| The great potential benefit offered to commercial aviation by the Global Positioning System (GPS) lies in the possibility of inexpensive, seamless navigation from takeoff to touchdown. While this goal is highly motivating, significant technical challenges have existed, the most difficult of which have been associated with navigation during zero-visibility (Category III) precision landing. The severe requirements for accuracy, integrity, continuity, and availability have demanded a new level of GPS navigation system performance. For example, the integrity requirement of 'one undetected navigation failure in a billion approaches' has often been perceived as unattainable using GPS. In response, the central focus of this research has been to establish the viability of high-integrity satellite-based navigation for the precision landing of aircraft.;This dissertation demonstrates that highly precise GPS carrier phase measurements from spacecraft and ground-based pseudolites can provide the basis for high navigation integrity. It is shown that the considerable accuracy margin offered by carrier phase provides leverage for autonomous integrity monitoring aboard the aircraft in the sense that extremely tight fault detection thresholds may be set without incurring high false alarm rates. Furthermore, when placed under the approach path, pseudolites provide the means for real-time cycle ambiguity resolution and ensure the availability of redundant measurements for autonomous integrity monitoring.;Prototype algorithms for airborne kinematic carrier phase processing, including high-speed algorithms for the first high-integrity real-time cycle ambiguity resolution, were developed, implemented and tested. Algorithm performance was verified through an extensive battery of flight tests culminating in 110 successful automatic landings of a United Airlines Boeing 737-300. In addition, the framework of Receiver Autonomous Integrity Monitoring (RAIM) was adapted for application to both cycle ambiguity resolution and kinematic positioning and for the detection of the wide range of navigation system failure scenarios. Navigation integrity and its parametric interrelationship with accuracy, continuity, and availability were quantitatively assessed through analysis, simulation, and flight test. |
