Role of Time and Frequency in Egnos (European Geostationary Navigation Overlay System)

摘要

The European Geostationary Navigation Overlay System (EGNOS) is being developed in Europe to provide GPS and GLONASS regional augmentation services to aviation, maritime, and land users. EGNOS will provide the following services: (1) GEO-based GPS-like Ranging signals to improve the availability and continuity of GPS and GLONASS navigation services. (2) Ground Integrity Channel (GZC) to improve the integrity of GPS- and GLONASS-based navigation and position determination for safety-critical applications. And (3) Wide-Arm Differential corrections WAD to improve the accuracy of GPS-SPS and GLONASS. Additionally, EGNOS will disseminate accurate time to users, synchronized to GPS, GLONASS, and UTC time scales. The paper provides an overview of EGNOS ground-segment architecture, gives requirements related to time aspects, and describes ,preliminary analysis and performances through test trials. It also covers initial results achieved in the frame of the EURIDIS program, conducted by CNES, after several months of measurements.