fr.cnes.sirius.patrius.propagation.analytical.multi

Class MultiAnalyticalPropagator

java.lang.Object

fr.cnes.sirius.patrius.propagation.analytical.multi.MultiAnalyticalPropagator

All Implemented Interfaces:

MultiPropagator

public class MultiAnalyticalPropagator
extends Object
implements MultiPropagator

This class is inspired from AbstractPropagator and adapted to multi propagation.

This class propagates N SpacecraftState using analytical propagators (any non-numerical propagator is accepted). Each state is identified with an ID of type String.

Multi spacecraft analytical propagation requires at least one satellite to be added to the propagator using addPropagator(Propagator, String).

The following general parameters can also be set :

• the discrete events that should be triggered during propagation (addEventDetector(EventDetector, String), clearEventsDetectors())
• the binding logic with the rest of the application (setSlaveMode(), setMasterMode(double, MultiPatriusFixedStepHandler), setMasterMode(MultiPatriusStepHandler))

Important notes:

• trying to add an instance of NumericalPropagator is forbidden but any other class based on analytical (e.g. Ephemeris) or semi-analytical (e.g. STELA) propagation is accepted, that is to say all implementations of Propagator except NumericalPropagator
• the ephemeris mode is not implemented in this propagator (not useful as of 4.14)
• the use of a MultiEventDetector is not possible through addEventDetector(MultiEventDetector), but can be used with addEventDetector(EventDetector, String) under the condition that it also implements EventDetector
• methods linked to these points throw a PatriusException with an PatriusMessages.ILLEGAL_STATE message

The same instance cannot be used simultaneously by different threads, the class is not thread-safe.

Since:

4.14

Version:

4.14

Author:

Maxime Astruc

See Also:

SpacecraftState, AbstractPropagator, MultiPatriusStepHandler, MultiPatriusFixedStepHandler

Concurrency :

not thread-safe

Concurrency comment :

attributes are mutable and related to propagation.

Field Summary

Fields inherited from interface fr.cnes.sirius.patrius.propagation.MultiPropagator

EPHEMERIS_GENERATION_MODE, MASTER_MODE, SLAVE_MODE

Constructor Summary

Constructors

Constructor and Description
MultiAnalyticalPropagator(AbsoluteDate referenceDate) Default constructor with an empty map of propagators.
MultiAnalyticalPropagator(Map<String,Propagator> analyticalPropagatorsMap, AbsoluteDate referenceDate) Constructor with an input map of propagators.

