Semi-empirical modeling of bare soil surfaces at millimeter-wave frequencies

The millimeter-wave backscatter response of bare soil surfaces was examined by conducting experimental measurements at high incidence angles using a 95-GHz instrumentation radar. It was found that the backscattering coefficients at high incidence angles exhibited a weaker dependence on the incidence angle when compared to the data collected in an earlier study at low incidence angles. On the other hand, it was found that the behavior of both the co-polarized ratio p and the cross-polarized ratio q of the backscattering coefficients conformed well with the conclusions drawn from the earlier study. A semi-empirical surface scattering model was developed to relate the backscattering coefficients to the soil´s surface properties over all incidence angles