Ice classification in the Southern Ocean using ERS-1 scatterometer data

A simple method for classifying Southern Ocean sea ice from enhanced resolution ERS-1 scatterometer images is presented. The enhanced resolution images are created with the Scatterometer Image Reconstruction (SIR) algorithm. This algorithm uses a dense, irregular sample grid created with multiple, overlapping passes of the ERS-1 scatterometer to achieve resolutions better than the nominal 50 km ERS-1 resolution. Because the scatterometer provides measurements over a range of incidence angles, the incidence angle dependence of the observed σ° can be used as part of the classification algorithm along with the incidence angle normalized σ° improving the accuracy of the classification. In this study, a third parameter the standard deviation of a measure of the anisotropy, is used to further help delineate sea ice types