A Review of Navigation Algorithms for Unmanned Aerial Vehicles Based on Computer Vision Systems

The article analyzes the works devoted to outdoor navigation of unmanned aerial vehicles (UAVs) in GNSS-denied environments using computer vision systems (optical range cameras). The algorithms addressed are based on matching of UAV-generated images with the available georeferenced terrain images. Images are matched either pixel by pixel, by their key points, or using neural networks. The stages of each algorithm, as well as the accuracy achieved by the authors and the field data used for testing are considered. The paper concludes with a discussion of the capabilities and limitations of the proposed approaches.