Contribution of small-scale correlated fluctuations of the microstructural properties of a spatially extended geophysical target under the assessment of radar backscatter

The study of the collective effects of radar scattering from an aggregation of discrete scatterers randomly distributed in a space is important for a better understanding of the origin of the backscatter from spatially extended geophysical targets (SEGT). We consider the microstructural irregularities of SEGT as the essential factor that affects radar backscatter. To evaluate their contribution, this study uses the “slice” approach: particles close to the front of an incident radar wave are considered to reflect incident electromagnetic waves coherently. The radar equation for a SEGT is derived. The equation includes contributions to the total backscatter from correlated small-scale fluctuations in the slice´s reflectivity. The correlation contribution changes in accordance with an idea proposed earlier by Smith (1964) based on physical consideration. The slice approach applied allows parameterizing the features of the SEGT´s inhomogeneities.