We Thought You'd Never Ask...

The Wide Area Augmentation System (WAAS) is a GPS-based navigation and landing system that provides precision guidance to aircraft at thousands of airports and airstrips where there is currently no precision landing capability. Systems such as WAAS are known as satellite-based augmentation systems (SBAS). WAAS is designed to improve the accuracy and ensure the integrity of information coming from GPS satellites.

The FAA is using WAAS to provide a Lateral Navigation/Vertical Navigation (LNAV/VNAV) capability. This capability will facilitate improved instrument approaches to include vertical (glide path) guidance to an expanded number of airports. Concurrently, the FAA will evaluate the approach to achieve Global Navigation Satellite System (GNSS) Landing System (GLS) capability in later years.

Serious Accuracy

WAAS testing in September 2002 confirmed accuracy performance of 1 - 2 meters horizontal and 2 -3 meters vertical throughout the majority of the continental U.S. and portions of Alaska.

The WAAS signal can also be used for many non-aviation applications, as well... not that that matters (grin).

FMI: www.faa.gov