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MSAS Performances

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Title MSAS Performances
Edited by GMV
Level Basic
Year of Publication 2011
Logo GMV.png

The MTSAT Satellite Augmentation System (MSAS) is the Japanese Satellite Based Augmentation System (SBAS) System:[1] a GPS Augmentation system with the goal of improving its accuracy, integrity, and availability. First tests were accomplished successfully, and MSAS system for aviation use was declared operational in September 27, 2007,[2][3][4] providing a service of horizontal guidance for En-route through Non-Precision Approach.[1][2][5] The SBAS signal used to be transmitted from MTSAT (Multi-functional Transport Satellites) operated by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT). The SBAS signal that is made by MLIT is now transmitted from the QZS-3 GEO satellite using the QZSS SBAS transmission service since April 2020.[6]

MSAS Performances

MSAS for aviation use was commissioned on September 27, 2007. MSAS provides service for air navigation with the following characteristics:[5]

  • 24 hours a day, 7 days a week.
  • Operational Information is provided as notice to airmen (NOTAM).[7]
  • Use for En-route through Non Precision Approach (NPA) phase of flight, horizontal guidance only.
  • Service over the Fukuoka Flight Information Region.

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 in 2008 were:[5]

  • 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%

However, as of 2020, the actual performance has improved, achieving [8]:

  • Horizontal Accuracy (95%)
    • < 1.0 m
  • Vertical Accuracy (95%)
    • < 1.6 m

Performance in future evolutions

The following table shows the performance expected for future configurations of the system [9]

MSAS Version Topics
System Update Phase
(2020 - 2023)
Performance equal or higher than MSAS V1.
LPV Performance Phase
(2023 - )
Vertical guidance: LPV operation by two or more GEOs.
High performance IONO software for low latitude magnetic equatorial region based on the research outcome from ENRI.
DFMC Validation Phase
(2017 - )
In support of ICAO SARPs validation activity, the initial performance starts with LPV 200.
ENRI has started DFMC SBAS experiment in 2017 with QZS2.
QZS3 and QZS4 will be used for DFMC SBAS validation.