Orolia GSG-5 Series, User Manual With Scpi Manual, Page: 76 / 392

3.5.8.1 Antenna model
The antenna gain pattern can be specified for each scenario, using a set of pre-defined
antenna models , or by utilizing a user-specified file. The built-in antenna models assume
an omni-directional gain pattern where the maximum gain is to be found towards the
zenith.
The pre-defined antenna models are:
Zero model : Isotropic antenna with a gain of 0 dBic towards all directions. This is the
default.
Patch : Gain pattern approximates TOKO DAK Series patch antenna with maximum
gain +5 dBic. Size of the patch is 25 x 25 mm and ground plane 70 x 70 mm.
Helix : Gain pattern approximates Sarantel SL1200 (GeoHelix-P2) antenna pattern
with maximum gain -2.8 dBic. This is a small helix antenna designed to be embedded
in handheld devices e.g. mobile phones. See http://www.sarantel.com for details.
Cardioid : Gain pattern 1+sin (elevation) with maximum gain +3 dBic.
GPS-703-GGG : Gain pattern approximates Novatel’s GPS-703-GGG antenna with
maximum gain of +5.7 dBic. See
www.novatel.com
for details.
The format used to describe gain patterns is the FEKO pattern file format version 6.1, Far
Field format, File Format 2.0. Gain patterns for various frequencies are to be included in
the same file as separate Solution Blocks. The GSG units expect the result type to be either
Gain or Directivity , and enforces a maximum value of 50 for the No. of Theta/Phi Samples,
with 36 as the recommended choice yielding a 5/10 degree resolution on elev-
ation/azimuth.
The first line of the antenna file is expected to define the File Type. The GSG defines phi 0
degrees, i.e. the x-axis of phi, to point towards the north direction.
3.5.8.2 Lever arm
A lever arm can be specified to separate the antenna position from the body mass cen-
ter of the vehicle: All trajectory movements in the simulation will act on the body mass cen-
ter of the vehicle. By default the antenna is located in this the body mass center position,
pointing upward. To specify that the receiver antenna is
not
located in the body mass cen-
ter position, a lever arm can be configured.
The lever arm settings specify the relative position change in the form of (x, y, z) along the
body axis of the vehicle frame, where the coordinate system XYZ is aligned with the body
mass center frame. At the start of a scenario, the X-axis corresponds to the east/west axes
of the
ENU frame
and the nose is pointing to the north.
The X-axis has a positive direction towards the right side of the sensor. The Y-axis has a pos-
itive direction towards the front of the sensor. The Z-axis has a positive direction towards
the top of the sensor.
60 User Manual GSG-5/6 Series Rev. 27
3.5 "Select" Menu