Method Summary

Modifier and Type	Method and Description
protected Map<String,SpacecraftState>	acceptStep(AbsoluteDate target, double epsilon) Accept a step, triggering events and step handlers.
void	addEventDetector(EventDetector detector, String satId) Add an event detector to a specific spacecraft.
void	addEventDetector(MultiEventDetector detector) Not authorized method: throws an unchecked exception when called.
void	addInitialState(SpacecraftState initialState, String satId) Add a new spacecraft state to be propagated.
void	addPropagator(Propagator propagator, String satId) Add an additional propagator to the map of propagators.
protected Map<String,SpacecraftState>	basicPropagate(AbsoluteDate date) Propagate an orbit without any fancy features.
void	clearEventsDetectors() Remove all events detectors.
MultiAttitudeProvider	getAttitudeProvider(String satId) Get the default attitude provider.
MultiAttitudeProvider	getAttitudeProviderEvents(String satId) Get the attitude provider for events computation.
MultiAttitudeProvider	getAttitudeProviderForces(String satId) Get the attitude provider for forces computation.
Collection<MultiEventDetector>	getEventsDetectors() Get all the events detectors that have been added.
Frame	getFrame(String satId) Get the frame in which the orbit is propagated.
BoundedPropagator	getGeneratedEphemeris(String satId) Not authorized method: throws an unchecked exception when called.
SpacecraftState	getInitialState(String satId) Get the propagator initial state of a single satellite.
Map<String,SpacecraftState>	getInitialStates() Get the propagator initial states.
int	getMode() Get the current operating mode of the propagator.
Map<String,SpacecraftStateProvider>	getPropagators() Get spacecraft state providers map.
AbsoluteDate	getReferenceDate() Get the reference date.
protected void	manageStateFrame() Manage the state frame: propagated orbits are projected in the propagation frame.
Map<String,SpacecraftState>	propagate(AbsoluteDate target) Propagate towards a target date.
Map<String,SpacecraftState>	propagate(AbsoluteDate start, AbsoluteDate target) Propagate from a start date towards a target date.
void	resetSingleInitialState(SpacecraftState newSpacecraftState, String satId) Reset the initial state of a single satellite in the initial states map.
void	setAttitudeProvider(AttitudeProvider attitudeProvider, String satId) Set attitude provider for defined spacecraft.
void	setAttitudeProviderEvents(AttitudeProvider attitudeProviderEvents, String satId) Set attitude provider for events computation.
void	setAttitudeProviderForces(AttitudeProvider attitudeProviderForces, String satId) Set attitude provider for forces computation.
void	setEphemerisMode() Not authorized method: throws an unchecked exception when called.
void	setMasterMode(double h, MultiPatriusFixedStepHandler handler) Set the propagator to master mode with fixed steps.
void	setMasterMode(MultiPatriusStepHandler handler) Set the propagator to master mode with variable steps.
void	setSlaveMode() Set the propagator to slave mode.

Methods inherited from class java.lang.Object

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

Methods inherited from interface fr.cnes.sirius.patrius.propagation.MultiPropagator

getSpacecraftState

Constructor Detail

MultiAnalyticalPropagator

public MultiAnalyticalPropagator(AbsoluteDate referenceDate)
                          throws PatriusException

Default constructor with an empty map of propagators.

Parameters:

referenceDate - date that is used as a reference to compute initial spacecraft states

Throws:

PatriusException - if a state cannot be computed or if the propagator is numerical

MultiAnalyticalPropagator

public MultiAnalyticalPropagator(Map<String,Propagator> analyticalPropagatorsMap,
                                 AbsoluteDate referenceDate)
                          throws PatriusException

Constructor with an input map of propagators. An initial state is computed for each, at propagator's input reference date.

Parameters:

analyticalPropagatorsMap - map of propagators that shall all be analytical

referenceDate - date that is used as a reference to compute initial spacecraft states

Throws:

PatriusException - if a state cannot be computed or if the propagator is numerical

Method Detail

addPropagator

public final void addPropagator(Propagator propagator,
                                String satId)
                         throws PatriusException

Add an additional propagator to the map of propagators. At each propagation step, the additional states will be retrieved and added to the map of states along with the propagated states. This allows to pass additional states to the step handler and event detectors during propagation.

Parameters:

propagator - additional propagator

satId - spacecraft ID whose state is propagated

Throws:

PatriusException - if an initial state is already defined with this ID or if the input ID is null

addInitialState

public void addInitialState(SpacecraftState initialState,
                            String satId)
                     throws PatriusException

Add a new spacecraft state to be propagated.

Specified by:

addInitialState in interface MultiPropagator

Parameters:

initialState - the new spacecraft state

satId - the spacecraft ID

Throws:

PatriusException - if an initial state is already defined with this ID. if the input ID is null. if the date of the initial state is different from the initial states already defined in the propagator.

getInitialStates

public Map<String,SpacecraftState> getInitialStates()
                                             throws PatriusException

Get the propagator initial states.

Specified by:

getInitialStates in interface MultiPropagator

Returns:

initial states

Throws:

PatriusException - if state cannot be retrieved

getInitialState

public SpacecraftState getInitialState(String satId)
                                throws PatriusException

Get the propagator initial state of a single satellite.

