Radar Cross Section Analysis for Road Debris in Automotive FMCW Radar

Road debris is one of the top five causes of serious road traffic accidents in the United States, accounting for about 35,000 crashes every year. For automated driving systems, it is therefore critical to identify and categorize road debris objects reliably. However, only little is known about the behavior and characteristics of road litter in modern automobile radar sensors. An analytical approach for a better understanding of the behavior of road debris in millimeter-wave radar is described on the basis of simple shapes whose RCS characteristics can be calculated. Therefore, a complex-shaped object is divided into essential parts. The RCS of the target is then analyzed concerning the radar frequency and aspect angle. Subsequently, a simulation using a raytracing method for RCS determination validates the analysis of the abstract model. The simulation is then extended to a real object under investigation to further understand of the RCS behavior in the dependency of frequency shifts within the radar signal. Finally, a unique detection method based on the behavior of the RCS characteristics for the researched item is presented for modern vehicle radar systems.