Radar-based Near Field Environment Perception using Back Projection Algorithm

Radar-based high-resolution environment perception of close targets is facing challenges in terms of its bi-static antenna aperture configuration, where transmitting and receiving patches are separated. In the near field the different travel times occur at individual receive antennas. This time delay results in position errors of targets in the closer sensors' environment using standard radar signal processing. Therefore the antenna configuration needs to be taken into account in raw data signal processing. This paper presents the application of a back projection algorithm to frequency-modulated continuous wave (FMCW) radar for increasing target localization in the automotive field. Therefore, multi-radar sensor measurements illuminating a real target vehicle equipped with an RTK-GPS reference sensor system were carried out on a test area. The standard radar signal processing give evidence of an increased localization error for targets illuminated under large azimuthal angles in the sensors' near field. Applying the BPA approach has high relevance for the application of correction methods.