Numerical-Analytical Model of Reflection Coefficient for Rough Soil Surface in Wide Frequency Range

In this work, a numerical-analytical model of reflection coefficient for rough soil surface in wide frequency band was proposed. The field of reflected wave from the rough soil surface is presented as the sum of secondary fields from an infinite set of elementary horizontal scattering plates (with a given average size). The field from each elementary scattering plate is represented as an average field from the result of stochastic interference of an infinite set of coherent elementary sources of secondary waves. The vertical position of the elementary sources is determined by the stochastic height of the soil surface within elementary plate. The case of the coherent component and the total value (coherent+diffuse components) of reflection coefficient is considered. On the basis of the created model of reflection coefficient, a broadband method for simultaneously retrieved the root-mean-square deviation of the stochastic soil surface heights and volumetric soil moisture was developed. The results have a wide application value both for single-frequency and multi-frequency radar and radiometric methods of soil moisture measuring.