Global Positioning System Reference
In-Depth Information
99.999
99.99
99.9
99
90
24 Satellites
23 Satellites
22 Satellites
21 Satellites
70
50
30
10
1
0.1
4
5
6
0
1
2
3
7
8
9
10
PDOP
Figure 7.12
Cumulative distribution of PDOP with 5º mask angle cases of 24, 23, 22, and 21
satellites.
−
150
−
120
−
90
−
60
−
30
0
30
60
90
120
150
90
90
60
60
30
30
0
0
−
30
−
30
−
60
−
60
−
90
−
90
−
150
−
120
−
90
−
60
−
30
0
30
60
90
120
150
1- to 5-minute outages
6- to 10-minute outages
11- to 15-minute outages
Figure 7.13
Availability of the GPS constellation with a 5º mask angle with one satellite removed
from the constellation.
rences of these during the day. The majority of the outages are 10 minutes or less.
This constellation provides an availability of 99.903%.
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