R&S SMW-K44 User Manual page 137

Satellite Navigation
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
"Error Correction Mode"
Biases and corrections
The following corrections are applied automatically:
● ΔIono
Vertical delay values, according to the ionospheric grid, broadcasted in the SBAS
messages
●
ΔTropo
Corrections, as defined by MOPS-DO-229D
● Δρ
Pseudorange bias corrections are the pseudorange corrections retrieved from the
SBAS fast correction data ("PRC")
●
Δt
Clock corrections calculated as the sum of:
–
–
●
Δx
Correction information on the GEO satellite location retrieved from the SBAS long-
term correction data ("δx/δy/δz")
These corrections are used for the pseudorange and range calculations.
User Manual 1178.6379.02 ─ 01
on page 141. Refer to the description for details.
SV
SV
= Δρ
SV Fast_corrections
= Δt + Δt
SV clk LT_corrections
The clock bias broadcasted by the SV itself (Δt
The corrections Δt
LT_corrections
("δaf0", "δaf1")
, Δy
LT_corrections LT_corrections
retrieved from the SBAS long-term correction data
, Δz
LT_corrections
SBAS Corrections
About Errors Correction
)
clk
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