PIs: Roland Pail (TUM), Frank Flechtner (TUB)

Short description

In continuation of the first phase, IP5 will work towards the completion of the optimized stochastic modeling for GRACE and GRACE-FO gravity field adjustment. This includes three main tasks: (1) the extension of the stochastic instrument error models of the first phase including analyses of accelerometer data for longer time periods and of other key GRACE and GRACE-FO instrument data like GNSS, ranges and range accelerations; (2) the optimization of the combination of the different observations, where also the accelerometer data should be treated as observations in order to take into account the respective stochastic models in a more direct way; (3) the inclusion of tidal and temporally changing non-tidal background model error variance-covariance matrices in the adjustment process.

Research Objectives

1. Complete stochastic error characteristics (all data types and complete mission period)
2. Utilize optimal instrument data processing
3. Complete treatment of BM errors (modeling of non-tidal TV correlations) 
4. Develop the baseline strategy for reprocessing GRACE/-FO (to be implemented in SDS)

Innovations

• Stochastic models for the complete GRACE/-FO observation system
• Gravity models based on accelerometer data as observations
• Inclusion of time-variable background model error variance-covariance matrices for stochastic modeling