Fully polarimetric generalized likelihood ratio tests (GLRTs) for detecting scattering centers with unknown amplitude, phase, and tilt angle in terrain clutter

We present a family of polarimetric generalized likelihood ratio tests (PGLRTs) which exploit fully polarimetric information in a high resolution application to detect scattering centers in terrain clutter. The detectors are based on a deterministic target model derived from the Huynen parameterization of a scattering matrix. The model is parameterized by target amplitude, absolute phase, and target orientation angle. These parameters, which are unknown in many practical applications, are estimated by the detectors. the PGLRTs may be used to enhance the responses of certain scattering center types relative to others in a given region of interest. Once a scattering center is detected, the ML estimates formed by a PGLRT may be used to further describe the detected target. We implement and analyze the performance of the PGLRTs designed for Gaussian and K-distributed clutter with known covariance. The PGLRT that assumes all three model parameters are unknown is a detector whose performance we show to lie between that of the optimal polarimetric detector and the polarization whitening filter.