org.orekit.forces.gravity
Class CunninghamAttractionModel

java.lang.Object
  org.orekit.forces.gravity.CunninghamAttractionModel

All Implemented Interfaces:

java.io.Serializable, ForceModel

public class CunninghamAttractionModel
extends java.lang.Object
implements ForceModel

This class represents the gravitational field of a celestial body.

The algorithm implemented in this class has been designed by Leland E. Cunningham (Lockheed Missiles and Space Company, Sunnyvale and Astronomy Department University of California, Berkeley) in his 1969 paper: On the computation of the spherical harmonic terms needed during the numerical integration of the orbital motion of an artificial satellite (Celestial Mechanics 2, 1970).

Version:

$Revision:1665 $ $Date:2008-06-11 12:12:59 +0200 (mer., 11 juin 2008) $

Author:

Fabien Maussion, Luc Maisonobe, Véronique Pommier-Maurussane

See Also:

Serialized Form

Constructor Summary

CunninghamAttractionModel(Frame centralBodyFrame, double equatorialRadius, double mu, double[][] C, double[][] S)
Creates a new instance.

Method Summary

void	addContribution(SpacecraftState s, TimeDerivativesEquations adder) Compute the contribution of the force model to the perturbing acceleration.
EventDetector[]	getEventsDetectors() Get the discrete events related to the model.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CunninghamAttractionModel

public CunninghamAttractionModel(Frame centralBodyFrame,
                                 double equatorialRadius,
                                 double mu,
                                 double[][] C,
                                 double[][] S)
                          throws java.lang.IllegalArgumentException

Creates a new instance.

Parameters:

centralBodyFrame - rotating body frame

equatorialRadius - reference equatorial radius of the potential

mu - central body attraction coefficient (m³/s²)

C - un-normalized coefficients array (cosine part)

S - un-normalized coefficients array (sine part)

Throws:

java.lang.IllegalArgumentException - if coefficients array do not match

Method Detail

addContribution

public void addContribution(SpacecraftState s,
                            TimeDerivativesEquations adder)
                     throws OrekitException

Compute the contribution of the force model to the perturbing acceleration.

Specified by:

addContribution in interface ForceModel

Parameters:

s - current state information: date, kinematics, attitude

adder - object where the contribution should be added

Throws:

OrekitException - if some specific error occurs

getEventsDetectors

public EventDetector[] getEventsDetectors()

Get the discrete events related to the model.

Specified by:

getEventsDetectors in interface ForceModel

Returns:

array of events detectors or null if the model is not related to any discrete events