WIDE AREA AND LOCAL-AREA AUGMENTATIONS - DESIGN TOOLS AND ERROR MODELING

The development of augmentation services, such as EGNOS and WAAS, requ ires careful modelling and simulation before any deployment of equipme nt takes place. The ideal location of ground stations, and the potenti al impact of temporary failures of ground equipment, must be assessed in detail, to ensure that proposed service levels of accuracy and inte grity are maintained at all times. The correct analysis of these param eters can only be achieved if the various wide area processing models, and their respective error propagation characteristics, are suitably simulated. This paper describes the use of a sophisticated and versati le suite of GNSS analysis tools in recent studies. It describes the in corporation of realistic error budgets for WADGPS and LADGPS correctio ns, and the potential use of different combinations of GPS, GLONASS, g eostationary and other satellites in both GNSS-I and GNSS-2.