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Study of active 3-D terrain mapping for helicopter landings

A feasibility study of an active 3-D terrain mapping system for helicopter landings is presented. The system acquires the 3-D shape of the terrain beneath the helicopter by scanning the terrain with a laser beam and imaging the illuminated spot by two position-sensing devices. The measurement accuracy of the system is assessed, and a Kalman filter for accuracy improvement is devised. The acquired terrain shape is displayed continuously to the pilot on a perspective display, showing both the terrain shape and helicopter spatial position.