org.orekit.propagation.integration

Class AbstractIntegratedPropagator

java.lang.Object

org.orekit.propagation.AbstractPropagator

org.orekit.propagation.integration.AbstractIntegratedPropagator

All Implemented Interfaces:

Propagator, PVCoordinatesProvider

Direct Known Subclasses:

DSSTPropagator, NumericalPropagator

public abstract class AbstractIntegratedPropagator
extends AbstractPropagator

Common handling of Propagator methods for both numerical and semi-analytical propagators.

Author:

Luc Maisonobe

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	AbstractIntegratedPropagator.MainStateEquations Differential equations for the main state (orbit, attitude and mass).

Field Summary

Fields inherited from interface org.orekit.propagation.Propagator

DEFAULT_LAW, DEFAULT_MASS, EPHEMERIS_GENERATION_MODE, MASTER_MODE, SLAVE_MODE

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractIntegratedPropagator(AbstractIntegrator integrator) Build a new instance.

Method Summary

Methods

Modifier and Type	Method and Description
void	addAdditionalEquations(AdditionalEquations additional) Add a set of user-specified equations to be integrated along with the orbit propagation.
<T extends EventDetector> void	addEventDetector(T detector) Add an event detector.
protected void	afterIntegration() Method called just after integration.
protected void	beforeIntegration(SpacecraftState initialState, AbsoluteDate tEnd) Method called just before integration.
void	clearEventsDetectors() Remove all events detectors.
protected abstract StateMapper	createMapper(AbsoluteDate referenceDate, double mu, OrbitType orbitType, PositionAngle positionAngleType, AttitudeProvider attitudeProvider, Frame frame) Create a mapper between raw double components and spacecraft state.
int	getBasicDimension() Get state vector dimension without additional parameters.
int	getCalls() Get the number of calls to the differential equations computation method.
Collection<EventDetector>	getEventsDetectors() Get all the events detectors that have been added.
BoundedPropagator	getGeneratedEphemeris() Get the ephemeris generated during propagation.
protected abstract AbstractIntegratedPropagator.MainStateEquations	getMainStateEquations(AbstractIntegrator integ) Get the differential equations to integrate (for main state only).
String[]	getManagedAdditionalStates() Get all the names of all managed states.
double	getMu() Get the central attraction coefficient μ.
protected OrbitType	getOrbitType() Get propagation parameter type.
protected PositionAngle	getPositionAngleType() Get propagation parameter type.
protected void	initMapper() Initialize the mapper.
boolean	isAdditionalStateManaged(String name) Check if an additional state is managed.
SpacecraftState	propagate(AbsoluteDate target) Propagate towards a target date.
SpacecraftState	propagate(AbsoluteDate tStart, AbsoluteDate tEnd) Propagate from a start date towards a target date.
protected SpacecraftState	propagate(AbsoluteDate tEnd, boolean activateHandlers) Propagation with or without event detection.
void	setAttitudeProvider(AttitudeProvider attitudeProvider) Set attitude provider.
void	setEphemerisMode() Set the propagator to ephemeris generation mode.
void	setMasterMode(OrekitStepHandler handler) Set the propagator to master mode with variable steps.
void	setMu(double mu) Set the central attraction coefficient μ.
protected void	setOrbitType(OrbitType orbitType) Set propagation orbit type.
protected void	setPositionAngleType(PositionAngle positionAngleType) Set position angle type.
void	setSlaveMode() Set the propagator to slave mode.
protected <T extends EventDetector> void	setUpEventDetector(AbstractIntegrator integ, T detector) Wrap an Orekit event detector and register it to the integrator.
protected void	setUpUserEventDetectors() Set up all user defined event detectors.

Methods inherited from class org.orekit.propagation.AbstractPropagator

addAdditionalStateProvider, getAdditionalStateProviders, getAttitudeProvider, getFixedStepSize, getFrame, getInitialState, getMode, getPVCoordinates, getStartDate, getStepHandler, resetInitialState, setMasterMode, setStartDate, updateAdditionalStates

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractIntegratedPropagator

protected AbstractIntegratedPropagator(AbstractIntegrator integrator)

Build a new instance.

Parameters:

integrator - numerical integrator to use for propagation.

Method Detail

initMapper

protected void initMapper()

Initialize the mapper.

setAttitudeProvider

public void setAttitudeProvider(AttitudeProvider attitudeProvider)

Set attitude provider.

Specified by:

setAttitudeProvider in interface Propagator

Overrides:

setAttitudeProvider in class AbstractPropagator

Parameters:

attitudeProvider - attitude provider

setOrbitType

protected void setOrbitType(OrbitType orbitType)

Set propagation orbit type.