Parameters:

satId - ID of the satellite

Returns:

the initial state of the satellite whose ID is provided

Throws:

PatriusException - if state cannot be retrieved

getPropagators

public Map<String,SpacecraftStateProvider> getPropagators()

Get spacecraft state providers map.

Returns:

a copy of the spacecraft state providers map

getMode

public int getMode()

Get the current operating mode of the propagator.

Specified by:

getMode in interface MultiPropagator

Returns:

one of MultiPropagator.SLAVE_MODE, MultiPropagator.MASTER_MODE, MultiPropagator.EPHEMERIS_GENERATION_MODE

See Also:

MultiPropagator.setSlaveMode(), MultiPropagator.setMasterMode(double, MultiPatriusFixedStepHandler), MultiPropagator.setMasterMode(MultiPatriusStepHandler), MultiPropagator.setEphemerisMode()

setSlaveMode

public void setSlaveMode()

Set the propagator to slave mode.

This mode is used when the user needs only the final orbit at the target time. The (slave) propagator computes this result and return it to the calling (master) application, without any intermediate feedback.

This is the default mode.

Specified by:

setSlaveMode in interface MultiPropagator

See Also:

MultiPropagator.setMasterMode(double, MultiPatriusFixedStepHandler), MultiPropagator.setMasterMode(MultiPatriusStepHandler), MultiPropagator.setEphemerisMode(), MultiPropagator.getMode(), MultiPropagator.SLAVE_MODE

setMasterMode

public void setMasterMode(double h,
                          MultiPatriusFixedStepHandler handler)

Set the propagator to master mode with fixed steps.

This mode is used when the user needs to have some custom function called at the end of each finalized step during integration. The (master) propagator integration loop calls the (slave) application callback methods at each finalized step.

Specified by:

setMasterMode in interface MultiPropagator

Parameters:

h - fixed stepsize (s)

handler - handler called at the end of each finalized step

See Also:

MultiPropagator.setSlaveMode(), MultiPropagator.setMasterMode(MultiPatriusStepHandler), MultiPropagator.setEphemerisMode(), MultiPropagator.getMode(), MultiPropagator.MASTER_MODE

setMasterMode

public void setMasterMode(MultiPatriusStepHandler handler)

Set the propagator to master mode with variable steps.

This mode is used when the user needs to have some custom function called at the end of each finalized step during integration. The (master) propagator integration loop calls the (slave) application callback methods at each finalized step.

Specified by:

setMasterMode in interface MultiPropagator

Parameters:

handler - handler called at the end of each finalized step

See Also:

MultiPropagator.setSlaveMode(), MultiPropagator.setMasterMode(double, MultiPatriusFixedStepHandler), MultiPropagator.setEphemerisMode(), MultiPropagator.getMode(), MultiPropagator.MASTER_MODE

setEphemerisMode

public void setEphemerisMode()

Not authorized method: throws an unchecked exception when called.

Specified by:

setEphemerisMode in interface MultiPropagator

See Also:

MultiPropagator.getGeneratedEphemeris(String), MultiPropagator.setSlaveMode(), MultiPropagator.setMasterMode(double, MultiPatriusFixedStepHandler), MultiPropagator.setMasterMode(MultiPatriusStepHandler), MultiPropagator.getMode(), MultiPropagator.EPHEMERIS_GENERATION_MODE

getGeneratedEphemeris

public BoundedPropagator getGeneratedEphemeris(String satId)

Not authorized method: throws an unchecked exception when called.

Specified by:

getGeneratedEphemeris in interface MultiPropagator

Parameters:

satId - the spacecraft ID

Returns:

generated ephemeris

See Also:

MultiPropagator.setEphemerisMode()

addEventDetector

public void addEventDetector(MultiEventDetector detector)

Not authorized method: throws an unchecked exception when called.

