Aircraft navigation by means of image registration

Most aircraft, whether manned or unmanned, depend on the Global Positioning System (GPS) for navigation. However, GPS signals are susceptible to jamming and spoofing. A researcher recently demonstrated the use of spoofing to take control of a ship in the Mediterranean Sea. By feeding counterfeit signals to the ship, he was able to drive it far off course. All the time, the navigation system reported the vessel was moving calmly along its intended course. The same researcher also demonstrated the ability to spoof unmanned aerial vehicles (UAVs). The purpose of this paper is to demonstrate a navigation system that does not rely on GPS. The only sensor required is a digital camera. The system works by taking a photograph of the ground and georegistering it to a reference image or digital elevation model (DEM) with the GeoMI™ georegistration software. By transferring geospatial information from the DEM to the photo, the system calculates the position and orientation of the aircraft. The process is fast enough to perform in real time and suitable for use as a primary or backup navigation system for aircraft, UAVs, and cruise missiles. For nighttime navigation, the system could be extended to infrared or radar imagery. Experimental results show that navigation accuracies of 2 meters CE90 can be achieved.