Assured UAS Navigation with Airborne Laser Range Scanners for Various Phases of Flight

This paper discusses the use of single or dual aperture airborne laser range scanners (ALS) for terrain-referenced UAS navigation (TRN) during various phases of flight including en-route, descent, precision approach and low-altitude operations. With the increasing number of military and commercial UAS application, and the vulnerabilities associated with the Global Navigation Satellite Systems (GNSS), alternative self-contained navigation systems have become of more interest to the UAS community. In addition, the significant developments in the areas of lower size, weight, power and cost (SWaP-C) laser range scanners for the automotive and aerial mapping markets, the ALS has become a more mature and viable option for UAS operations. This paper extends previous work by the authors and discusses various filter mechanizations used to perform ALS-based terrain-referenced navigation in the context of performance-based navigation. It addresses the threat model of the ALS-based navigator and, thus, addresses issues related to the accuracy, availability, integrity and continuity for these methods. Finally, data collected with Ohio University's DC-3 aircraft over Athens, OH and NASA Dryden's DC-8 Flying over Reno, NV will be used to demonstrate the performance of these methods.