GPS Interferometric Reflectometry Measurements of SEA Levels with Two Tropospheric Correction Models: Assessment and Analysis

Abstract

Sea level is an important variable to study environmental change. GPS-IR has been proven to be an effective technique to estimate sea levels. As a main error source of the GPS-IR-derived sea levels, the tropospheric delay has rarely been studied. In this paper, using 10-day SNR observations recorded by a coastal GPS site SC02, we assessed the performances of two tropospheric models (i.e. the Bennett model and WN model) with different refraction assumptions. Our results show that the GPS-IR-derived sea levels have an RMSE of 16.9 cm compared with the tide gauge observations. Both models significantly reduced the error of estimated sea levels by ~30%, while the Bennett model performed slightly better than the WN model by ~5 mm. Moreover, the tropospheric height biases estimated by both models were proportional to the estimated height of the GPS receiver above the sea surface.