Package org.orekit.forces.gravity

Class NewtonianAttraction

java.lang.Object

org.orekit.forces.gravity.NewtonianAttraction

All Implemented Interfaces:

ForceModel, EventDetectorsProvider, ParameterDriversProvider

public class NewtonianAttraction
extends Object
implements ForceModel

Force model for Newtonian central body attraction.

Author:

Luc Maisonobe

Field Summary

Fields

Modifier and Type	Field	Description
static String	CENTRAL_ATTRACTION_COEFFICIENT	Name of the single parameter of this model: the central attraction coefficient.

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

DATATION_ACCURACY

Constructor Summary

Constructors

Constructor	Description
NewtonianAttraction(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.
<T extends CalculusFieldElement<T>> void	addContribution(FieldSpacecraftState<T> s, FieldTimeDerivativesEquations<T> adder)	Compute the contribution of the force model to the perturbing acceleration.
void	addContribution(SpacecraftState s, TimeDerivativesEquations adder)	Compute the contribution of the force model to the perturbing acceleration.
boolean	dependsOnPositionOnly()	Check if force model depends on position only at a given, fixed date.
<T extends CalculusFieldElement<T>> T	getMu(Field<T> field, FieldAbsoluteDate<T> date)	Get the central attraction coefficient μ.
double	getMu(AbsoluteDate date)	Get the central attraction coefficient μ.
List<ParameterDriver>	getParametersDrivers()	Get the drivers for parameters.

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

dependsOnAttitudeRate, getEventDetectors, getFieldEventDetectors, init, init

Methods inherited from interface org.orekit.utils.ParameterDriversProvider

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

Field Detail

CENTRAL_ATTRACTION_COEFFICIENT

public static final String CENTRAL_ATTRACTION_COEFFICIENT

Name of the single parameter of this model: the central attraction coefficient.

See Also:

Constant Field Values

Constructor Detail

NewtonianAttraction

public NewtonianAttraction(double mu)

Simple constructor.

Parameters:

mu - central attraction coefficient (m^3/s^2)

Method Detail

dependsOnPositionOnly

public boolean dependsOnPositionOnly()

Check if force model depends on position only at a given, fixed date.

Specified by:

dependsOnPositionOnly in interface ForceModel

Returns:

true if force model depends on position only, false if it depends on velocity, either directly or due to a dependency on attitude

getMu

public double getMu(AbsoluteDate date)

Get the central attraction coefficient μ.

Parameters:

date - date at which the mu value wants to be known

Returns:

mu central attraction coefficient (m³/s²)

getMu

public <T extends CalculusFieldElement<T>> T getMu(Field<T> field,
                                                   FieldAbsoluteDate<T> date)

Get the central attraction coefficient μ.

Type Parameters:

T - the type of the field element

Parameters:

field - field to which the state belongs

date - date at which the mu value wants to be known

Returns:

mu central attraction coefficient (m³/s²)

addContribution

public void addContribution(SpacecraftState s,
                            TimeDerivativesEquations adder)

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

The default implementation simply adds the acceleration as a non-Keplerian acceleration.

Specified by:

addContribution in interface ForceModel

Parameters:

s - current state information: date, kinematics, attitude

adder - object where the contribution should be added

addContribution

public <T extends CalculusFieldElement<T>> void addContribution(FieldSpacecraftState<T> s,
                                                                FieldTimeDerivativesEquations<T> adder)

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

Specified by:

addContribution in interface ForceModel

Type Parameters:

T - type of the elements

Parameters:

s - current state information: date, kinematics, attitude

adder - object where the contribution should be added

acceleration

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

Compute acceleration.

Specified by:

acceleration in interface ForceModel

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.

Specified by:

acceleration in interface ForceModel

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

getParametersDrivers

public List<ParameterDriver> getParametersDrivers()

Get the drivers for parameters.

Specified by:

getParametersDrivers in interface ParameterDriversProvider

Returns:

drivers for parameters