Aircraft-protection radar for use with atmospheric lidars

A modified X-band radar system designed to detect aircraft during atmospheric lidar operations is described and characterized. The capability of the radar to identify aircraft approaching from a variety of directions was tested, and first detections were found to occur between the -10 and -3 dB perimeters of the gain hornʹs antenna pattern. A model based on the radar equation projects the performance of the radar for different sizes of aircraft and at different altitude levels. Risk analysis indicates that the probability of accidently illuminating an aircraft with the laser beam during joint lidar-radar operations is low.