The distributed passive radar 3-D imaging and analysis in wavenumber domain

This paper studies the distributed passive radar three-dimensional (3-D) imaging under the 3-D configuration formed by the illuminators of opportunity and the distributed receivers. The echoes received by the distributed channels actually constitute the target wavenumber-domain coverage, whose characteristics such as range, uniformity and compactness greatly affect the inversion performance. Generally, the wavenumber-domain coverage of the passive radar system is small-scale, sparse and nonuniform, in which case the traditional IFFT method becomes invalid. Therefore, we propose a novel imaging method, named Spherical Coordinates Method (SCM). Furthermore, so as to get higher resolution and better imaging quality, a broader, more uniform and compact coverage in wavenumber domain is required and this can be achieved through the following three methods: increasing the number of the receivers, making use of the motion information and optimizing the disposition of the receivers. Numerical simulations verify the effectiveness of the presented method and the rationality of the theoretical analysis.