Joint through-wall 3-D radar imaging and motion detection using a stop-and-go SAR trajectory

Abstract

Through-wall radar research has been very active in recent years, offering possibilities for both motion detection and stationary scene imaging. In this paper, we propose to address both objectives of through-wall radar in a single pass of a vehicle-mounted radar in front of a building of interest, using a stop-and-go synthetic aperture radar (SAR) trajectory. To do so, the vehicle is driven on a straight path approaching the building, it stops for approximately 30 seconds in front of the building, and then accelerates to reach a constant speed for the remainder of the pass. During this time, the radar continuously collects data at a constant pulse repetition frequency. In this paper, we demonstrate that the image quality is not affected by the stop- and-go trajectory provided that we use an estimate of the angle between two consecutive pulses as the weighting function in the imaging algorithms. We show that a walker and a mover, where the former cannot be detected directly in the SAR image, can be detected using simple motion detection schemes.