Thursday, April 24, 2008

NextGen 101: Satellite Based Augmentation Systems (SBAS)

Welcome to Wired!

As our industry enters the new dawn of airspace management and integrated avionic capabilities we at ASIG felt it was appropriate to share the benefit of our experience and know-how with those laymen of our industry who are most directly charged with keeping and maintaining safe skies, the Technical and Flight Operations Managers. We'll start this year's look at the future of Air Traffic Control (ATC) with an intro to SBAS. Satellite Navigation and positioning systems represent the most important technological breakthrough in aviation navigation history. Satellite Based Augmentation Systems (SBAS) refers to geostationary satellites over various regions of the world supported by a network of precisely located ground reference stations. These ground stations monitor, collect and process satellite signals and send this information to ground-based master stations. The Wide Area Augmentation System (WAAS) master stations develop a WAAS correction message that is relayed to airborne, WAAS enabled aircraft via geostationary satellites.

This highly precise SBAS navigation system improves accuracy, availability, and integrity of GPS-derived position thereby increasing the navigation capacity for all classes of aircraft in all phases of flight. When operating in North America, WAAS equipped aircraft achieve a dramatic improvement in signal availability over traditional GPS sensors. This is due to the use of WAAS geostationary satellites as distance ranging sources. The large gain in availability eliminates the need to perform GPS integrity predictions (aka: RAIM) prior to departure. This allows for easier flight planning and fewer delays or canceled departures.

All Satellite Based Augmentation Systems (SBAS) are regional systems. There is currently an international effort to establish cooperation among SBAS providers so their implementation becomes part of a seamless worldwide navigation system. ASIG's integrated flight decks allow even classic and contemporary generation aircraft to be compatible with all international satellite-based systems. Whether operating within Europe's (EGNOS), Japan's (MSAS) or India's (GAGAN) system you can be assured of global dispatch ability. Working with our clients and the end-user operator(s) our integrations are designed and developed with forward-fit future compliance with the standards established in RTCA DO-229D. ASIG's designs largely feature off-the-shelf (COTS) equipment for efficiency of integration and ease the procurement effort of Line Replaceable Units (LRUs). Our retrofits and architecture provide all the necessary capabilities that will extend into Canadian airspace as well. NAV CANADA has participated in the development of a Global Navigation Satellite System (GNSS) by proposing a Canadian WASS (CWASS) that supplements the United States installation of WAAS by adding additional reference stations within Canada in order to increase coverage across North America. Flying in one of ASIG's fully integrated cockpits provides virtually seamless international satellite-based navigation for a fraction of the implementation cost of manufacturer Service Bulletin modifications.

Until next time stay 5x5, Mission Ready & Wired!
To learn more about our approach to aircraft modernization or the products and services available from Avionics & Systems Integration Group (ASIG), please visit us online at, via email at, or contact us direct at 866.890.ASIG [2744].