TIDUS is a joint project between DGFI-TUM and FU Berlin within the DFG-funded Research Unit 2736 New Refined Observations of Climate Change from Spaceborne Gravity Missions (NEROGRAV) that aims to improve both accuracy and consistency of time-variable gravity field models and its derived products of mass transport and mass re-distribution. The central hypothesis of the RU is that "Only by concurrently improving and better understanding of sensor data, background models, and processing strategies of satellite gravimetry, the resolution, accuracy, and long-term consistency of mass transport series from satellite gravimetry can be significantly increased; and only in that case the potential of future technological sensor developments can be fully exploited".
Imperfect ocean tide models are considered among the most limiting factors in determining high-resolution temporal gravity fields. At the same time, only incomplete information about the uncertainties of current ocean tide models is available. In particular, the influence of uncertainties on satellite gravity products is not yet quantified. The TIDUS project is investigating the impact of errors in ocean tide models on global gravity field solutions. Therefore, realistic errors for relevant ocean tidal constituents in different geographical regions are assessed. A strong focus is placed on secondary ocean tide effects due to minor tides, atmospheric tides, and tidal loading. Moreover, strategies for achieving regional improvements of ocean tides in critical regions are developed.