Unambiguous SAR Imaging for Nonuniform DPC Sampling: $\ell_{q}$ Regularization Method Using Filter Bank

Abstract

The displaced phase center antenna (DPCA) technique is a classical method for achieving high-resolution wide-swath synthetic aperture radar (SAR) imaging. For optimum performance, the pulse repetition frequency (PRF) of DPCA SAR systems should satisfy the azimuth uniform sampling condition as far as possible. However, this rigid PRF selection may conflict with the timing diagram for some incidence angles, which usually results in a nonuniform sampling of the synthetic aperture. According to the sparse signal processing theory, this letter proposes a novel DPCA imaging algorithm for the nonuniform displaced phase center sampling. By combining the DPCA data processing operator based on a filter bank with the $\ell_{q}$ regularization scheme, the algorithm can efficiently recover the backscattering coefficients of the observed scene. The experimental results have shown that it is capable of resolving ambiguity and suppressing clutter effectively and is meanwhile insensitive to additive noise.