org.orekit.propagation.semianalytical.dsst.forces

Class DSSTJ2SquaredClosedForm

java.lang.Object

org.orekit.propagation.semianalytical.dsst.forces.DSSTJ2SquaredClosedForm

All Implemented Interfaces:

EventDetectorsProvider, DSSTForceModel, ParameterDriversProvider

public class DSSTJ2SquaredClosedForm
extends Object
implements DSSTForceModel

Second order J2-squared force model.

The force model implements a closed-form of the J2-squared perturbation. The full realization of the model is based on a gaussian quadrature. Even if it is very accurate, a gaussian quadrature is usually time consuming. A closed-form is less accurate than a gaussian quadrature, but faster.

Since:

12.0

Author:

Bryan Cazabonne

Field Summary

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

DATATION_ACCURACY

Constructor Summary

Constructors

Constructor and Description
DSSTJ2SquaredClosedForm(J2SquaredModel j2SquaredModel, UnnormalizedSphericalHarmonicsProvider provider) Constructor.

Method Summary

Modifier and Type	Method and Description
<T extends org.hipparchus.CalculusFieldElement<T>> T[]	getMeanElementRate(FieldSpacecraftState<T> state, FieldAuxiliaryElements<T> auxiliaryElements, T[] parameters) Computes the mean equinoctial elements rates dai / dt.
double[]	getMeanElementRate(SpacecraftState state, 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) Performs initialization prior to propagation for the current force model.
<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 attitudeProvider) 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

Constructor Detail

DSSTJ2SquaredClosedForm

public DSSTJ2SquaredClosedForm(J2SquaredModel j2SquaredModel,
                               UnnormalizedSphericalHarmonicsProvider provider)

Constructor.

Parameters:

j2SquaredModel - model for second order terms

provider - gravity field to use

Method Detail

getMeanElementRate

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

Computes the mean equinoctial elements rates da_i / dt..

Specified by:

getMeanElementRate in interface DSSTForceModel

Parameters:

state - 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> state,
                                                                                 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:

state - 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

initializeShortPeriodTerms

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

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.

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)

getParametersDrivers

public List<ParameterDriver> getParametersDrivers()

Get the drivers for parameters..

Specified by:

getParametersDrivers in interface ParameterDriversProvider

Returns:

drivers for parameters

registerAttitudeProvider

public void registerAttitudeProvider(AttitudeProvider attitudeProvider)

Register an attitude provider.

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

.

Specified by:

registerAttitudeProvider in interface DSSTForceModel

Parameters:

attitudeProvider - the AttitudeProvider

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