Parameters:

orbitType - orbit type to use for propagation

getOrbitType

protected OrbitType getOrbitType()

Get propagation parameter type.

Returns:

orbit type used for propagation

setPositionAngleType

protected void setPositionAngleType(PositionAngle positionAngleType)

Set position angle type.

The position parameter type is meaningful only if propagation orbit type support it. As an example, it is not meaningful for propagation in Cartesian parameters.

Parameters:

positionAngleType - angle type to use for propagation

getPositionAngleType

protected PositionAngle getPositionAngleType()

Get propagation parameter type.

Returns:

angle type to use for propagation

setMu

public void setMu(double mu)

Set the central attraction coefficient μ.

Parameters:

mu - central attraction coefficient (m³/s²)

getMu

public double getMu()

Get the central attraction coefficient μ.

Returns:

mu central attraction coefficient (m³/s²)

See Also:

setMu(double)

getCalls

public int getCalls()

Get the number of calls to the differential equations computation method.

The number of calls is reset each time the propagate(AbsoluteDate) method is called.

Returns:

number of calls to the differential equations computation method

isAdditionalStateManaged

public boolean isAdditionalStateManaged(String name)

Check if an additional state is managed.

Managed states are states for which the propagators know how to compute its evolution. They correspond to additional states for which an additional state provider has been registered by calling the addAdditionalStateProvider method. If the propagator is an integrator-based propagator, the states for which a set of additional equations has been registered by calling the addAdditionalEquations method are also counted as managed additional states.

Additional states that are present in the initial state but have no evolution method registered are not considered as managed states. These unmanaged additional states are not lost during propagation, though. Their value will simply be copied unchanged throughout propagation.

Specified by:

isAdditionalStateManaged in interface Propagator

Overrides:

isAdditionalStateManaged in class AbstractPropagator

Parameters:

name - name of the additional state

Returns:

true if the additional state is managed

getManagedAdditionalStates

public String[] getManagedAdditionalStates()

Get all the names of all managed states.

Specified by:

getManagedAdditionalStates in interface Propagator

Overrides:

getManagedAdditionalStates in class AbstractPropagator

Returns:

names of all managed states

addAdditionalEquations

public void addAdditionalEquations(AdditionalEquations additional)
                            throws OrekitException

Add a set of user-specified equations to be integrated along with the orbit propagation.

Parameters:

additional - additional equations

Throws:

OrekitException - if a set of equations with the same name is already present

addEventDetector

public <T extends EventDetector> void addEventDetector(T detector)

Add an event detector.

Specified by:

addEventDetector in interface Propagator

Specified by:

addEventDetector in class AbstractPropagator

Type Parameters:

T - class type for the generic version

Parameters:

detector - event detector to add

See Also:

Propagator.clearEventsDetectors(), Propagator.getEventsDetectors()

getEventsDetectors

public Collection<EventDetector> getEventsDetectors()

Get all the events detectors that have been added.

Specified by:

getEventsDetectors in interface Propagator

Specified by:

getEventsDetectors in class AbstractPropagator

Returns:

an unmodifiable collection of the added detectors

See Also:

Propagator.addEventDetector(EventDetector), Propagator.clearEventsDetectors()

clearEventsDetectors

public void clearEventsDetectors()

Remove all events detectors.

Specified by:

clearEventsDetectors in interface Propagator

Specified by:

clearEventsDetectors in class AbstractPropagator

See Also:

Propagator.addEventDetector(EventDetector), Propagator.getEventsDetectors()

setUpUserEventDetectors

protected void setUpUserEventDetectors()

Set up all user defined event detectors.

setUpEventDetector

protected <T extends EventDetector> void setUpEventDetector(AbstractIntegrator integ,
                                                T detector)

Wrap an Orekit event detector and register it to the integrator.

Type Parameters:

T - class type for the generic version

Parameters:

integ - integrator into which event detector should be registered

detector - event detector to wrap

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.

Note that this method has the side effect of replacing the step handlers of the underlying integrator set up in the constructor. So if a specific step handler is needed, it should be added after this method has been callled.

Specified by:

setSlaveMode in interface Propagator

Overrides:

setSlaveMode in class AbstractPropagator

See Also:

Propagator.setMasterMode(double, OrekitFixedStepHandler), Propagator.setMasterMode(OrekitStepHandler), Propagator.setEphemerisMode(), Propagator.getMode(), Propagator.SLAVE_MODE

setMasterMode

public void setMasterMode(OrekitStepHandler 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.

