SBAS Corrections
Satellite Navigation
138
User Manual 1178.6379.02 ─ 01
Pseudorange calculation
The pseudorange
τ
SV
is a function of the range
ρ
SV
and the corrections:
τ
SV
=
ρ
SV
+
Δρ
SV
+
Δ
Iono
SV
+
Δ
Tropo
SV
-
Δ
t
SV
.
Where the range
ρ
SV
is:
ρ
SV
=
√
[(x
RX
- x
SV
)
2
+ (y
RX
- y
SV
)
2
+ (z
RX
- z
SV
)
2
]
The SV position (x
SV
, y
SV
, z
SV
) is the sum of the ephemeris position (x
eph
, y
eph
, z
eph
) and
the long-term corrections (
Δ
x
LT_corrections
,
Δ
y
LT_corrections
,
Δ
z
LT_corrections
), for example.
x
SV
= x
eph
+
Δ
x
LT_corrections
SBAS correction impact on the logged data
SBAS corrects the pseudorange, satellites and receiver position values. If data logging
is used, the logged values include the corrections. The logged data can deviate from
the expected not corrected parameters.
13.3 How to Generate SBAS Corrections
Activating SBAS
► Select "System Configuration > Systems&Signals" >
"SBAS (e.g. EGNOS) > On"
.
Generating SBAS correction automatically to augment current signal errors
1. For GPS satellites, change the satellite's clock and orbit parameters in the broa-
casted navigation message to simulate signal errors.
For example, define a satellite's clock error for the a
f0
parameter:
Δ
a
f0
= a
f0,simulated
- a
f0,broadcasted
2. Enable SBAS.
How to Generate SBAS Corrections
