Vision-only approach and landing

Landing an aircraft in a remote landing zone autonomously presents several challenges. Firstly, the exact location, orientation, and elevation of the landing zone is not always known; secondly, the accuracy of the aircrafts navigation solution is not always sufficient for this type of precision maneuver. This paper explores a method for estimating the relative position and attitude of the aircraft to marked landing area using only the images from a single camera. The corners of the landing zone are marked with red beacons. The position of these beacons in the camera image are extracted using simple and efficient image processing techniques. Then the location of the corners are used as the measurements for an extended Kalman filter, which is designed to estimate the relative position, velocity, attitude and angular rates of the aircraft. The performance of this navigation algorithm is demonstrated using simulation.