APPENDIX
AP-6
What Is WAAS?
WAAS, available in North America, is a provider in the worldwide SBAS (Satellite Based
Augmentation System) navigation system. CBAS provides GPS signal corrections to SBAS
users, for even better position accuracy, typically better than three meters. There are three
more SBAS providers, MSAS (Multi-Functional Satellite Augmentation System) for Japan,
EGNOS (Euro Geostationary Navigation Overlay Service) for Europe and GAGAN (GPS
And GEO Augmented Navigation) for India. The illustration below shows the coverage area.
(Accuracy may be affected when using a GEO satellite not within your current location.)
This manual uses “WAAS” for these three providers generically.
WAAS
MSAS
EGNOS
GAGAN
Provider Satellite type Longitude Satellite No.
Intelsat Galaxy XV 133°W 135 WAAS
TeleSat Anik FIR 107.3°W 138
Inmarsat-3-F2/AOR-E 15.5°W 120
Artemis 21.5°E 124
EGNOS
Inmarsat-3-F5/IOR-W 25°E 126
MTSAT-1R 140°E 129 MSAS
MTSAT-2 145°E 137
GAGAN Inmarsat-4-F1/IOR 64°E 127
