Towards Millimeter-Level Accuracy in GNSS-Based Space Geodesy: A Review of Error Budget for GNSS Precise Point Positioning

Abstract The aim of the new generation Global Geodetic Observing System is a millimeter-level accuracy in positioning, with crucial role to be played by Navigation Satellites Systems (GNSS) Precise Point Positioning (PPP) mode. This course because GNSS constellations and receivers provide an efficient stand-alone technique homogeneous performance over large areas (positions, navigation meteorology) when used conjunction PPP mode, also ever-increasing data flow different satellite line-of-sights. requirement accuracies reaching millimeter or sub-millimeter implies knowledge at this level each line GNSS-PPP error budget, including, but not restricted to: clock biases, troposphere ionosphere delays, multipath ground deformations. In review study, we consider millimeter-/submillimeter possible mitigations improvements frame existing global constellations: GPS, Galileo, GLONASS BDS, view augmented and/or Low Earth Orbit constellations, which will available near future. We pay special attention systematic biases that can/could exist between constellations.