Assessment of Retracked Envisat Altimetry Sea Surface Heights near Hainan Coastal Ocean

Abstract:

Four waveform retracking algorithms, Ocean1, Threshold, Offset center of gravity (OCOG), and Beta 5 parameter retracking algorithms, were used to retrack the Envisat waveforms over the Hainan coastal ocean and the accuracy of retracked sea surface heights (SSHs) were assessed. The results indicate that the accuracy of the SSHs can be improved by waveform retracking algorithms and the spatial resolution of the retracked SSHs is significantly improved. The accuracy of the Threshold 50% Algorithm is the highest and the Oceanl Algorithm also performs better than the other two. The Threshold 50% Algorithm is the most stable retracking method and more suitable for the Envisat waveform retracking over Hainan coastal ocean.

Key words:satellite altimetry; waveform retracking; coastal ocean; sea surface height; assessment indicators