Creating and Using Attitude Files

If you select the option of importing and using an external attitude (*.a) file , it will override any target pointing or basic attitude profile during the imported file's time period. To use an external attitude file, check the box labeled 'Override Basic & Target Pointing Attitude for specified times'.

For information on how STK handles differentiation, see Attitude Interpolation and Differentiation in STK.

Importing External Attitude Files

To import a file, click the ellipsis (...) button and browse for a file. The name of the selected file and its Start and Stop Time will display in the Attitude page. For more information on the options available for start and stop times, see Time Options.

The Reload File option enables you to edit the external file and update the attitude profile without having to close the scenario. Simply make the desired edits in the attitude file, save it and click Reload File.

Integrated Attitude

You can generate an external attitude file for a satellite by numerically integrating Euler's equations for the current satellite. Click Generate New File.

Time Period and Epoch

You can edit the Start Time and/or Stop Time to define a period shorter than that defined for the satellite. The Epoch will normally coincide with the Start Time. Otherwise the program will integrate (forward or backward, as appropriate) without saving until it reaches the Start Time; then it will integrate forward and save. For more information on the options available for start and stop times, see Time Options.

Initial Conditions

The Initial Conditions frame lets you specify the initial orientation of the satellite in the Earth Inertial (ECI) frame, using any of three orientation systems:

In the Body Fixed Rates fields, enter the initial angular velocity rates, if any, about the satellite's X, Y and Z axes.

The Initialize from Current Attitude button sets initial conditions on the basis of the settings in the Attitude page of a satellite's Basic properties. In a Multi Segment or Override situation, the attitude applicable at the specified Epoch is selected.

Importing Torque Files

To import an external torque file (*.tq), select the appropriate checkbox and click the ellipsis (...) button to browse for a file.

Output

In the Output frame, enter the path and file name for the Integrated Attitude file, or click the ellipsis (...) button and browse for a path and file.