Performance of the Northrop Grumman Obstacle Avoidance Laser Radar System (OASYS) has been characterized against various terrestrial targets. OASYS is capable of discriminating and identifying objects from a complementary background as well as producing high-resolution laser radar imagery. Its primary function alerts pilots to obstacles in a helicopter flight path; thus allowing evasive maneuvers to be performed to avoid collision. Primary obstacles encountered are: 1) wires; 2) trees; 3) transmission towers; 4) vertical poles; 5) structures, and; 6) terrain. Of these, wires are the most difficult to detect due to their small cross section. A simple, but very effective object identification algorithm is utilized which unerringly communicates large volumes of detected object data to the pilot, or to the recording computer for later analysis. In the program reported here, laser radar images of various terrestrial objects were obtained and their properties measured. In this manner a database of object signatures, cross-sections, and images is obtained. These objects include: 1) wires of various diameter and reflectivity; 2) trees and vegetation; 3) large and small vertical objects including transmission towers and poles; 4) buildings and structures, and 5) various terrain types.

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