Monitoring soil wetness variation by a multi-temporal passive microwave technique

Microwave remote sensing offers emerging capabilities to monitor global hydrological processes. In particular, in the last years the potential in soil moisture retrieval has been largely demonstrated. Recently, an innovative Soil Wetness Variation Index (SWVI) has been proposed, using data acquired by the microwave radiometer AMSU1 which flies aboard NOAA2 satellites. SWVI is based on a general approach for multi-temporal satellite data analysis (RST-Robust Satellite Techniques) which, by means of a change detection technique applied over long-term multi-temporal satellite records, is able to identify anomalous values of the observed signal. Such an approach has already demonstrated, in several studies carried out on extreme flooding events which occurred in Europe in the past few years, its capability in reducing spurious effects generated by natural/observational noise. In this work, preliminary results obtained applying this approach to the flooding event which affected some European countries (luring the summer 2002, are presented. Preliminary outcomes seem to confirm the efficiency of the proposed indicator in monitoring soil wetness variations in the space-time domain without need auxiliary or ancillary information.