Instantaneous Target Velocity Estimation Using a Network of a Radar and Repeater Elements

This paper presents an approach to estimate the true direction of motion and the velocity of a target within a single measurement snapshot. This is achieved by using a single radar sensor in combination with an active repeater element that is operated as a displaced virtual sensor. Coherency between sensor and repeater tag is only obtained by signal processing; on a hardware level both operate incoherently. This setup provides the necessary multi-perspective view on the target at low effort and large freedom of placement. The results of simulations and measurements in the 77 GHz band with one radar sensor and two repeater elements are presented to validate the theory.