Wet Tropospheric Delay Correction of Wide-Swath Altimeter based on the Mixing of Nadir Radiometer and Gridded Data Product

Abstract

Wet tropospheric delay (WPD) is a critical error source of altimeters. The current radiometers have been able to obtain ideal along-track correction values. However, the small-scale spatial variability of the water vapor is a huge challenge for correcting the wide-swath altimeter. Even though the total residual error can meet the error budget by a two-beam radiometer, the correction effect at the edge of the swath is still difficult to control. This paper proposes a WPD correction method based on mixing nadir radiometer and gridded data product by spatial correlation function. The corrected residual root mean square error (RMSE) and cross-track distribution characteristics of different methods are compared through the simulation data. The results show that the total RMSE of the mixed method is similar to the two-beam method but has better cross-track stability.