An improved ENLCS algorithm based on a quadratic ellipse model for high-resolution one-stationary bistatic SAR

Abstract

ABSTRACTHigh-resolution one-stationary bistatic synthetic aperture radar (BiSAR) data focusing is a challenging task due to the large range cell migration (RCM) and the azimuth-variant Doppler phases. In this letter, an extended nonlinear chirp scaling (ENLCS) based on a quadratic ellipse model is investigated for the one-stationary BiSAR configuration. An analytical relationship of iso-equivalent-sum-of-bistatic-range (iso-ESBR) of azimuth distributed targets is derived after range cell migration correction (RCMC) which is combined by linear range walk correction (LRWC) and keystone transform (KT). Following which, a new quadratic ellipse model is constructed to analyze the azimuth-variant property of the Doppler phases. Based on the new quadratic ellipse model, an improved ENLCS algorithm with new coefficients is derived to accomplish the azimuth equalization for azimuth compression. Simulation results validate the effectiveness of the proposed algorithm.