Toward a Geodesy and Time Reference in Space (GETRIS): A Study of Apparent Satellite Clocks of a Future GNSS Satellite Constellation

Today, concepts within the Global Geodetic Observing System (GGOS) aim a Terrestrial Reference (TRS) with 1 mm accuracy and long-term stability of 0.1 mm/year. GETRIS (Geodesy Time In Space) is concept that aims to realize relativistic reference system based on satellites as an extension TRS. This helps another goal GGOS, namely, connection different satellite layers For valuable contribution GGOS’s goals, we would expect achieve precise determined orbits at level 1–3 clocks picosecond accuracy. The use increasingly links improve orbit determination (POD) necessary synchronize in satellite/station network. We analyze complementary high-precision optical dual one-way precision together L-band. previous studies, analyzed benefit for POD, achieving Medium Earth Orbit (MEO) well geosynchronous (GSO) accuracies low-millimeter level. this work, capabilities clock synchronization. compare two types estimation prediction. constellations combinations measurement links.