Reflection Signal Strength Incident Angle Dependency Evaluations of a Small Object on an Airport Runway Using 96 GHz Foreign Object Debris Detection Millimeter-Wave Radar

The airport runway foreign object debris (FOD) detection system automatically detects small FODs that could damage aircraft. We have been developing an FOD detection system based on an optically connected 96 GHz distributed-type millimeter-wave radar sensor. In this study, to confirm the suitable radar sensor installation height, the incident angle dependencies of the reflection signal strength from the small objects are experimentally evaluated at an actual airport. Metallic cylinders of 1 cm, 2 cm, and 3 cm in height are employed for the runway measurements. The results confirm that the reflection signal power from the 1 cm metallic cylinder is the most affected by lower incident angles. In addition, the reflection power of all metallic cylinders is reduced below an incident angle of 2.5 degrees.