org.orekit.propagation

Class FieldAbstractPropagator<T extends RealFieldElement<T>>

java.lang.Object

org.orekit.propagation.FieldAbstractPropagator<T>

All Implemented Interfaces:

FieldPropagator<T>, FieldPVCoordinatesProvider<T>

Direct Known Subclasses:

FieldAbstractAnalyticalPropagator, FieldAbstractIntegratedPropagator

public abstract class FieldAbstractPropagator<T extends RealFieldElement<T>>
extends Object
implements FieldPropagator<T>

Common handling of Propagator methods for analytical propagators.

This abstract class allows to provide easily the full set of Propagator methods, including all propagation modes support and discrete events support for any simple propagation method.

Author:

Luc Maisonobe

Field Summary

Fields inherited from interface org.orekit.propagation.FieldPropagator

DEFAULT_LAW, DEFAULT_MASS, EPHEMERIS_GENERATION_MODE, MASTER_MODE, SLAVE_MODE

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	FieldAbstractPropagator(Field<T> field) Build a new instance.

Method Summary

Modifier and Type	Method and Description
void	addAdditionalStateProvider(FieldAdditionalStateProvider<T> additionalStateProvider) Add a set of user-specified state parameters to be computed along with the orbit propagation.
abstract <D extends FieldEventDetector<T>> void	addEventDetector(D detector) Add an event detector.
abstract void	clearEventsDetectors() Remove all events detectors.
List<FieldAdditionalStateProvider<T>>	getAdditionalStateProviders() Get an unmodifiable list of providers for additional state.
AttitudeProvider	getAttitudeProvider() Get attitude provider.
abstract Collection<FieldEventDetector<T>>	getEventsDetectors() Get all the events detectors that have been added.
Field<T>	getField() Field getter.
protected T	getFixedStepSize() Get the fixed step size.
Frame	getFrame() Get the frame in which the orbit is propagated.
abstract FieldBoundedPropagator<T>	getGeneratedEphemeris() Get the ephemeris generated during propagation.
FieldSpacecraftState<T>	getInitialState() Get the propagator initial state.
String[]	getManagedAdditionalStates() Get all the names of all managed states.
int	getMode() Get the current operating mode of the propagator.
TimeStampedFieldPVCoordinates<T>	getPVCoordinates(FieldAbsoluteDate<T> date, Frame frame) Get the FieldPVCoordinates of the body in the selected frame.
protected FieldAbsoluteDate<T>	getStartDate() Get the start date.
protected FieldOrekitStepHandler<T>	getStepHandler() Get the step handler.
boolean	isAdditionalStateManaged(String name) Check if an additional state is managed.
FieldSpacecraftState<T>	propagate(FieldAbsoluteDate<T> target) Propagate towards a target date.
void	resetInitialState(FieldSpacecraftState<T> state) Reset the propagator initial state.
void	setAttitudeProvider(AttitudeProvider attitudeProvider) Set attitude provider.
void	setEphemerisMode() Set the propagator to ephemeris generation mode.
void	setMasterMode(FieldOrekitStepHandler<T> handler) Set the propagator to master mode with variable steps.
void	setMasterMode(T h, FieldOrekitFixedStepHandler<T> handler) Set the propagator to master mode with fixed steps.
void	setSlaveMode() Set the propagator to slave mode.
protected void	setStartDate(FieldAbsoluteDate<T> startDate) Set a start date.
protected FieldSpacecraftState<T>	updateAdditionalStates(FieldSpacecraftState<T> original) Update state by adding all additional states.

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.FieldPropagator

propagate

Constructor Detail

FieldAbstractPropagator

protected FieldAbstractPropagator(Field<T> field)

Build a new instance.

Parameters:

field - setting the field

Method Detail

setStartDate

protected void setStartDate(FieldAbsoluteDate<T> startDate)

Set a start date.

Parameters:

startDate - start date

getStartDate

protected FieldAbsoluteDate<T> getStartDate()

Get the start date.

Returns:

start date

getAttitudeProvider

public AttitudeProvider getAttitudeProvider()

Get attitude provider.

