Aquarius Third Stokes Parameter Measurements: Initial Results

This letter reports a first look at the polarimetric (third Stokes parameter) channel on the Aquarius L-band radiometer that was launched in June of 2011 on the Aquarius/Satélite de Aplicaciones Cientificas (SAC)-D observatory. The primary purpose of the polarimetric channel is to provide an in situ measure of Faraday rotation which can be important for remote sensing at L-band, particularly in the case of sea surface salinity. However, it also provides an additional mode of observation and a chance to look for new features of the surface. Initial results show good agreement with expectations. In particular, the values of retrieved Faraday rotation agree with predicted values, and a nonzero signal is seen to occur over mixed scenes as predicted by theory.