FAA's Wide Area Augmentation System (WAAS) Summary of Cross-Country Flight Test

The FAA has initiated a program to implement a Wide Area Augmentation System (WAAS) to improve the integrity and accuracy of GPS, and to provide additional ranging sources to improve the availability of satellite navigation for all phases of flight from oceanic, domestic, terminal, nonprecision and precision approaches. The contract for acquiring the WAAS will be awarded in 1995, with operations to start in 1997. The WAAS will start as a U.S. only domestic system and grow into an international system comected to ground reference stations and/or master control stations in other countries. Flight tests are being performed to collect operational data to verify the WAAS concepts before the WAAS is acquired and implemented. Testing of components of the WAAS components concepts started in early 1993, and will continue throughout the acquisition and implementation of the WAAS. The WAAS program is being implemented under an evolutionary test-a-little/implement-a-little concept. This paper will summarize the test data that was colIected during the cross-country flight tests in Jme 1994. The cross-country flight tests were the most comprehensive and far reaching ever accompIished for validating the WAAS. Three aircraft participated in the flight tests: FAA’s Convair 580; FAA’s Aerocommander 630; and Transport Canada’s Challenger 601. The flight tests we= performed at three locations: FAA Technical Center in New Jersey; Crows Landing Naval Auxiliary Landing Field in California: and HamiIton Airport in Ontario, Canada. Three truth sources were used to validate the WAAS: laser trackers at the TechnicaI Center and Crows Landing: Transport Canada’s Self Contained Aircraft Position Determination Equipment (SCAPE); and two frequency GPS receivers working as Time, Space, Position Information (TSPI) systems. These tests have demonstrated for the first time that a single WAAS signal can k used to perform Category I precision approaches at airports on different coasts of the U.S. and Canada.