SAR Imaging with Automotive Radar: Range Migration Algorithm, Experiment, and Future Directions in Automotive Vehicle

Synthetic Aperture Radar (SAR) imaging with air-borne radar has many applications in remote sensing, surface mapping, and civil infrastructure monitoring. In contrast, the Millimeter wave (mmWave) radars are confined to the automotive industry to fetch information like range, azimuth, and elevation. In this paper, we proposed configuring the mm-wave radar in SAR mode to utilize the availability of multiple transmitters and receivers. The frequency modulated continuous wave (FMCW) radar is ported onto a moving platform, and a range migration algorithm (RMA) is performed to perform SAR imaging. The real-time experiment was conducted using IWR6843ISK radar and explored different configurations like SAR, single-input multiple-outputs SAR (SIMO-SAR), and multiple-input multiple-outputs SAR (MIMO-SAR). In addition to that, the platform movement is also considered by varying the speed from slow to high. The acquired I-Q data is processed using a range migration algorithm (RMA) by following the processing steps like a two-dimensional fast fourier transform (2D-FFT), Stolt interpolation, azimuth compression, and inverse FFT (IFFT). The experimental results reveal that the target detection is accomplished for all the cases. The best results can be obtained for MIMO configuration with a high-speed moving platform. These results can be highly applicable for the automotive industry to perform SAR imaging on SRR radars which are being deployed on the side of the vehicle to monitor the guard rails, crossing vehicles, and VRU.