Analysis of multipath and DOA detection using a fully polarimetric automotive radar

Multipath propagation occurs in many situations of radar measurements in complex environments. The unwanted effects range from amplitude fading over the radar channels and a corrupted direction of arrival (DOA) estimation to the detection of ghost targets in an angle of arrival (AOA) of the multipath direction. Due to the different number of reflections, polarimetric radars are capable to separate certain multipaths from direct paths if the target is known. Furthermore, it is possible to separate objects with different polarimetric features in DOA that are located in the same radial distance to the radar. In this paper, a new approach of DOA detection based on the coherent Pauli decomposition is presented. With this approach, important multipath and DOA effects are analyzed and measurement results at 77 GHz on canonical objects in an anechoic chamber are presented. The results prove the feasibility of the approach and demonstrate the occurring effects.