Small scale ground-based active microwave measurements over forest canopies

An attempt to contribute to give more insight in the scattering from forest canopies has been made recently by conducting an experimental project, named ERABLE, consisting in microwave measurements at a small scale. Two main applications are concerned, remote sensing of the Earth and radiomobile communications. The double objective of ERABLE was (i) measuring at a small scale forest backscattering coefficients and vegetation induced attenuation and (ii) validating scattering models. Two campaigns have been conducted in june 1996 and march 1997 over two forest sites, by means of a truck-mounted instrument operating at 2.2 GHz and 5.8 GHz, in a monostatic (scattering) and bistatic (attenuation) configuration and with HH, VV, VH and HV polarization diversity. This paper is devoted to a description of the experimental part of the project - the experimental setup and the attenuation measurement results-. Polarization, frequency, test sites diversity measurements and seasonal effects are investigated and extensively reported.