Interpretation of radar measurements from rough soil surface with a permittivity profile

The IEM surface scattering model was applied to interpret sets of multifrequency, multipolarization radar measurements acquired from rough soil surfaces with measured permittivity profiles. The wetness was induced by irrigation and the profile was generated by evaporation. It is known that surface roughness parameters are difficult to estimate and are dependent on the measurement system resolution and record length. Hence, roughness parameters for a soil surface were estimated using the IEM surface scattering model applied to a data set at C- or L-band when the soil condition is wet. Then, the same surface parameters were used at other frequencies and moisture conditions. The measured permittivity profile is used to compute the effective reflection coefficient for the entire soil medium at normal incidence on the air-soil boundary from which an effective permittivity is derived for the soil medium and used for scattering calculation. For soil with a dry upper surface and an increasing permittivity value with depth an additional air-soil transition in permittivity is needed in estimating backscattering