R&S SMW-K44 User Manual page 83

Satellite Navigation
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
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
ure 10-2
Figure 10-2: Illustration of a medium-sized car with roof-top
User Manual 1178.6379.02 ─ 01
is given on Figure 10-3.
Real-World Environment
Antenna Pattern and Body Mask
Files", on page 401.
Chap-
Fig-
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