Cooperative Synthetic Aperture Radar in an Urban Connected Car Scenario

With the raising interest in automated driving, onboard perception systems are required to perform a wide range of functionalities, from basic emergency braking to mapping of the surroundings. However, current automotive radars are known to suffer from low angular/range resolution and might be unable to meet the high-definition mapping required by high levels of automation. Synthetic Aperture Radar (SAR) systems allow to improve the angular resolution of standard automotive radars, but their imaging performance is constrained by the available bandwidth. In Joint Communication and Sensing (JCS), where the on-board radio is used also to inter-connect road users, cooperation enables SAR performance augmentation thanks to the improved geometric factor, especially for near-isotropic targets (poles, pedestrians, etc.). Furthermore, the combination of communication and sensing allows to trade between bandwidth, cooperation and synthetic aperture so as to optimize the overall JCS performance. In this paper, we propose a cooperative SAR (C-SAR) system for automotive scenarios, where single ego-vehicle SAR images are exchanged with neighboring vehicles thus combined to enhance SAR performance. Preliminary simulations support the proposed idea, enabling SAR imaging improvements in low bandwidth scenarios.