Define the basic properties of a planet
Define <PlanetObjectPath> {Method} <Parameters>
The Define command allows you to define a planet and its ephemerides, by indicating the {Method} by which the planet will be defined and supplying the <Parameters> necessary to do so. Valid {Methods} and their associated <Parameters> are outlined below.
| {Method} | <Parameters> |
|---|---|
| CentralBody | {CBName} [{EphemerisSource}] [Rename] |
| File | "<FilePath.pe>"
Specify a planet ephemeris file, with a .pe extension. |
{CBName} can be the name of any registered central body. Valid values for the optional {EphemerisSource} parameter are outlined in the following Table:
| {EphemerisSource} | Description |
|---|---|
| Default | Use STK's internal definition of the celestial body to generate ephemeris. By default, STK's internal definition uses the DE file if available. |
| JPL | DE430 database: ephemeris for each planet in the solar system plus Pluto, the Sun, and the Earth's Moon. Ephemerides, supplied by JPL, cover a time span from 1960 to 2060. |
| SPICE | Use SPICE ephemeris file (*.bsp) has been loaded for this planet. All SPICE ephemeris files in the <STK install folder>\STKData\Spice and the <STK user area>\Config\Spice directories are loaded automatically when STK starts. |
| Analytic | Use an analytic propagator. Available when orbital elements are known for the celestial body about its parent. |
Use the optional Rename parameter if you want the Planet's name to be the same as that of the body it represents (e.g. you want to call Mars "Mars").
Note: The JPL option provides the location of the barycenter of a planetary system, whereas the SPICE toolkit option provides the location of the planet's center.
Define */Planet/Planet1 CentralBody Jupiter
If activated, Connect returns an acknowledgement message.
This command belongs to the following group(s):
9.0
STK Programming Interface 11.0.1