Astronomy and Astrophysics Orbit Determination for next Generation Space Clocks

In this paper, we study the requirements on orbit determination compatible with operation of next generation space clocks at their expected uncertainty. Using the ACES (Atomic Clock Ensemble in Space) mission as an example, we develop a relativistic model for time and frequency transfer to investigate the effects of orbit determination errors. We show that, for the considered orbit error models, the required uncertainty goal can be reached with relatively modest constraints on the orbit determination of the space clock, significantly less stringent than expected from ”naive” estimates. Our results are generic to all space clocks and represent a significant step towards the generalized use of next generation space clocks in fundamental physics, geodesy, and time/frequency metrology.