Autonomous Airborne Video-Aided Navigation

We present an autonomous airborne video-aided navigation system that uses video from an onboard camera, data from an IMU, and digitally stored georeferenced landmark images. The system enables self-contained navigation in the absence of GPS. Relative position and motion are tracked by comparing simple mathematical representations of consecutive video frames. Periodically, a single image frame is compared to the landmark image to determine absolute position and correct for any possible drift or bias in calculating the rela- tive motion. This paper describes the computational approach, test flight hardware, and test results obtained using actual flight data. The techniques are designed to be used for UAVs, cruise missiles, or smart munitions, and provide a cost effective system for navigation in GPS-denied environments.