Volume Graphics | Azimuth and Elevation
The 3D Graphics Attributes page for an antenna, receiver, transmitter, or radar allows you to control the 3D display of contour lines and antenna patterns.
Select Show Boresight Marker to display the boresight marker in the color specified on the 2D Graphics Boresight page.
Select Show Lines under Contour Graphics to display contour graphics in the 3D Graphics window using contour settings defined for the 2D Graphics window.
To display the shape and gain levels of antenna beams, select Show Volume and set the following parameters:
| Field | Description |
|---|---|
| Show as wireframe | Displays the shape of the antenna beam in the 3D Graphics window, using wireframe graphics, with colors indicating the gain level. |
| Gain Scale (per dB) | Increases or decreases the size of the displayed antenna beam (in km) relative to its gain (in dB). |
| Gain Offset | Extends the visible range of the 3D volume by renormalizing the
antenna gain values. For visualization purposes, the 3D antenna
gain is scaled to a distance value (by using the dBs/Km) scale
factor. Because OpenGL does not display negative distance values,
the gain offset allows you to shift the gain into a desired range.
For example, gain patterns with a maximum of 0 dB (all negative
gain pattern values) will not display in the 3D Graphics window. By
using an offset of 20 dB, STK will shift the gain pattern into a
positive region by 20 dB. All new gain values 0 - 20 dB (-20 to 0
dB original values) will display in the 3D Graphics window.
Note: Gain Offset is used for 3D visualization purposes only. It will not alter the original gain values or impact link budget computations. |
The colors in the 3D display of antenna beams run the spectrum from red (highest gain) to violet (lowest gain).
Note: For a multibeam antenna using a Beam Selection Criterion other than Aggregate Active Beams, gain patterns (volume graphics) and 2D and 3D contours correctly depict the orientations of the beams and any relative offsets that have been introduced. When the Aggregate Active Beams criterion is selected, beams with relative offsets are absent from antenna beam patterns, but those beams display properly in 2D and 3D contour graphics.
Controls the antenna pattern resolution for contouring. The finer the resolution, the smoother the graphics appear.
| Parameter | Description |
|---|---|
| Set Azimuth and Elevation Resolution together |
Select to set the azimuth and elevation resolution together. Changes made to Azimuth Resolution and Points fields are applied to the Elevation fields. |
| Resolution |
Enter a value > 0 and <= 30 deg (or the equivalent in another angle unit). This value is the azimuth/elevation angular resolution. |
| Points |
Define resolution in terms of the number of points in the selected range. The Azimuth or Elevation Resolution field is updated to a calculated value based on dividing the range by the number of points. |
| Start / Stop | Define the range of Azimuth and Elevation values.
Note: To display the complete spherical visibility of a hemispherical antenna in the 3D Graphics window, the start value should not be lower than -90 degree and the elevation angle range should be 180 deg. To improve graphics, try decreasing the azimuth and elevation resolution values. |