Stochastic models for GRACE/GRACE-FO accelerometers and inter-satellite ranging instruments

This data publication represents the main outcomes of WP4.100 of Individual Project IP4 and of the Deliverable D4.1 of the research unit NEROGRAV summarizing the analyses of the GRACE and GRACE-FO accelerometer (ACC) and satellite-to-satellite tracking data (Microwave instrument (MWI) or Laser Ranging Interferometer (LRI)) in order to derive a characterization of the instrument performance and a stochastic model. A detailed description and discussion focusing on the GRACE data is given in Murböck et al. (submitted to Remote Sensing). This first version of the combined ACC+MWI/LRI noise models is provided with the ASCII-file NEROGRAV_Dataset_GRACE_GRACE-FO_ACC-MWI-LRI_StochasticModel_V01.dat containing header information (17 lines) and the square root power spectral densities (PSDs), i.e. the amplitude spectral densities (ASDs) for the combined accelerometer and ranging observations in terms of range-rates (cf. Fig. 1). It is given for 21600 frequencies from 1/86400 Hz up to 0.25 Hz. Above 0.1 Hz (Nyquist frequency of the 5 s sampled MWI data) the columns for the ACC+MWI models are zero. The five columns consist of the frequency in Hz (col. 1), the combined ACC+MWI models for GRACE 2007 (col. 2), GRACE 2014 (col. 3), GRACE-FO 2019 (col. 4) and the combined GRACE-FO 2019 ACC+LRI model (col. 5) in m/s/√Hz.