RA-2 ENVISAT ocean retracking: the Southampton Oceanography Centre retracker scheme

Abstract

Present paper summarizes the capabilities of the ocean retracking model developed at the Southampton Oceanography Centre to retrieve geophysical parameters (mainly, significant wave height, backscatter power and range), using the RA-2 Envisat 18-Hz averaged waveforms. This model is based on the use of the Maximum Likelihood Estimation. One of the most important characteristics of the model is that non-linear parameters can be added, in order to derive more information from the ocean waveforms. First results show that the linear model is able to retrieve accurate geophysical parameters from RA2, but the use of the non-linear model has to be considered with care. This work is part of the RAIES project, for the exploitation of the Envisat radar altimeter individual echoes and S-band data for ocean, coastal zone, land and ice/sea-ice altimetry.