Passive Moving Target Imaging via Generalized Wirtinger Flow

In this paper, we present a method for passive radar detection of ground moving targets using interferometric measurements. We assume the scene is illuminated by a source of opportunity and measure the backscattered signal using a single receiving antenna. We correlate the fast-time measurements from one slow-time pulse to another, then form a linear forward model that is akin to the direction-of-arrival (DOA) problem formulation. We model the range variations induced by moving scatterers as directions of arrival, and use Discrete Fourier Transform (DFT) methods to obtain an estimate of the unknown range variation over each slow-time. We propose an alternating optimization based approach, using the Generalized Wirtinger Flow algorithm to estimate the scene reflectivities. We demonstrate the performance of our method with numerical simulations.