Specified by:

addEventDetector in interface MultiPropagator

Parameters:

detector - event detector to add

See Also:

MultiPropagator.clearEventsDetectors(), MultiPropagator.getEventsDetectors()

addEventDetector

public void addEventDetector(EventDetector detector,
                             String satId)

Add an event detector to a specific spacecraft. The spacecraft defined by the input ID should already be added using MultiPropagator.addInitialState(SpacecraftState, String).

Specified by:

addEventDetector in interface MultiPropagator

Parameters:

detector - event detector to add

satId - the spacecraft ID

See Also:

MultiPropagator.clearEventsDetectors(), MultiPropagator.getEventsDetectors()

getEventsDetectors

public Collection<MultiEventDetector> getEventsDetectors()

Get all the events detectors that have been added.

Specified by:

getEventsDetectors in interface MultiPropagator

Returns:

an unmodifiable collection of the added detectors

See Also:

MultiPropagator.addEventDetector(MultiEventDetector), MultiPropagator.addEventDetector(EventDetector, String), MultiPropagator.clearEventsDetectors()

clearEventsDetectors

public void clearEventsDetectors()

Remove all events detectors.

Specified by:

clearEventsDetectors in interface MultiPropagator

See Also:

MultiPropagator.addEventDetector(MultiEventDetector), MultiPropagator.addEventDetector(EventDetector, String), MultiPropagator.getEventsDetectors()

getAttitudeProvider

public MultiAttitudeProvider getAttitudeProvider(String satId)

Get the default attitude provider.

The unique attitude provider given by default is returned. If null, the attitude provider for forces computation, and then the attitude provider for events computation is returned.

Warning: if you provided an AttitudeProvider then to get back your AttitudeProvider, the returned MultiAttitudeProvider should be cast to MultiAttitudeProviderWrapper and method MultiAttitudeProviderWrapper.getAttitudeProvider() should be used.

Specified by:

getAttitudeProvider in interface MultiPropagator

Parameters:

satId - the spacecraft ID

Returns:

attitude provider for forces computation (by default)

getAttitudeProviderForces

public MultiAttitudeProvider getAttitudeProviderForces(String satId)

Get the attitude provider for forces computation.

Warning: if you provided an AttitudeProvider then to get back your AttitudeProvider, the returned MultiAttitudeProvider should be cast to MultiAttitudeProviderWrapper and method MultiAttitudeProviderWrapper.getAttitudeProvider() should be used.

Specified by:

getAttitudeProviderForces in interface MultiPropagator

Parameters:

satId - the spacecraft ID

Returns:

attitude provider for forces computation, return null if not defined.

getAttitudeProviderEvents

public MultiAttitudeProvider getAttitudeProviderEvents(String satId)

Get the attitude provider for events computation.

Warning: if you provided an AttitudeProvider then to get back your AttitudeProvider, the returned MultiAttitudeProvider should be cast to MultiAttitudeProviderWrapper and method MultiAttitudeProviderWrapper.getAttitudeProvider() should be used.

Specified by:

getAttitudeProviderEvents in interface MultiPropagator

Parameters:

satId - the spacecraft ID

Returns:

attitude provider for events computation, return null if not defined.

setAttitudeProvider

public void setAttitudeProvider(AttitudeProvider attitudeProvider,
                                String satId)

Set attitude provider for defined spacecraft.

A default attitude provider is available in ConstantAttitudeLaw.

The spacecraft defined by the input ID should already be added using MultiPropagator.addInitialState(SpacecraftState, String).

Specified by:

setAttitudeProvider in interface MultiPropagator

Parameters:

attitudeProvider - attitude provider

satId - the spacecraft ID

setAttitudeProviderForces

public void setAttitudeProviderForces(AttitudeProvider attitudeProviderForces,
                                      String satId)

Set attitude provider for forces computation.

A default attitude provider is available in ConstantAttitudeLaw.

The spacecraft defined by the input ID should already be added using MultiPropagator.addInitialState(SpacecraftState, String).

