SOIL-MOISTURE ASSESSMENT AT A BASIN-SCALE USING ACTIVE MICROWAVE REMOTE-SENSING - THE AGRISCATT-88 AIRBORNE CAMPAIGN ON THE ORGEVAL WATERSHED

In June and July 1988, the European Space Agency organized in five Eur opean countries the Agriscatt '88 campaign. For this campaign two airb orne scatterometers were used, including the French dual-frequency (C and X band) dual-polarization (HH and VV) forward-looking radar ERASME . For the French site, the Orgeval hydrological basin, one of the aims of the experiment was to develop a soil moisture retrieval algorithm from radar data. It is shown, from comparison with the ground-truth da ta, that the use of a multiconfiguration radar improves the capacity o f imaging radar for soil moisture mapping. In particular, an algorithm based on a vegetation absorption index and a soil moisture one is tes ted over wheat fields.