Recognition of sea ice zones using ERS-1 scatterometer data

The ERS-1 scatterometer was designed as an instrument dedicated to making wind measurements over the sea. Since backscattering over sea ice is often quite similar to that over the open ocean, it is not possible to screen out ice zones by simple tests of individual sigma naught triplets. This paper demonstrates the feasibility of detecting ice using anisotropy of the scatterometer sigma naught triplets. This is of interest as a possible method for improving ERS-1 Fast Delivery Wind quality in the near future. The method developed is based on the analysis of the responses (sigma naught) of the fore and aft beams of the ERS-1 scatterometer. If the authors assume that a flat ice surface has an isotropic response fore and aft measurements should be identical. To investigate this, the authors used an anisotropy factor, defined as the normalised difference between the fore and aft beam sigma naughts.<
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