Basic concepts of radar polarimetry and its applications to target discrimination, classification, imaging and identification

In meticulous detail, a succinct summary of basic electromagnetic wave polarization descriptors, of the various scatterer polarization transformation matrices, and its invariants of the associated optimal matrix polarizations, and of the scatterer descriptive operators is introduced. It is then shown how the five (5) independent matrix parameter for the relative phase mono-static scattering matrix describing an isolated, yet regionally distributed, target in a reciprocal propagation medium can be recovered from (1) amplitude-only, (2) mixed amplitude plus partial phase, (3) complete two-step amplitude-phase measurements. Basic properties of the radar scattering matrix for linear (H, V) and circular (R, L) polarization basis are described in terms of geometrical target features as functions of the specular point surface coordinate parameters, known as gaussian principal, main and related curvature functions. Based upon this succinct background introduction on radar polarimetry, the concepts are applied mainly for the coherent case to various classes of increasing order of sophistication, as defined in detail in the INTRODUCTION, to the problem of radar target handling for the non-cooperative, limited-data case.