Maximizing Aviation Benefits from Satellite Navigation

This report describes the key elements and results of Stanford University’s contribution to the development of the Wide Area Augmentation System (WAAS), its underlying technologies, and alternative methods to provide global vertical guidance to aircraft. WAAS became the first operational space based augmentation system (SBAS) in July 2003. WAAS augments the Global Positioning System (GPS) with the following three services: integrity monitoring to improve safety; a ranging function to improve availability and continuity; and differential GPS corrections to improve accuracy. WAAS provides the continuity required for enroute and terminal area flight. It also has the integrity required for vertical guidance during airport approach. WAAS also protects the aviation community from uncertainties in GPS satellite replenishment.