org.orekit.propagation.semianalytical.dsst.forces

Class DSSTThirdBody

java.lang.Object

org.orekit.propagation.semianalytical.dsst.forces.DSSTThirdBody

All Implemented Interfaces:

EventDetectorsProvider, DSSTForceModel, ParameterDriversProvider

public class DSSTThirdBody
extends Object
implements DSSTForceModel

Third body attraction perturbation to the DSSTPropagator.

Author:

Romain Di Costanzo, Pascal Parraud, Bryan Cazabonne (field translation)

Field Summary

Fields

Modifier and Type	Field and Description
static String	ATTRACTION_COEFFICIENT Name of the single parameter of this model: the attraction coefficient.
static double	BIG_TRUNCATION_TOLERANCE Truncation tolerance for big, eccentric orbits.
static int	MAX_POWER Max power for summation.
static String	SHORT_PERIOD_PREFIX Name of the prefix for short period coefficients keys.
static double	SMALL_TRUNCATION_TOLERANCE Truncation tolerance for small orbits.

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

DATATION_ACCURACY

Constructor Summary

Constructors

Constructor and Description
DSSTThirdBody(CelestialBody body, double mu) Complete constructor.

Method Summary

Modifier and Type	Method and Description
CelestialBody	getBody() Get third body.
<T extends org.hipparchus.CalculusFieldElement<T>> T[]	getMeanElementRate(FieldSpacecraftState<T> currentState, FieldAuxiliaryElements<T> auxiliaryElements, T[] parameters) Computes the mean equinoctial elements rates dai / dt.
double[]	getMeanElementRate(SpacecraftState currentState, AuxiliaryElements auxiliaryElements, double[] parameters) Computes the mean equinoctial elements rates dai / dt.
List<ParameterDriver>	getParametersDrivers() Get the drivers for parameters.
List<ShortPeriodTerms>	initializeShortPeriodTerms(AuxiliaryElements auxiliaryElements, PropagationType type, double[] parameters) Computes the highest power of the eccentricity and the highest power of a/R3 to appear in the truncated analytical power series expansion.
<T extends org.hipparchus.CalculusFieldElement<T>> List<FieldShortPeriodTerms<T>>	initializeShortPeriodTerms(FieldAuxiliaryElements<T> auxiliaryElements, PropagationType type, T[] parameters) Performs initialization prior to propagation for the current force model.
void	registerAttitudeProvider(AttitudeProvider provider) Register an attitude provider.
void	updateShortPeriodTerms(double[] parameters, SpacecraftState... meanStates) Update the short period terms.
<T extends org.hipparchus.CalculusFieldElement<T>> void	updateShortPeriodTerms(T[] parameters, FieldSpacecraftState<T>... meanStates) Update the short period terms.

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.semianalytical.dsst.forces.DSSTForceModel

extractParameters, extractParameters, getEventDetectors, getFieldEventDetectors, init, init

Methods inherited from interface org.orekit.utils.ParameterDriversProvider

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

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

getEventDetectors, getFieldEventDetectors

Field Detail

SHORT_PERIOD_PREFIX

public static final String SHORT_PERIOD_PREFIX

Name of the prefix for short period coefficients keys.

See Also:

Constant Field Values

ATTRACTION_COEFFICIENT

public static final String ATTRACTION_COEFFICIENT

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

See Also:

Constant Field Values

MAX_POWER

public static final int MAX_POWER

Max power for summation.

See Also:

Constant Field Values

BIG_TRUNCATION_TOLERANCE

public static final double BIG_TRUNCATION_TOLERANCE

Truncation tolerance for big, eccentric orbits.

See Also:

Constant Field Values

SMALL_TRUNCATION_TOLERANCE

public static final double SMALL_TRUNCATION_TOLERANCE

Truncation tolerance for small orbits.

See Also:

Constant Field Values

Constructor Detail

DSSTThirdBody

public DSSTThirdBody(CelestialBody body,
                     double mu)

Complete constructor.

Parameters:

body - the 3rd body to consider

mu - central attraction coefficient (i.e., attraction coefficient of the central body, not the one of the 3rd body)

See Also:

CelestialBodies

Method Detail

getBody

public CelestialBody getBody()

Get third body.

Returns:

third body

initializeShortPeriodTerms

public List<ShortPeriodTerms> initializeShortPeriodTerms(AuxiliaryElements auxiliaryElements,
                                                         PropagationType type,
                                                         double[] parameters)

Computes the highest power of the eccentricity and the highest power of a/R3 to appear in the truncated analytical power series expansion.

This method computes the upper value for the 3rd body potential and determines the maximal powers for the eccentricity and a/R3 producing potential terms bigger than a defined tolerance.

