The Shipborne Kinematic Positioning Accuracy of Using GPS Precise Point Positioning (PPP) Technique: A Case Study in Shipborne Gravity Measurement around Taiwan

Abstract

From 2004 to present, the GPS phase observation data have been collected in the shipborne gravity measurement around Taiwan, which are used to determine sea surface heights (SSHs) that are equivalent to satellite altimeter-derived SSHs. The ship-based SSHs are corrected for ocean tide and body tide effects, but no tropospheric and ionospheric corrections are needed because they are already applied in GPS positioning. In coastal areas, satellite altimetry is often affected by bad radar waveforms, but ship-based altimetry is not, which makes ship-base altimetry can obtain more accurate SSH than satellite altimetry. In this paper, precise point positioning (PPP) technique is used to determine the ellipsoid heights of ship, and the positioning accuracies are assessed by comparing with DGPS and analyzing the crossover difference of SSHs. This paper will also present the limitation and the prospect of ship-based altimetry.