SBAS Corrections
Satellite Navigation
154
User Manual 1178.6379.02 ─ 01
The fast corrections contain the fast correction parameters of MT 2, 3, 4 and 5.
The four messages MT 2, 3, 4 and 5 carry information on the following:
● The issue of data fast correction (IODF)
● User Differential Range Error Indicator (UDREI) and the UDRE
● The coarse integrity "use/don't use" alarm ("Alert" flag)
● The Pseudo Range Correction (PRC) per PRN for a set of up to 13 PRNs
Table 13-6: UDRE,
σ
2
UDRE
and GPS URA as a function of UDREI
UDREI
UDRE, m
σ
2
UDRE
, m
2
GPS URA*
0
0.75
0.0520
2
1
1.0
0.0924
2
2
1.25
0.1444
2
3
1.75
0.2830
2
4
2.25
0.4678
2
5
3.0
0.8315
3
6
3.75
1.2992
3
7
4.5
1.8709
4
8
5.25
2.5465
5
9
6.0
3.3260
5
10
7.5
5.1968
5
11
15.0
20.7870
15
12
50.0
230.9661
10
13
150
2078.695
11
14
not monitored ("NM")
not monitored ("NM")
5**
(average accuracy)
15
Do not use ("DNU")
Do not use ("DNU")
15
Do not use ("DNU")
*) If "Error Correction Mode = Replay Historical Data and Sync Atmosphere & SV
Errors" is enabled, the GPS URA values are automatically set.
**) for UDREI = 14 (not monitored), the GPS URA value is set to average accuracy, i.e.
URA = 5.
Settings:
Fast Correction Data Parameters
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Display
Sets the parameter whose variation over the 24-hour time period is indicated on the
plot.
SBAS Settings
