Characterization of the electromagnetic response of maize crops with polarimetric backscatter profiles

An exhaustive analysis of the electromagnetic response from a maize sample, measured in laboratory conditions, is presented. Fully polarimetric wide-band radar data have been collected in order to compute backscatter profiles (i.e. 1D images) as a function of height. First results consist on backscatter images expressed in Pauli and linear basis. These plots demonstrate that the extinction coefficient is higher for vertical polarization than for horizontal polarization due to the predominant vertical orientations of the components of the corn plants (mainly the stems). In addition, the crosspolar backscattered power decreases importantly as the frequency increases, and it is always lower than the copolar returns, again as a result of the oriented morphology, which produces a very low depolarization of the signal. On the other hand, the second kind of results is based on the polarimetric target decomposition proposed by Cloude and Pottier. Height profiles of alpha, entropy and anisotropy have been calculated. These parameters have been carefully analyzed in order to extract information to be used in the application of parameters inversion algorithms