Experimental Evaluation of Radar Sensor Mounting Height on Vehicle Active Safety Systems Performance

The paper investigates the impact of the height of the automotive radar mounting on the detection performance of vehicle active safety systems, with particular emphasis on multipath interference. Multipath occurs when radar signals are reflected by surfaces such as road pavement, leading to signal oscillations, false detections, or temporary loss of target tracking, which can degrade the reliability of active safety functions. The controlled experiments were conducted using mid- and long-range radar sensors mounted at heights ranging from 20 to 120 cm. Standardized targets, including pedestrian dummies, a Global Vehicle Target, and a corner reflector, were used. Straight-line approach scenarios at 30 km/h on a 250 m test track were evaluated using detection filtering and Radar Cross-Section analysis. The results demonstrate that low mounting heights (20-40 cm) significantly intensify multipath effects, whereas higher mounting positions (100-120 cm) reduce the detectability of low-profile obstacles. The best overall performance across the evaluated sensors in the controlled straight-line test scenario was achieved within the 40-100 cm mounting-height range, providing a good balance of detection reliability for both vehicles and pedestrians.