What is MSAS?
- The Multi-functional Satellite Augmentation System is a Japanese satellite based augmentation system (SBAS) commissioned on September 27, 2007.
How does MSAS work?
- Similar to WAAS and EGNOS, the MSAS system consists of a single Dual PRN geostationary satellite and a network of ground stations.
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A total of 8 stations are linked together to create the
MSAS ground network consisting of:
- 4 GMS (Ground Monitor Stations) - collect information on US GPS and MTSAT signals,
- 2 MCS (Master Control Stations) - calculate and transmit precise correction data to MTSAT satellites (also serve as additional GMS stations),
- 2 MRS (Monitor and Ranging Stations) - correct orbit determination of MTSAT satellites (decommissioned in February of 2015).
MSAS Service Area
- MSAS currently broadcasts augmentation data only for the US GPS system.
- MSAS service extends primarily to Japan and surrounding areas.
MSAS Satellite Map
| Satellite Name | PRN | NMEA | Location |
| QZS-3 (Michibiki-3) | 129 | 42 | 127.0°E |
| QZS-3 (Michibiki-3) | 137 | 50 | 127.0°E |
- PRN is the satellites actual Psuedo-Random Noise code.
- NMEA is the satellite number referenced by most GPS receivers (NMEA = PRN - 87).
- View a list of available SBAS satellites.
Do I need MSAS?
- Unless you will be piloting an aircraft over Asia any time soon, probably not. However, if your Garmin GPSr is WAAS/EGNOS enabled, it may also be able use MSAS to more accurately plot your position on Earth, so why not? Besides, you didn't buy a GPS receiver because you thought paper maps and a compass were 'close enough', now did you?
