Potentials of X-band active and passive microwave sensors in monitoring vegetation biomass

A long term analysis of vegetation emission and scattering characteristics was carried out by using microwave airborne and ground-based radiometric systems by the Microwave Remote Sensing Group of IFAC-CNR. A comparison with active sensors at the same frequency became promising after the launch of Cosmo-Skymed and Terra-SARX satellites. In this paper the potentials of both emissivity and backscatter at X-band for the monitoring of plant parameters are investigated and the interrelations between these two quantities are discussed. Remote sensing data collected in agricultural surfaces and for different crop types in Italy have been analyzed and compared with vegetation parameters (mainly plant water content and leaf area index) measured on ground. A discrete element radiative transfer model tuned for both active and passive cases was used to perform a sensitivity analysis. A direct comparison of measure emissivity and backscattering is carried out.