EFFECT OF FOREST THINNING ON THE RADAR BACKSCATTERING COEFFICIENT AT L-BAND

This letter presents preliminary results of a study concerning the inf luence of forest thinning on the backscattering coefficient (sigma deg rees) at L-band by using data from the JPL-NASA campaign MAESTRO-1 and MacEurope on Les Landes forest, France. The backscattering coefficien t of thinned and unthinned stands were compared and interpreted with t he help of model simulations. It is shown that thinning significantly influences the backscattering coefficient of adult stands, particularl y at HV polarisation where sigma degrees was reduced by up to 4 dB. Mo reover, the density variation of the stand did not explain all this de crease in sigma degrees. Secondary structure modifications induced by the thinning are likely to have considerable influence on the backscat tering coefficient.