The Evanescent Field Transform for Estimating the Parameters of Homogeneous Random Fields with Mixed Spectral Distributions

Parametric modeling and estimation of complex valued homogeneous random fields with mixed spectral distributions is a fundamental problem in two-dimensional signal processing. The parametric model under consideration results from the two-dimensional Wold-type decomposition of the random field. The same model naturally arises as the physical model in problems of space-time adaptive processing of airborne radar. A computationally efficient algorithm for estimating the parameters of the field components is presented. Thus, efficient estimation of the parametric models that represent the interference components in the radar problem is possible. The algorithm is based on a non-linear operator that uniquely maps each evanescent component to a single exponential. The exponential's spatial frequency is a function of the spectral support parameters of the evanescent component. Hence, employing this operator, the problem of estimating the spectral support parameters of an evanescent field is rep..