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The MSAS Service Volume monitor system (MSV) supports satellite-based air navigation services through monitoring service levels while aircraft use GPS signals for navigation.
The MSV first calculates the protection level obtainable by an aircraft flying at a given time and location using MSAS messages and GPS almanac information, and then graphically shows the calculation result in a way that the situation per airspace can be easily obtained.
The MSV is also capable of displaying related information such as service availability (the portion of time when the protection level is below a threshold during a given period of time) and GDOP (an indicator showing the degree of accuracy obtainable with satellites' geometry to the aircraft). The MSV is furthermore capable of displaying various indicators of RAIM, a method of positioning that ensures integrity using GPS signals only.
Horizontal Protection Level Display
Vertical Protection Level Display
Avalability Display|
Navigation Method Available Displays |
MSAS (APV-I) |
MSAS (ER/NPA) | RAIM |
|---|---|---|---|
| Vertical Protection Level | ○ | ○ | ○ |
| Horizontal Protection Level | ○ | - | - |
| Protection Level/Threshold Difference | ○ | ○ | ○ |
| Availability | ○ | ○ | ○ |
| GDOP | ○ | ○ | ○ |
| APV-Ⅰ Status | ○ | - | - |
Replay time frame can be set with simple operation.
|
Navigation Method Available Displays |
MSAS (APV-I) |
MSAS (ER/NPA) | RAIM |
|---|---|---|---|
| Vertical Protection Level | - | ○ | ○ |
| Horizontal Protection Level | - | - | - |
| Protection Level/Threshold Difference | - | ○ | ○ |
| Availability | - | ○ | ○ |
| GDOP | - | ○ | ○ |