Performance Analysis of GPS Positioning Using WAAS and EGNOS

With the growing demand for accurate and reliable worldwide differential GPS positioning, there has been a significant move towards the use of real-time GPS augmentation systems with wide area differential positioning capabilities. The US Wide Area Augmentation System (WAAS) and the European Geostationary Navigation Overlay system (EGNOS) are good examples of such a move. While these augmentation systems are developed to provide differential corrections and integrity data for satellite-based aviation, their signal will be available free of charge to all other non-aviation satellite positioning users in the respective coverage areas. Accordingly, non-aviation GPS users with WAAS/EGNOScapable receivers will be able to do differential positioning across the United States and Europe with a free differential signal and achieve real-time 2-to-3 meter positioning. The Ashtech¤ G12“ and GG24“ receivers have been modified to track WAAS and EGNOS geostationary satellites and utilize their differential corrections in the navigation solution. This paper presents DGPS performance results using the newly modified receivers with the WAAS and EGNOS signals.