Note that this method has the side effect of replacing the step handlers of the underlying integrator set up in the constructor. So if a specific step handler is needed, it should be added after this method has been callled.

Specified by:

setMasterMode in interface Propagator

Overrides:

setMasterMode in class AbstractPropagator

Parameters:

handler - handler called at the end of each finalized step

See Also:

Propagator.setSlaveMode(), Propagator.setMasterMode(double, OrekitFixedStepHandler), Propagator.setEphemerisMode(), Propagator.getMode(), Propagator.MASTER_MODE

setEphemerisMode

public void setEphemerisMode()

Set the propagator to ephemeris generation mode.

This mode is used when the user needs random access to the orbit state at any time between the initial and target times, and in no sequential order. A typical example is the implementation of search and iterative algorithms that may navigate forward and backward inside the propagation range before finding their result.

Beware that since this mode stores all intermediate results, it may be memory intensive for long integration ranges and high precision/short time steps.

Note that this method has the side effect of replacing the step handlers of the underlying integrator set up in the constructor. So if a specific step handler is needed, it should be added after this method has been called.

Specified by:

setEphemerisMode in interface Propagator

Overrides:

setEphemerisMode in class AbstractPropagator

See Also:

Propagator.getGeneratedEphemeris(), Propagator.setSlaveMode(), Propagator.setMasterMode(double, OrekitFixedStepHandler), Propagator.setMasterMode(OrekitStepHandler), Propagator.getMode(), Propagator.EPHEMERIS_GENERATION_MODE

getGeneratedEphemeris

public BoundedPropagator getGeneratedEphemeris()
                                        throws IllegalStateException

Get the ephemeris generated during propagation.

Specified by:

getGeneratedEphemeris in interface Propagator

Specified by:

getGeneratedEphemeris in class AbstractPropagator

Returns:

generated ephemeris

Throws:

IllegalStateException - if the propagator was not set in ephemeris generation mode before propagation

See Also:

Propagator.setEphemerisMode()

createMapper

protected abstract StateMapper createMapper(AbsoluteDate referenceDate,
                       double mu,
                       OrbitType orbitType,
                       PositionAngle positionAngleType,
                       AttitudeProvider attitudeProvider,
                       Frame frame)

Create a mapper between raw double components and spacecraft state. /** Simple constructor.

The position parameter type is meaningful only if propagation orbit type support it. As an example, it is not meaningful for propagation in Cartesian parameters.

Parameters:

referenceDate - reference date

mu - central attraction coefficient (m³/s²)

orbitType - orbit type to use for mapping

positionAngleType - angle type to use for propagation

attitudeProvider - attitude provider

frame - inertial frame

Returns:

new mapper

getMainStateEquations

protected abstract AbstractIntegratedPropagator.MainStateEquations getMainStateEquations(AbstractIntegrator integ)

Get the differential equations to integrate (for main state only).

Parameters:

integ - numerical integrator to use for propagation.

Returns:

differential equations for main state

propagate

public 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 Propagator

Overrides:

propagate in class AbstractPropagator

Parameters:

target - target date towards which orbit state should be propagated

Returns:

propagated state

Throws:

PropagationException - if state cannot be propagated

propagate

public SpacecraftState propagate(AbsoluteDate tStart,
                        AbsoluteDate tEnd)
                          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.

Parameters:

tStart - start date from which orbit state should be propagated

tEnd - target date to which orbit state should be propagated

Returns:

propagated state

Throws:

PropagationException - if state cannot be propagated

propagate

protected SpacecraftState propagate(AbsoluteDate tEnd,
                        boolean activateHandlers)
                             throws PropagationException

Propagation with or without event detection.

Parameters:

tEnd - target date to which orbit should be propagated

activateHandlers - if true, step and event handlers should be activated

Returns:

state at end of propagation

Throws:

PropagationException - if orbit cannot be propagated

beforeIntegration

protected void beforeIntegration(SpacecraftState initialState,
                     AbsoluteDate tEnd)
                          throws OrekitException

Method called just before integration.

The default implementation does nothing, it may be specialized in subclasses.

Parameters:

initialState - initial state

tEnd - target date at which state should be propagated

Throws:

OrekitException - if hook cannot be run

afterIntegration

protected void afterIntegration()
                         throws OrekitException

Method called just after integration.

The default implementation does nothing, it may be specialized in subclasses.

Throws:

OrekitException - if hook cannot be run

getBasicDimension

public int getBasicDimension()

Get state vector dimension without additional parameters.

Returns:

state vector dimension without additional parameters.