GEOCON: Geodetic System Ties Using a CubeSat Constellation

Abstract

The accuracy of the Terrestrial Reference Frame (TRF), the foundation for geolocating all Earth Observations, is currently limited by systematic errors in tying together the contributions from the different geodetic techniques. Site ties using local surveys are currently limited by uncertainties in the relative position of the physical survey points and the typically inaccessible measurement reference points of the instruments. We are investigating the development of a new measurement concept using one or more space-based reference points (satellites) to significantly reduce the errors in the site ties between co-located geodetic ground stations. The proposed concept uses a novel idea of upconverting the Global Navigation Satellite System (GNSS) signal received at the satellite and transponding it to a Very Long Baseline Interferometry (VLBI) antenna ground station. This approach does not require the satellite to be in view of more than one VLBI station at a time, allowing the use of Low Earth Orbits.