Context. The upcoming Chinese Tianwen-4 mission, featuring both primary and secondary satellites, promises to significantly enhance our understanding of Jupiter’s gravity field. We provide here a comprehensive evaluation of its contribution to modeling of Jupiter’s gravity field. Aims. This study investigates the potential contribution of the Tianwen-4 mission to the estimation of Jupiter’s gravity field and the tidal effects knm associated with the Galilean moons by incorporating spacecraft-to-spacecraft tracking (SST) alongside traditional two-way (2W) observations. Methods. We analyze various observational factors, such as orbital altitudes, noise levels, data durations, and tidal responses, to evaluate their impact on gravity field estimation accuracy. Results. Our analysis demonstrates that the combined 2W and SST mode enhances the precision of gravity field estimates by up to an order of magnitude, reducing formal errors, and improving spatial resolution compared to the 2W mode alone, even when using shorter arcs data. Furthermore, the combined mode yields a superior performance in the estimation of Love numbers, with lower orbital altitudes and longer data collection periods further improving accuracy, despite introducing operational challenges. Conclusions. The enhanced sensitivity and accuracy provided by the SST configuration offer valuable insights into Jupiter’s internal structure and dynamics, thereby guiding the design of future missions aimed at maximizing scientific returns.
Afzal et al. (Wed,) studied this question.