The Attitude Sphere

The attitude sphere is a visualization aid that STK can display in the 3D Graphics and 3D Attitude Graphics windows. It is a powerful tool for understanding an object's attitude and tracking attitude changes over time. You can combine the attitude sphere with vector display, as depicted in the figure below.

To define and display an attitude sphere for an object, open the object's 3D Graphics properties and select the Attitude Sphere page. The options and parameters on this page are described in this topic.

Basic setup

Select Show to display an attitude sphere. You can then set the following parameters:

Parameter	Description
Sphere Color	The color for the sphere's grid lines
Zero Deg Color	The color for the sphere's equator and prime meridian
Spacing	The initial spacing, in degrees, between grid lines
Min Spacing	The minimum spacing, in degrees, to maintain between grid lines when the attitude sphere increases in size due to zooming in or resizing of the window
Max Spacing	The maximum spacing, in degrees, to allow between grid lines when the attitude sphere decreases in size due to zooming out or resizing of the window
Label Type	Display latitude and longitude values on all grid lines, on every other grid line, or on none of them
Label Color	The color for latitude and longitude labels
Font Size	The font size for latitude and longitude labels
Zero Deg Line Width	The width of the equator and prime meridian lines
Grid Line Width	The width of the grid lines
Frame	Click Select... and choose a coordinate frame for the attitude sphere
Scale	Enter a logarithmic scaling factor for the sphere or use the slider to select one
Scale Relative to Model	Select this option to set the sphere's size relative to the scale defined on the Model page
Show Transparent Lines	Select this option to have new grid lines fade in when the sphere is resized

Advanced options

Click Advanced on the Attitude Sphere page to access the following parameters:

Parameter	Description
Pixel Threshold	The resolution, in pixels, used to determine whether to add or remove grid lines as the sphere increases or decreases in size
Label Point Size	The size of points appearing next to grid line labels
Fade Level	Enter a percent value or use the slider to specify the extent to which grid lines fade as a function of their distance from the viewer

Projections

You can project the position of central bodies and other objects of interest onto the attitude sphere. Select an object in the Projections list and set the options described in the table below.

A sensor's projection of its parent object on the attitude sphere does not take into account any translation offsets from the center of the parent object.

Option	Description
Name	The name of the object
Show	Select this option to display a projection of the object
Label	Select this option to display a label identifying the object
Color	The projection's color For a planet or star object, the projection color is the same as the color of the object.
Width	The width of the projection's line
Volume	Select this option to display the projection in three dimensions
Point Size	If the projected object is a star, enter a number to specify the size of the point representing it