Specified by:

initializeShortPeriodTerms in interface DSSTForceModel

Parameters:

auxiliaryElements - auxiliary elements related to the current orbit

type - type of the elements used during the propagation

parameters - values of the force model parameters for state date (1 value for each parameters)

Returns:

a list of objects that will hold short period terms (the objects are also retained by the force model, which will update them during propagation)

initializeShortPeriodTerms

public <T extends org.hipparchus.CalculusFieldElement<T>> List<FieldShortPeriodTerms<T>> initializeShortPeriodTerms(FieldAuxiliaryElements<T> auxiliaryElements,
                                                                                                                    PropagationType type,
                                                                                                                    T[] parameters)

Performs initialization prior to propagation for the current force model.

This method aims at being called at the very beginning of a propagation.

Specified by:

initializeShortPeriodTerms in interface DSSTForceModel

Type Parameters:

T - type of the elements

Parameters:

auxiliaryElements - auxiliary elements related to the current orbit

type - type of the elements used during the propagation

parameters - values of the force model parameters for specific date (1 value only per parameter driver) obtained for example by calling ParameterDriversProvider.getParameters(AbsoluteDate) on force model or AbstractGradientConverter.getParametersAtStateDate(FieldSpacecraftState, ParameterDriversProvider) on gradient converter.

Returns:

a list of objects that will hold short period terms (the objects are also retained by the force model, which will update them during propagation)

getMeanElementRate

public double[] getMeanElementRate(SpacecraftState currentState,
                                   AuxiliaryElements auxiliaryElements,
                                   double[] parameters)

Computes the mean equinoctial elements rates da_i / dt.

Specified by:

getMeanElementRate in interface DSSTForceModel

Parameters:

currentState - current state information: date, kinematics, attitude

auxiliaryElements - auxiliary elements related to the current orbit

parameters - values of the force model parameters at state date (only 1 span for each parameter driver) obtained for example by calling ParameterDriversProvider.getParameters(AbsoluteDate) on force model.

Returns:

the mean element rates dai/dt

getMeanElementRate

public <T extends org.hipparchus.CalculusFieldElement<T>> T[] getMeanElementRate(FieldSpacecraftState<T> currentState,
                                                                                 FieldAuxiliaryElements<T> auxiliaryElements,
                                                                                 T[] parameters)

Computes the mean equinoctial elements rates da_i / dt.

Specified by:

getMeanElementRate in interface DSSTForceModel

Type Parameters:

T - type of the elements

Parameters:

currentState - current state information: date, kinematics, attitude

auxiliaryElements - auxiliary elements related to the current orbit

parameters - values of the force model parameters at state date (only 1 span for each parameter driver) obtained for example by calling ParameterDriversProvider.getParameters(Field, FieldAbsoluteDate) on force model or AbstractGradientConverter.getParametersAtStateDate(FieldSpacecraftState, ParameterDriversProvider) on gradient converter.

Returns:

the mean element rates dai/dt

updateShortPeriodTerms

public void updateShortPeriodTerms(double[] parameters,
                                   SpacecraftState... meanStates)

Update the short period terms.

The short period terms that will be updated are the ones that were returned during the call to DSSTForceModel.initializeShortPeriodTerms(AuxiliaryElements, PropagationType, double[]).

Specified by:

updateShortPeriodTerms in interface DSSTForceModel

Parameters:

parameters - values of the force model parameters (all span values for each parameters) obtained for example by calling ParameterDriversProvider.getParametersAllValues() on force model. The extract parameter method DSSTForceModel.extractParameters(double[], AbsoluteDate) is called in the method to select the right parameter corresponding to the mean state date.

meanStates - mean states information: date, kinematics, attitude

updateShortPeriodTerms

public <T extends org.hipparchus.CalculusFieldElement<T>> void updateShortPeriodTerms(T[] parameters,
                                                                                      FieldSpacecraftState<T>... meanStates)

Update the short period terms.

The short period terms that will be updated are the ones that were returned during the call to DSSTForceModel.initializeShortPeriodTerms(AuxiliaryElements, PropagationType, double[]).

Specified by:

updateShortPeriodTerms in interface DSSTForceModel

Type Parameters:

T - type of the elements

Parameters:

parameters - values of the force model parameters (all span values for each parameters) obtained for example by calling ParameterDriversProvider.getParametersAllValues(Field) on force model or AbstractGradientConverter.getParameters(FieldSpacecraftState, ParameterDriversProvider) on gradient converter. The extract parameter method DSSTForceModel.extractParameters(CalculusFieldElement[], FieldAbsoluteDate) is called in the method to select the right parameter.

meanStates - mean states information: date, kinematics, attitude

registerAttitudeProvider

public void registerAttitudeProvider(AttitudeProvider provider)

Register an attitude provider.

Register an attitude provider that can be used by the force model.

Specified by:

registerAttitudeProvider in interface DSSTForceModel

Parameters:

provider - the AttitudeProvider

getParametersDrivers

public List<ParameterDriver> getParametersDrivers()

Get the drivers for parameters.

Specified by:

getParametersDrivers in interface ParameterDriversProvider

Returns:

drivers for parameters