Numerical simulations on GENESIS' contribution to the determination of terrestrial reference frame (TRF) parameters

The ESA's GENESIS mission, scheduled for launch in 2028, collocates the four geodetic techniques (DORIS, GNSS, SLR and VLBI) on a single spacecraft, with accurate calibration of the platform and instruments, and a shared clock/frequency source for the active instruments. To assess the expected performance of this mission, we perform end-to-end simulation studies using the GINS/DYNAMO software developed at CNES. Our analysis examines how multi-technique GENESIS observations could contribute to the determination of the Terrestrial Reference Frame (TRF) and Earth rotation parameters, as well as to the detection of inter-technique biases. The simulations acccount for technique-specific error sources, dynamical modeling and instrument calibration uncertainties to assess realistic scenarios. We examine the use of the common orbit as a link between techniques to evaluate how multi-technique combined GENESIS-like solutions at the observation level affect the TRF parameters, in particular the origin and scale, and the inter-technique consistency within the combined TRF solutions.