Displaying an Ellipsoid

To display an ellipsoid, STK reads covariance data from an external ephemeris file (*.e). (The covariance data is located at the end of the ephemeris file.)

To load sample covariance data from an external ephemeris file, do the following:

1. Create a new scenario with an Analysis Period of 01 Jul 2006 12:00 UTCG to 02 Jul 2006 12:00 UTCG.
2. Insert a satellite using the Insert Default method.
3. Right-click the satellite in the object browser and select Properties.
4. Open the Basic Orbit properties page for the satellite and change the propagator to StkExternal.
5. Click the Filename browse button and browse to the <STK install folder>\Data\Resources\stktraining\text\.
6. Select Covariance_Example.e. (The epoch date in the file is 01 Jul 2006 12:00, which matches the date entered in step 1.)
7. Open the 3D Graphics Model properties page for the satellite and set Log Scale to 0.0 (true scale). This will avoid the exaggerated-scale model from obscuring the covariance ellipsoid.
8. Bring up the 3D Graphics Covariance properties page for the satellite and select Show in the Position Ellipsoid field.
9. Animate the scenario. You should see the ellipsoid encompassing the satellite.