SENSITIVITY OF MICROWAVE MEASUREMENTS TO VEGETATION BIOMASS AND SOIL-MOISTURE CONTENT - A CASE-STUDY

A comparative evaluation of the potential of active and passive microwave sensors in estimating vegetation biomass and soil moisture content is carried out. For this purpose, experimental data collected on an agricultural area, by airborne scatterometers and radiometers, during the AGRISCATT and AGRIRAD 1988 Campaigns, have been used. The results show that both microwave backscattering and emission are sensitive to vegetation biomass over a wide frequency range. Multifrequency observations seem to offer good probabilities for separating wide leaf from small leaf herbaceous crops, and for detecting different growth stages. Low frequency data (L band) at a steep incidence angle (10-degrees) confirm that both the backscattering coefficient and the normalized temperature are correlated and sensitive to soil moisture content.