Resolution Improvement of ERS Scatterometer Data Over Land by Wiener Filtering

Multiplicative Wiener deconvolution has been applied to ERS scatterometer measurements obtained over land with the aim of improving their spatial resolution. The ERS scatterometer was launched to provide high-accuracy radar backscattering measurements over the sea surface for the purpose of monitoring marine wind velocity. However, ERS scatterometer data soon inspired an increasing interest for land and sea ice monitoring. The main shortcoming of these applications has been the coarse resolution of the device. This varies between 25 km2 and 46 km2 before ground processing, which results in normalization down to ∼48 km2 so that all the measurements can be used jointly in the wind vector retrieval. Nevertheless, for the case of perdurable sea ice and land scenes, measurements with 25-km resolution before ground processing can be selected to form images. As will be shown here, this finer resolution can be recovered for these images by using a linear Wiener filter. This restoration technique was tested on a large scene from Russia. The improvement can be observed in the definition of the line of the river Obʹs basin.