Tech Briefs

Technique for Finding Retro-Reflectors in Flash LIDAR Imagery

Orbital rendezvous and docking of two spacecraft is a topic of continued interest to NASA. For crewed missions, it is frequently the case that the target is cooperative (i.e., is equipped with some sort of navigation aid). If one of the relative navigation instruments is a Flash LIDAR, then this aid may be a suite of retro-reflectors. One of the most difficult aspects of this problem (especially at close range) is finding the retro-reflectors in a Flash LIDAR image amongst a substantial amount of clutter.

A new technique has been developed for autonomously finding the three-dimensional location of candidate retro-reflectors in a Flash LIDAR image. With no a-priori state information, this new approach is capable of finding an analyst-defined number of reflectors. It is effective at rejecting most bright non-reflector objects. This technique, which continues to be developed and tested, has substantially better performance (finds more reflectors, with fewer false positives) than simpler approaches with only a modest increase in computational resources.

The Orion/Multi-Purpose Crew Vehicle is a new crewed vehicle being designed by NASA and Lockheed Martin for piloted exploration missions capable of destinations beyond low Earth orbit (LEO). The vehicle will also maintain the capability to perform rendezvous, proximity operations, and docking (RPOD) with other orbital assets and elements in the exploration architecture. The vision navigation sensor (VNS) is a Flash LIDAR, and will be the primary navigation instrument used by the Orion during the RPOD flight phase. Thus, maturing techniques for finding reflectors in Flash LIDAR imagery of cooperative vehicles is critical to the current Orion relative navigation architecture.

This work was done by John A. Christian of Johnson Space Center. MSC-25237-1