Real-World Environment
Satellite Navigation
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User Manual 1178.6379.02 ─ 01
To account for these effects, the R&S
SMW enables you to apply antenna patterns,
body masks and to simulate real-life scenarios, like a GNSS antenna placed in a car.
The instrument provides an interface for loading and creating user-defined antenna
patterns and body masks. The antenna patterns and body masks are files with prede-
fined file extension (
*.ant_pat
/
*.body_mask
) and file format as described in
ter A.3, "Antenna Pattern and Body Mask Files"
You can define up to four antennas per vehicle.
Antenna pattern and body mask model
You find a subset of predefined body masks files of some generic vehicular models.
The models are simplified general models based on the following assumptions:
●
All surfaces of the vehicle body are considered as planes
●
Ground reflection is not considered for land vehicles; described is only the top body
of a car, the part from the window to the roof
●
The receiver is placed at the central vertical plane.
A body mask is basically a table with rows of elevation angles in the range +90° to -90°
and columns of azimuth from -180° to +180°. Each table element gives the signal
power attenuation in dB of the incident signal. The predefined body masks have up to
three regions: pass, attenuated pass and non-pass. The resolution of the power
response and carrier phase offsets is up to 1° for both, the elevation and azimuth.
The resulting body mask of a medium-sized car with roof-top as illustrated on
Figure 10-2: Illustration of a medium-sized car with roof-top
Antenna Pattern and Body Mask
