SBAS Corrections
Satellite Navigation
137
User Manual 1178.6379.02 ─ 01
tioning accuracy of the receiver. If, for example, the receiver under test does not sup-
port SBAS, a degradation of its positioning performance may be observed.
Apply SBAS corrections to compensate for errors in the navigation messages and thus
improve simulation accuracy only if errors are simulated.
SBAS error correction data source
There are two ways to define the content of the generated SBAS signal:
●
Automatically
SBAS corrections are calculated automatically, from and for the current satellite's
configuration. As with the constellation and navigation message data, there is no
need to load files with augmentation messages files.
This mode is the default SBAS correction mode ("Error Correction Mode > Gener-
ate Corrections Automatically").
●
User-defined
SBAS corrections are configurable, in terms of data source and content.
Corrections are extracted from
*.nstb
or
*.ems
files.
This mode has to activated ("Error Correction Mode > Replay Historical Data/
Replay Historical Data and Sync Generate Corrections Automatically").
Error correction modes
SBAS corrections are calculated in three different modes, as set with the parameter
on page 141. Refer to the description for details.
Biases and corrections
The following corrections are applied automatically:
● Δ
Iono
SV
Vertical delay values, according to the ionospheric grid, broadcasted in the SBAS
messages
● Δ
Tropo
SV
Corrections, as defined by MOPS-DO-229D
● Δρ
SV
=
Δρ
Fast_corrections
Pseudorange bias corrections are the pseudorange corrections retrieved from the
SBAS fast correction data ("PRC")
● Δ
t
SV
=
Δ
t
clk
+
Δ
t
LT_corrections
Clock corrections calculated as the sum of:
–
The clock bias broadcasted by the SV itself (
Δ
t
clk
)
–
The corrections
Δ
t
LT_corrections
retrieved from the SBAS long-term correction data
("
δ
af0", "
δ
af1")
● Δ
x
LT_corrections
,
Δ
y
LT_corrections
,
Δ
z
LT_corrections
Correction information on the GEO satellite location retrieved from the SBAS long-
term correction data ("
δ
x/
δ
y/
δ
z")
These corrections are used for the pseudorange and range calculations.
About Errors Correction
