NLOS (Non-Line-of-Sight) Radar refers to radar systems designed to operate effectively in scenarios where direct line-of-sight visibility between the radar transmitter and the target is obstructed or limited. Traditional radar systems rely on the direct reflection of signals from the target, assuming a clear line of sight. In many real-world situations, obstacles such as buildings, terrain, or environmental conditions can block or scatter radar signals, making it challenging to detect targets. NLOS radar technology plays a critical role in addressing the challenges posed by obstructed line-of-sight scenarios, extending the applicability of radar systems to a broader range of operational environments.


Mosaic: Leveraging Diverse Reflector Geometries for Omnidirectional Around-Corner Automotive Radar

A large number of traffic collisions occur as a result of obstructed sight lines, such that even an advanced driver assistance system would be unable to prevent the crash. Recent work has proposed the use of around-the-corner radar systems to detect vehicles, pedestrians, and other road users in these occluded regions. Through comprehensive measurement, we show that these existing techniques cannot sense occluded moving objects in many important real-world scenarios. To solve this problem of limited coverage, we leverage multiple, curved reflectors to provide comprehensive coverage over the most important locations near an intersection. In scenarios where curved reflectors are insufficient, we evaluate the relative benefits of using additional flat planar surfaces. Using these techniques, we more than double the probability of detecting a vehicle near the intersection in three real urban locations and enable NLoS radar sensing using an entirely new class of reflectors.