Ground Moving Target Trajectory Reconstruction in Single-Channel Circular SAR

Synthetic aperture radar (SAR) has become an important technique for generating high-resolution images of the ground because of its all-weather capabilities. SAR imaging of stationary scenes is nowadays well mastered. Moving targets induce a delocalization and a defocusing effect in the azimuth direction in a SAR image. This latter effect can be used to detect moving targets, to image them, and to estimate their azimuthal velocity, but the main limitation is the impossibility to estimate the full target velocity vector, because of the Doppler shift dependence on azimuthal position and radial velocity. In this paper, we analyze the performances of a method that reconstructs the real target trajectory given the apparent positions of the moving target measured on SAR images acquired along a circular trajectory. We first outline the steps of this trajectory reconstruction methodology, then we perform a mathematical analysis of this methodology, and finally, we present some results on real data, around two French cities.