Specified by:

setAttitudeProviderForces in interface MultiPropagator

Parameters:

attitudeProviderForces - attitude provider for forces computation

satId - the spacecraft ID

setAttitudeProviderEvents

public void setAttitudeProviderEvents(AttitudeProvider attitudeProviderEvents,
                                      String satId)

Set attitude provider for events computation.

A default attitude provider is available in ConstantAttitudeLaw.

The spacecraft defined by the input ID should already be added using MultiPropagator.addInitialState(SpacecraftState, String).

Specified by:

setAttitudeProviderEvents in interface MultiPropagator

Parameters:

attitudeProviderEvents - attitude provider for events computation

satId - the spacecraft ID

getFrame

public Frame getFrame(String satId)

Get the frame in which the orbit is propagated.

The propagation frame is the definition frame of the initial state, so this method should be called after this state has been set.

The spacecraft defined by the input ID should already be added using MultiPropagator.addInitialState(SpacecraftState, String).

Specified by:

getFrame in interface MultiPropagator

Parameters:

satId - the spacecraft ID

Returns:

frame in which the orbit is propagated

See Also:

MultiPropagator.addInitialState(SpacecraftState, String)

propagate

public Map<String,SpacecraftState> propagate(AbsoluteDate target)
                                      throws PropagationException

Propagate towards a target date.

Simple propagators use only the target date as the specification for computing the propagated state. More feature rich propagators can consider other information and provide different operating modes or G-stop facilities to stop at pinpointed events occurrences. In these cases, the target date is only a hint, not a mandatory objective.

Specified by:

propagate in interface MultiPropagator

Parameters:

target - target date towards which orbit state should be propagated

Returns:

propagated state

Throws:

PropagationException - if state cannot be propagated

propagate

public Map<String,SpacecraftState> propagate(AbsoluteDate start,
                                             AbsoluteDate target)
                                      throws PropagationException

Propagate from a start date towards a target date.

Those propagators use a start date and a target date to compute the propagated state. For propagators using event detection mechanism, if the provided start date is different from the initial state date, a first, simple propagation is performed, without processing any event computation. Then complete propagation is performed from start date to target date.

Specified by:

propagate in interface MultiPropagator

Parameters:

start - start date from which orbit state should be propagated

target - target date to which orbit state should be propagated

Returns:

propagated state

Throws:

PropagationException - if state cannot be propagated

basicPropagate

protected Map<String,SpacecraftState> basicPropagate(AbsoluteDate date)
                                              throws PropagationException

Propagate an orbit without any fancy features.

This method is similar in spirit to the propagate(fr.cnes.sirius.patrius.time.AbsoluteDate) method, except that it does not call any handler during propagation, nor any discrete events. It always stops exactly at the specified date.

Parameters:

date - target date for propagation

Returns:

state at specified date

Throws:

PropagationException - if propagation cannot reach specified date

acceptStep

protected Map<String,SpacecraftState> acceptStep(AbsoluteDate target,
                                                 double epsilon)
                                          throws PatriusException

Accept a step, triggering events and step handlers.

Parameters:

target - final propagation time

epsilon - threshold for end date detection

Returns:

state at the end of the step

Throws:

PatriusException - if the switching function cannot be evaluated

getReferenceDate

public AbsoluteDate getReferenceDate()

Get the reference date.

Returns:

the reference date

resetSingleInitialState

public void resetSingleInitialState(SpacecraftState newSpacecraftState,
                                    String satId)

Reset the initial state of a single satellite in the initial states map.

Parameters:

newSpacecraftState - new spacecraft state that shall be set

satId - satellite ID whose state shall be reseted

manageStateFrame

protected void manageStateFrame()
                         throws PatriusException

Manage the state frame: propagated orbits are projected in the propagation frame.

Throws:

PatriusException - if the frame of the initial state is not inertial or pseudo-inertial or if the propagator's map is empty