Feature extraction of SAR targets consisting of trihedral and dihedral corner reflectors

The authors study feature extraction of targets, consisting of both trihedral and dihedral corner reflectors, via synthetic aperture radar (SAR). A mixed data model is introduced to describe the target features. The Cramer-Rao bounds (CRBs) for the parameter estimates of the data model are also derived. Two algorithms, the FFTB (fast Fourier transform based) algorithm and the NLS (nonlinear least squares) algorithm, are devised to estimate the model parameters. Numerical examples show that the parameter estimates obtained with both algorithms reach the CRBs as the SNR (signal-to-noise ratio) increases. The parameter estimates obtained with the NLS algorithm start to achieve the CRB at a lower SNR than those with the FFTB algorithm, while the latter algorithm is computationally more efficient