TECHNOLOGIES FOR AUTOMATING ROTORCRAFT NAP-OF-THE-EARTH FLIGHT

This paper reviews the technologies required for automating rotorcraft nap-of-the-earth flight, where the use of natural obstacles for maski ng from the enemy is intentional and the danger of undesirable obstacl es such as enemy traps is real. Specifically, the automatic guidance s tructure is modeled by three decision-making levels: the far-field mis sion planning and the mid-field terrain-masking trajectory shaping are both driven by stored terrain data, whereas the near-field obstacle d etection/avoidance is driven by real-time, on-board sensor data. This paper summarizes the far-field and mid-field accomplishments, and repo rts on the status of recent efforts in obstacle detection and avoidanc e development. Obstacle detection is based primarily on passive imagin g sensors for the desirable properties of covertness and wide field of view, although active sensors are included in the structure to provid e the needed high resolution for thin-wire detection. An extensive lis t of references, though not exhaustive, is provided.