You are viewing an old version of this page. View the current version.

Compare with Current View Page History

« Previous Version 3 Next »

 

Interface/Functional Spec

Overview

 
A celestial body model

Description

 
The CelestialBody resource is a model of a celestial body containing settings for the physical properties, as well as the model for the orbital motion and orientation.  GMAT contains built-in models for the Sun, the 8 planets, Earth's moon, and Pluto.  You can create a custom CelestialBody resource to model a planet, asteroid, comet, or moon. 
 
See Also:  SolarSystem, Barycenter, LibrationPoint, CoordinateSystem.

Fields

 
See the User Interface Spec spreadsheet for reference information for fields.  This section is usually empty other than the hyperlink. 
 

GUI

The CelestialBody GUI has three tabs that allow you to set the physical properties, orbital properties, and the orientation model.  CelestialBody resources can be used in ForceModels, CoordinateSystem, LibrationPoints, Barycenters among others.  For a built-in CelestialBody, the Orbit and Orientation tabs are largely inactive and the behavior is discussed further below.  To create create a custom asteroid - as an example of how to create a custom CelestialBody- perform the following steps.

  1. Expand the SolarSystem folder
  2. Right-click the desired central body (here we choose the Sun)
  3. Select Add -> Planet

 

 

 

  
 
The CelestialBody Properties tab is shown above.  GMAT models all bodies as a spherical ellipsoid and you can set the Equatorial Radius, Flattening, and gravitation parameter (Mu) on this dialog, as well as the texture map used in graphical displays.
  
     

The CelestialBody Orbit tab, for a custom CelestialBody, is shown above.  For a built-in CelestialBody, the fields on this panel are inactive and are inherited from the settings on the SolarSystem Resource.  For a custom CelestialBody, the CentralBody field is automatically populated depending upon the central body used when creating the


  

 

For Developer and GUI Tester:  If we add DE421 as Lunar RotatationDataSource, then we will need to make that field active in the panel above.

 

 Remarks


Overview of Celestial Body Orientation Model
 
GMAT asdf.OrientationEpoch = 21545;
GMAT asdf.SpinAxisRAConstant = 0;
GMAT asdf.SpinAxisRARate = -0.641;
GMAT asdf.SpinAxisDECConstant = 90;
GMAT asdf.SpinAxisDECRate = -0.5570000000000001;
GMAT asdf.RotationConstant = 190.147;
GMAT asdf.RotationRate = 360.9856235;
 
Configuring Physical Properties
 
GMAT asdf.Flattening = 0.0033527;
GMAT asdf.EquatorialRadius = 6378.1363;
GMAT asdf.Mu = 398600.4415; 
 
Configuring Orbit Ephemerides
 
GMAT asdf.NAIFId = -123456789;
GMAT Earth.SourceFilename = '../data/planetary_ephem/de/leDE1941.405';
 
Unique fields Earth and Moon
 
GMAT Earth.RotationDataSource = 'FK5IAU1980';
GMAT Earth.NutationUpdateInterval = 60;
Luna.RotationDataSource
 
Use Custom Texture Map
 
GMAT Earth.TextureMapFileName = '../data/graphics/texture/ModifiedBlueMarble.jpg';
 
Resolve:  Are these obsolete
 
GMAT asdf.PosVelSource = 'SPICE';
GMAT asdf.CentralBody = 'Earth';
GMAT asdf.RotationDataSource = 'IAUSimplified';

 

Examples

 

 
Configure a CelestialBody to model the asteroid RQ236.

 

 

 


 
 
Configure a CelestialBody to model the Mars’ moon Phobos.

 

 

 


 
 

Put Comments Here

Description

 
The CelestialBody resource is a model of a celestial body containing settings for the physical properties, as well as the model for the orbital motion and orientation.  GMAT contains built-in models for the Sun, the 8 planets, Earth's moon, and Pluto.  You can create a custom CelestialBody resource to model a planet, asteroid, comet, or moon. 
 
See Also:  SolarSystem, Barycenter, LibrationPoint, CoordinateSystem.

 

  • No labels