Package org.orekit.forces.gravity

Class SingleBodyAbsoluteAttraction

java.lang.Object

org.orekit.forces.gravity.AbstractBodyAttraction

org.orekit.forces.gravity.SingleBodyAbsoluteAttraction

All Implemented Interfaces:

ForceModel, EventDetectorsProvider, ParameterDriversProvider

public class SingleBodyAbsoluteAttraction
extends AbstractBodyAttraction

Body attraction force model computed as absolute acceleration towards a body.

This force model represents the same physical principles as NewtonianAttraction, but has several major differences:

• the attracting body can be away from the integration frame center,
• several instances of this force model can be added when several bodies are involved,
• this force model is never automatically added by the numerical propagator

The possibility for the attracting body to be away from the frame center allows to use this force model when integrating for example an interplanetary trajectory propagated in an Earth centered frame (in which case an instance of InertialForces must also be added to take into account the coupling effect of relative frames motion).

The possibility to add several instances allows to use this in interplanetary trajectories or in trajectories about Lagrangian points

The fact this force model is never automatically added by the numerical propagator differs from NewtonianAttraction as NewtonianAttraction may be added automatically when propagating a trajectory represented as an Orbit, which must always refer to a central body, if user did not add the NewtonianAttraction or set the central attraction coefficient by himself.

Author:

Luc Maisonobe, Julio Hernanz

See Also:

• InertialForces

Field Summary

Fields inherited from class org.orekit.forces.gravity.AbstractBodyAttraction

ATTRACTION_COEFFICIENT_SUFFIX

Fields inherited from interface org.orekit.propagation.events.EventDetectorsProvider

DATATION_ACCURACY

Constructor Summary

Constructors

Constructor	Description
SingleBodyAbsoluteAttraction(CelestialBody body)	Constructor.
SingleBodyAbsoluteAttraction(ExtendedPositionProvider positionProvider, String name, double mu)	Simple constructor.

Method Summary

Modifier and Type	Method	Description
<T extends CalculusFieldElement<T>> FieldVector3D<T>	acceleration(FieldSpacecraftState<T> s, T[] parameters)	Compute acceleration.
Vector3D	acceleration(SpacecraftState s, double[] parameters)	Compute acceleration.

Methods inherited from class org.orekit.forces.gravity.AbstractBodyAttraction

dependsOnPositionOnly, getBodyName, getBodyPosition, getBodyPosition, getBodyPVCoordinates, getBodyPVCoordinates, getParametersDrivers

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.orekit.propagation.events.EventDetectorsProvider

getDateDetector, getEventDetectors, getFieldDateDetector, getFieldEventDetectors

Methods inherited from interface org.orekit.forces.ForceModel

addContribution, addContribution, dependsOnAttitudeRate, getEventDetectors, getFieldEventDetectors, getMassDerivative, getMassDerivative, init, init

Methods inherited from interface org.orekit.utils.ParameterDriversProvider

getNbParametersDriversValue, getParameterDriver, getParameters, getParameters, getParameters, getParameters, getParametersAllValues, getParametersAllValues, isSupported

Constructor Details

SingleBodyAbsoluteAttraction

public SingleBodyAbsoluteAttraction(ExtendedPositionProvider positionProvider,
 String name,
 double mu)

Simple constructor.

Parameters:

positionProvider - extended position provider for the body to consider

name - name of the body

mu - body gravitational constant

Since:

13.0

SingleBodyAbsoluteAttraction

public SingleBodyAbsoluteAttraction(CelestialBody body)

Constructor.

Parameters:

body - the body to consider (ex: CelestialBodies.getSun() or CelestialBodies.getMoon())

Method Details

acceleration

public Vector3D acceleration(SpacecraftState s,
 double[] parameters)

Compute acceleration.

Parameters:

s - current state information: date, kinematics, attitude

parameters - values of the force model parameters at state date, only 1 value for each parameterDriver

Returns:

acceleration in same frame as state

acceleration

public <T extends CalculusFieldElement<T>>
FieldVector3D<T> acceleration(FieldSpacecraftState<T> s,
 T[] parameters)

Compute acceleration.

Type Parameters:

T - type of the elements

Parameters:

s - current state information: date, kinematics, attitude

parameters - values of the force model parameters at state date, only 1 value for each parameterDriver

Returns:

acceleration in same frame as state