Optimisation methods in radar polarimetry

There are several methods available for the calculation of optimum polarisations in radar scattering. These are target specific transmit and receive antenna polarisations which are used to enhance or suppress radar backscatter for the purposes of improved detection or contrast enhancement. There has been interest in obtaining optimum states for distributed targets such as clutter and hydrometeors. In such cases the object cannot be represented by a single scattering matrix, but instead a second order statistical representation is required. This is obtained from the target Mueller matrix, covariance matrix or coherency matrix, all of which contain the same basic information on correlation properties of the scattering medium. The author outlines a classification of these various methods and discusses their advantages and disadvantages