Future Architectures to Provide Aviation Integrity

Abstract

Ionospheric delay uncertainty creates the largest restriction to the availability of high integrity satellite navigation for today’s single frequency systems. LAAS, WAAS, and the other SBAS providers are limited in their coverage and service levels by the variability of the ionosphere. With the arrival of the new civil signals at L5, comes the ability to directly estimate and remove the ionospheric delay at any point on the Earth. This allows for new architectures exploiting L1 and L5 to bring airplanes within two hundred feet of the ground anywhere on the globe. The FAA has initiated a study panel, called the GPS Evolutionary Architectural Study (GEAS) to look into future architectures to provide this global service. The