Wide Area Augmentation System (WAAS) - Program Status

Deborah Lawrence, Deane Bunce, Navin G. Mathur, and C. Edward Sigler

Abstract:	The FAA, the International Civil Aviation Organization (ICAO), RTCA, Inc., and other members of the civilian aviation community have agreed to use Global Navigation Satellite System (GNSS) technology as a key means of next generation radio navigation for aviation. GPS provides a practical starting point for the GNSS. However, GPS cannot satisfy all civil aviation requirements for navigation and landing without augmentation to improve its accuracy, integrity, continuity, and availability. Satellite Based Augmentation System (SBAS) and Ground Based Augmentation System (GBAS) are two augmentation methods to GNSS that are actively pursued by the international community. WAAS, the US version of the ICAO GNSS SBAS, increases the accuracy, continuity, availability, and integrity of GPS data, with concomitant improvements to air traffic system capacity and safety. WAAS also provides aviation service far exceeding that of currently fielded navigational aids. The FAA restated its commitment to WAAS in the Navigation and Landing Transition Strategy released in September 2002. It reinforced WAAS as the cornerstone Area Navigation (RNAV) system for the foreseeable future that can be used for all phases of flight including terminal-area navigation (e.g., departure procedures and standard terminal arrival procedures), en route flight, and instrument approach procedures (approaches with and without vertical guidance). In 2006, the FAA Navigation Directorate developed the FAA Navigation Roadmap. This roadmap identifies WAAS as a key component to achieve optimum runway capacity. WAAS is capable of providing service equivalent to Category I (CAT I) precision approach capability at airports with appropriate infrastructure, and vertically guided approaches to runways without existing instrument procedures. WAAS provides an en-route navigation and approach landing capability (lateral and vertical guidance) that: 1. Improves safety by reducing the likelihood of controlled flight into terrain on approach, 2. Increases the number of runway ends that are eligible for approach procedures, and 3. Provides increased RNAV capability compared to unaugmented GPS. This paper discusses WAAS operational performance requirements along with status of all phases of WAAS program (from 2003 – 2028).
Published in:	Proceedings of the 20th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2007) September 25 - 28, 2007 Fort Worth Convention Center Fort Worth, TX
Pages:	892 - 899
Cite this article:	Lawrence, Deborah, Bunce, Deane, Mathur, Navin G., Sigler, C. Edward, "Wide Area Augmentation System (WAAS) - Program Status," Proceedings of the 20th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2007), Fort Worth, TX, September 2007, pp. 892-899.
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