A robust semi-parametric method for feature extraction and SAR image formation of targets consisting of trihedrals and dihedrals

A robust semi-parametric algorithm, referred to as SPAR (Semi-PARametric), is presented for feature extraction and complex image formation of targets consisting of both trihedrals and dihedrals via synthetic aperture radar (SAR). The algorithm is based on a flexible data model that models each target scatterer as a two-dimensional complex sinusoid with arbitrary unknown amplitude and constant phase in cross-range and with constant amplitude and phase in range. The proposed algorithm can be used to effectively mitigate the artifacts in the SAR images due to the flexible data model by attempting to deal with one corner reflector, such as one dihedral or trihedral, at a time. Another advantage of SPAR is that it can be used to obtain initial conditions needed by other parametric target feature extraction methods to reduce the total amount of computations needed. Both numerical and experimental examples are provided to demonstrate the performance of the proposed algorithm.