Unification of a Global Height System at the Centimeter-Level Using Precise Clock Frequency Signal Links

The International Association of Geodesy (IAG) aims to establish the Height Reference System (IHRS) as one its primary scientific objectives. Central realization IHRS is global vertical datum unification, which requires connection existing local height reference systems (VHS) robustly and consistently. However, conventional methods are not suitable for estimating offsets between two distant systems. In this paper, we propose a framework connecting VHSs using ultraprecise clock frequency signal links satellites ground stations, referred satellite transmission (SFST) approach. SFST approach allows direct determination geopotential differences stations without any location restrictions VHSs. simulation results show that China US can be unified with an accuracy several centimeters, provided stability atomic clocks used on-board at on-ground locations reaches 4.8×10−17τ−1/2 averaging time τ (in seconds). We conclude shows promise achieving centimeter-level in unifying represents new paradigm IHRS.