gravity Fields (COST-G) ACs, reveals a competitive quality of our solutions. K-band range-rates (KBRR) and kinematic orbits are used as (pseudo)-observations. We use the in-house-developed MATLAB-based GRACE-SIGMA software to compute unconstrained solutions based on the generalized orbit determination of 3 h arcs. The purpose of this article is to give a detailed insight into the gravity field recovery processing strategy applied at LUH to compare the obtained gravity field results to the gravity field solutions of other established ACs and to compare the GRACE-FO performance to that of the preceding GRACE mission in terms of post-fit residuals. The Institute of Geodesy (IfE) at Leibniz University Hannover (LUH) is one of the most recent ACs. The successor mission GRACE Follow-On (GRACE-FO) was launched in May 2018 and proceeds observing Earth’s TVG. Monthly gravity field solutions as the main products of the GRACE mission, published by several analysis centers (ACs) from Europe, USA and China, became indispensable products for quantifying terrestrial water storage, ice sheet mass balance and sea level change. The unprecedented quality of gravity field solutions from GRACE sensor data improved the understanding of mass changes in Earth’s system considerably. Two weeks ago, NPR reported that spending on regular clothing and accessories has fallen 79, but retailers are reporting major spikes in searches for. During its science phase from 2002–2017, the low-low satellite-to-satellite tracking mission Gravity Field Recovery And Climate Experiment (GRACE) provided an insight into Earth’s time-variable gravity (TVG).
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