
Langley Research Center, Hampton, Va., has designed three light detection and ranging (lidar) sensors that together can provide all the necessary data for achieving safe autonomous precision landing.
One is a three-dimensional active imaging device, referred to as flash lidar, for detecting hazardous terrain features and identifying safe landing sites. The second is a Doppler lidar instrument for measuring the vehicle velocity and altitude to help land precisely at the chosen site. The third is a high-altitude laser altimeter providing data prior to final approach for correcting the flight trajectory towards the designated landing area.