Filtered GRACE/GRACE-FO spherical harmonic coefficients of ITSG-Grace2018/ITSG-Grace_operational Level-2 GSM products representing an estimate of Earth's gravity field variations during the specified timespan. The spherical harmonic coefficients are filtered with VDK3 filter (anisotropic filter taking the actual error covariance information of the underlying GSM coefficients into account, see Horvath et al. (2018)). The filtered spherical harmonic coefficients are accompanied by their variance-covariance matrices which are gained via variance propagation from the variance-covariance matrices of the unfiltered coefficients.
This data set is basis of Boergens and Kvas (2021) and have been used in Boergens et al. (2021) to produce regional time series and their uncertainties, which can be reproduced with the code provided by Boergens (2021).