Contours and Antenna Beams

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.

Volume Graphics

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).
Minimum Displayed Gain	Use to configure the minimum gain to be displayed as part of the volume graphics. To ensure that the gain volume is displayed properly, make sure that this value is less than the maximum gain of the antenna. Note that only gain values between the minimum and maximum values will be included in the gain volume graphics. Minimum Displayed Gain 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).

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.

Pattern

Azimuth and Elevation

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. 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.

Coordinate System

Select the coordinate system for the antenna pattern resolution for contouring. It can be one of three antenna coordinate systems in STK: polar, rectangular, or spherical Az/El.

Gain Coloring

There are two methods for specifying how colors will be added to show antenna gain:

Min to Max Method

Select this method and specify the Color Min and Max Color values to create a spectrum-pattern, color ramp of the antenna gain.

Explicit Levels Method

Select this method and specify the following parameters to define individual antenna gain levels.

Parameter	Description
Relative to Maximum	If selected, antenna gain level values are assumed to be relative to the maximum value. For example, if the maximum gain value is 30 dB, a gain value of -5 would plot a 25 dB gain line.
Level Adding	Define the number and type of gain levels to be displayed. Select an Add Method and enter the information appropriate to that method: Start, Stop, Step. Enter a Start contour value, a Stop value, and a Step value. Use the Add Level button to generate gain values beginning with the Start value and incrementing by the Step specified until the Stop value is reached or exceeded. Explicit. Enter individual gain values. Use the Add Level button to add the new gain value to the list of existing gain values.
Level Attributes	You can define a color for each individual level by clicking the color field associated with a level in the list.

Parameter

Description

Relative to Maximum

If selected, antenna gain level values are assumed to be relative to the maximum value. For example, if the maximum gain value is 30 dB, a gain value of -5 would plot a 25 dB gain line.

Level Adding

Define the number and type of gain levels to be displayed.

Select an Add Method and enter the information appropriate to that method:

Start, Stop, Step. Enter a Start contour value, a Stop value, and a Step value. Use the Add Level button to generate gain values beginning with the Start value and incrementing by the Step specified until the Stop value is reached or exceeded.
Explicit. Enter individual gain values. Use the Add Level button to add the new gain value to the list of existing gain values.

Level Attributes

You can define a color for each individual level by clicking the color field associated with a level in the list.