The Global Positioning System (GPS) developed by the United States provides users with information on position, velocity, and time worldwide. Together with the European system Galileo, a seamless Global Navigation Satellite System (GNSS) is forming. For more than a decade, Tetra Tech has been providing the Federal Aviation Administration (FAA) with engineering, technical, operations, and satellite support to expand the capabilities of GPS by implementing new satellite navigation technology to make aviation flight safer, more efficient, and more cost-effective. Tetra Tech assisted in the deployment of the Wide Area Augmentation System (WAAS), an FAA-developed system which improves the accuracy, availability, and integrity of GPS.

Initially commissioned in July 2003, WAAS is making a positive difference to aviators across the United States by providing horizontal and vertical navigation assistance for all phases of flight. This includes vertically guided landing approaches in instrument meteorological conditions at all qualified locations.

While enabling improved capacity and safety, WAAS will eventually reduce operations costs for the FAA by enabling the removal of a portion of existing ground-based navigation infrastructure. Tetra Tech continues to provide systems engineering and operations management support to the FAA WAAS program as the system is further improved and satellite navigation technology continues to evolve.