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MSAS Performances
| MSAS | |
|---|---|
| Title | MSAS Performances |
| Author(s) | GMV. |
| Level | Basic |
| Year of Publication | 2011 |
The Multi-functional Satellite Augmentation System (MSAS) is the Japanese SBAS System: a GPS Augmentation system with the goal of improving its accuracy, integrity, and availability, and that uses the Multifunctional Transport Satellites (MTSAT) owned and operated by the Japanese Ministry of Land, Infrastructure and Transport and the Japan Meteorological Agency (JMA). Tests had been accomplished successfully, and MSAS for aviation use was commissioned on September 27, 2007.[1]
MSAS receives GPS signal at the Ground Monitor Stations and the Monitor & Ranging Stations, checks operational status of GPS, analyze GPS error and ionospheric delay, and then broadcasts augmentation information through MTSAT (Multi-functional Transport Satellite)[2] from the Master Control Stations. Those satellites, MTSAT, broadcast the correction messages back to Earth, where MSAS-enabled GPS receivers use the corrections while computing their positions to improve accuracy.
MSAS Performances
MSAS for aviation use was commissioned on September 27, 2007. MSAS provide service for air navigation:
– 24hours a day, 7days a week.
– Operational Information is provided as NOTAM. [3]
– Use for En-route through Non Precision Approach (NPA) phase of flight (Performance improvement plan under development).
Performances are usually described in terms of accuracy, integrity, availability and continuity. The MSAS Performance Requirements vs observed Performances for En-route through Non Precision Approach (NPA) phase of flight are:[4]
• Horizontal Accuracy (95%)
– Required : Less than 220m (with SA on)
– Observed value is less than 2.2m
• Integrity (Probability of HMI)
– Required : Less than 1x10-7/hour
– Fault Tree Analysis leads 0.903x10-7/hour
• Availability
– Required : More than 99.9%
– Observed : 99.926%
Due to the fact that MTSAT signal are broadcast through the majority region of Asian/Pacific, and there are 2 Monitor MTSAT stations in Hawaii (USA) and Camberra (Australia), the MSAS service area could be easilly expanded if more GMS stations would be installed in MTSAT coverage area.