The Global Postioning System (GPS) is a United States space-based radio-navigation system that provides reliable positioning, navigation, and timing services to users on a continuous worldwide basis-freely available to all. The outstanding performance of GPS over many years has earned the enduring confidence of millions of international users. With its ongoing modernization programme, GPS will continue to provide superb quality and performance in the future.
The Wide Area Augmentation System (WAAS) augments GPS over the North American territory to provide the additional accuracy, integrity and availability needed to enable users to rely on GPS for safety-critical applications, particularly in the field of aviation.
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