Visual-reliefometric navigation algorithm for an aircraft

This paper presents a novel algorithm for visual-terrain-based positioning of an unmanned aerial vehicle (UAV). The proposed method leverages a comparison between reference geophysical terrain data and real-time measurements from an altimeter and an optical camera, in addition to incorporating information from flight path angle sensors and airspeed sensors. Analytical expressions are provided to determine the required resolution of the reference maps as a function of the measurement accuracy. To evaluate the performance and advantages of the algorithm, a simulation study was conducted using MATLAB. The resulting plots illustrate the coordinate determination errors of the UAV for various reference map sizes. The computational efficiency of the algorithm is achieved through the use of only basic mathematical operations of bitwise shifts, additions, subtractions, and convolution operations for terrain data.