Microwave remote sensing of hydrological parameters on the NOPEX area

A research project aimed at evaluating the microwave remote sensing methods for producing some basic parameters of land surfaces which in ̄uence the hydrological cycle, on a regular basis, has been conducted within the framework of the European Northern Hemisphere Climate Processes Land-surface Experiment (NOPEX) and Forest-Dynamic and Monitoring (ForestDynamo) experiments. In this paper, the sensitivity of the backscattering coef®cient at C-and L-bands to soil moisture, surface roughness and herbaceous and arboreous biomass has been investigated by analysing experimental data collected with Synthetic Aperture Radar in Northern Europe by the airborne EMISAR during the European Multisensor Airborne Campaign (EMAC), organised by the European Space Agency and in Italy during the Multisensor Airborne Campaign (MAC-91) and the Shuttle Imaging Radar (SIR-C) experiment, both organised by NASA with the cooperation of the Italian Space Agency. An analysis of SSM/I (Special Sensor Microwave Imager) radiometric satellite images, carried out over several Scandinavian regions, which has shown sensitivity to seasonal changes of vegetation and snow cover of microwave emission, is also reported. # 1999 Elsevier Science B.V. All rights reserved.