Comparison of the reduced dynamical orbit parametrization and precise non-conservative orbit force modeling for DORIS satellites

The focus of the studies is the analysis of the comparison between two different approaches for LEO satellite orbit estimation employing DORIS measurements. The first one is the reduced-dynamical model, based on the orbit modeling by using the empirical and the pseudo-stochastic parameters. The second approach includes the attitude models and the CNES-developed satellite macromodels, with modeling of non-conservative acceleration, i.e., Sun radiation pressure, Earth radiation pressure and atmospheric drag. Both approaches are used at analysis centers providing DORIS solutions. The reduced-dynamical modeling is currently used by the GOP analysis center, which achieves similar accuracy of the free-network solutions as the other centers utilizing a precise non-conservative force modeling. The GOP works with a modified version of the Bernese GPS Software that has not included the non-conservative modeling. This limitation is now overcome by the new scientific modification of the software, which opens the unique possibility to compare both approaches by using the same software platform. We compare external and internal precision of the estimated orbits. We also analyze the individual satellite free-network DORIS solutions and time-series of derived parameters, i.e., station coordinates, TRF scale, the geocenter variations and the Earth rotation parameters. The studies highlight the main differences in the results that should answer the question whether the modeling of non-conservative forces including the CNES box-wing satellite models actually brings a significant improvement to the DORIS solutions.