org.orekit.propagation.semianalytical.dsst.forces

Interface DSSTForceModel

All Known Implementing Classes:

AbstractGaussianContribution, DSSTAtmosphericDrag, DSSTNewtonianAttraction, DSSTSolarRadiationPressure, DSSTTesseral, DSSTThirdBody, DSSTZonal

public interface DSSTForceModel

This interface represents a force modifying spacecraft motion for a DSSTPropagator.

Objects implementing this interface are intended to be added to a DSST propagator before the propagation is started.

The propagator will call at the very beginning of a propagation the initializeShortPeriodTerms(AuxiliaryElements, PropagationType, double[]) method allowing preliminary computation such as truncation if needed.

Then the propagator will call at each step:

1. the getMeanElementRate(SpacecraftState, AuxiliaryElements, double[]) method. The force model instance will extract all the state data needed to compute the mean element rates that contribute to the mean state derivative.
2. the updateShortPeriodTerms(double[], SpacecraftState...) method, if osculating parameters are desired, on a sample of points within the last step.

Author:

Romain Di Constanzo, Pascal Parraud

Method Summary

Modifier and Type	Method and Description
EventDetector[]	getEventsDetectors() Get the discrete events related to the model.
<T extends CalculusFieldElement<T>> FieldEventDetector<T>[]	getFieldEventsDetectors(Field<T> field) Get the discrete events related to the model.
<T extends 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.
default double[]	getParameters() Get force model parameters.
default <T extends CalculusFieldElement<T>> T[]	getParameters(Field<T> field) Get force model parameters.
List<ParameterDriver>	getParametersDrivers() Get the drivers for force model parameters.
default <T extends CalculusFieldElement<T>> void	init(FieldSpacecraftState<T> initialState, FieldAbsoluteDate<T> target) Initialize the force model at the start of propagation.
default void	init(SpacecraftState initialState, AbsoluteDate target) Initialize the force model at the start of propagation.
List<ShortPeriodTerms>	initializeShortPeriodTerms(AuxiliaryElements auxiliaryElements, PropagationType type, double[] parameters) Performs initialization prior to propagation for the current force model.
<T extends 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 CalculusFieldElement<T>> void	updateShortPeriodTerms(T[] parameters, FieldSpacecraftState<T>... meanStates) Update the short period terms.

Method Detail

init

default void init(SpacecraftState initialState,
                  AbsoluteDate target)

Initialize the force model at the start of propagation.

The default implementation of this method does nothing.

Parameters:

initialState - spacecraft state at the start of propagation.

target - date of propagation. Not equal to initialState.getDate().

Since:

11.0

init

default <T extends CalculusFieldElement<T>> void init(FieldSpacecraftState<T> initialState,
                                                      FieldAbsoluteDate<T> target)

Initialize the force model at the start of propagation.

The default implementation of this method does nothing.

Type Parameters:

T - type of the elements

Parameters:

initialState - spacecraft state at the start of propagation.

target - date of propagation. Not equal to initialState.getDate().

Since:

11.1

initializeShortPeriodTerms

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.

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

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

<T extends 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.

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

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)

getParameters

default double[] getParameters()

Get force model parameters.

Returns:

force model parameters

Since:

9.0

getParameters

default <T extends CalculusFieldElement<T>> T[] getParameters(Field<T> field)

Get force model parameters.

Type Parameters:

T - type of the elements

Parameters:

field - field to which the elements belong

Returns:

force model parameters

Since:

9.0

getMeanElementRate

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

Computes the mean equinoctial elements rates da_i / dt.

Parameters:

state - current state information: date, kinematics, attitude

auxiliaryElements - auxiliary elements related to the current orbit

parameters - values of the force model parameters

Returns:

the mean element rates dai/dt

getMeanElementRate

<T extends CalculusFieldElement<T>> T[] getMeanElementRate(FieldSpacecraftState<T> state,
                                                           FieldAuxiliaryElements<T> auxiliaryElements,
                                                           T[] parameters)

Computes the mean equinoctial elements rates da_i / dt.

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

Returns:

the mean element rates dai/dt

getEventsDetectors

EventDetector[] getEventsDetectors()

Get the discrete events related to the model.

Returns:

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

getFieldEventsDetectors

<T extends CalculusFieldElement<T>> FieldEventDetector<T>[] getFieldEventsDetectors(Field<T> field)

Get the discrete events related to the model.

Type Parameters:

T - type of the elements

Parameters:

field - field used by default

Returns:

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

registerAttitudeProvider

void registerAttitudeProvider(AttitudeProvider provider)

Register an attitude provider.

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

Parameters:

provider - the AttitudeProvider

updateShortPeriodTerms

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 initializeShortPeriodTerms(AuxiliaryElements, PropagationType, double[]).

Parameters:

parameters - values of the force model parameters

meanStates - mean states information: date, kinematics, attitude

updateShortPeriodTerms

<T extends 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 initializeShortPeriodTerms(AuxiliaryElements, PropagationType, double[]).

Type Parameters:

T - type of the elements

Parameters:

parameters - values of the force model parameters

meanStates - mean states information: date, kinematics, attitude

getParametersDrivers

List<ParameterDriver> getParametersDrivers()

Get the drivers for force model parameters.

Returns:

drivers for force model parameters