Specified by:

getAttitudeProvider in interface FieldPropagator<T extends RealFieldElement<T>>

Returns:

attitude provider

setAttitudeProvider

public void setAttitudeProvider(AttitudeProvider attitudeProvider)

Set attitude provider.

Specified by:

setAttitudeProvider in interface FieldPropagator<T extends RealFieldElement<T>>

Parameters:

attitudeProvider - attitude provider

getField

public Field<T> getField()

Field getter.

Returns:

field used

getInitialState

public FieldSpacecraftState<T> getInitialState()

Get the propagator initial state.

Specified by:

getInitialState in interface FieldPropagator<T extends RealFieldElement<T>>

Returns:

initial state

getMode

public int getMode()

Get the current operating mode of the propagator.

Specified by:

getMode in interface FieldPropagator<T extends RealFieldElement<T>>

Returns:

one of FieldPropagator.SLAVE_MODE, FieldPropagator.MASTER_MODE, FieldPropagator.EPHEMERIS_GENERATION_MODE

See Also:

FieldPropagator.setSlaveMode(), FieldPropagator.setMasterMode(RealFieldElement, FieldOrekitFixedStepHandler), FieldPropagator.setMasterMode(FieldOrekitStepHandler), FieldPropagator.setEphemerisMode()

getFrame

public Frame getFrame()

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, otherwise it may return null.

Specified by:

getFrame in interface FieldPropagator<T extends RealFieldElement<T>>

Returns:

frame in which the orbit is propagated

See Also:

FieldPropagator.resetInitialState(FieldSpacecraftState)

resetInitialState

public void resetInitialState(FieldSpacecraftState<T> state)

Reset the propagator initial state.

Specified by:

resetInitialState in interface FieldPropagator<T extends RealFieldElement<T>>

Parameters:

state - new initial state to consider

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 FieldPropagator<T extends RealFieldElement<T>>

See Also:

FieldPropagator.setMasterMode(RealFieldElement, FieldOrekitFixedStepHandler), FieldPropagator.setMasterMode(FieldOrekitStepHandler), FieldPropagator.setEphemerisMode(), FieldPropagator.getMode(), FieldPropagator.SLAVE_MODE

setMasterMode

public void setMasterMode(T h,
                          FieldOrekitFixedStepHandler<T> 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 FieldPropagator<T extends RealFieldElement<T>>

Parameters:

h - fixed stepsize (s)

handler - handler called at the end of each finalized step

See Also:

FieldPropagator.setSlaveMode(), FieldPropagator.setMasterMode(FieldOrekitStepHandler), FieldPropagator.setEphemerisMode(), FieldPropagator.getMode(), FieldPropagator.MASTER_MODE

setMasterMode

public void setMasterMode(FieldOrekitStepHandler<T> 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 FieldPropagator<T extends RealFieldElement<T>>

Parameters:

handler - handler called at the end of each finalized step

See Also:

FieldPropagator.setSlaveMode(), FieldPropagator.setMasterMode(RealFieldElement, FieldOrekitFixedStepHandler), FieldPropagator.setEphemerisMode(), FieldPropagator.getMode(), FieldPropagator.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.

Specified by:

setEphemerisMode in interface FieldPropagator<T extends RealFieldElement<T>>

See Also:

FieldPropagator.getGeneratedEphemeris(), FieldPropagator.setSlaveMode(), FieldPropagator.setMasterMode(RealFieldElement, FieldOrekitFixedStepHandler), FieldPropagator.setMasterMode(FieldOrekitStepHandler), FieldPropagator.getMode(), FieldPropagator.EPHEMERIS_GENERATION_MODE

addAdditionalStateProvider

public void addAdditionalStateProvider(FieldAdditionalStateProvider<T> additionalStateProvider)

Add a set of user-specified state parameters to be computed along with the orbit propagation.

Specified by:

addAdditionalStateProvider in interface FieldPropagator<T extends RealFieldElement<T>>

Parameters:

additionalStateProvider - provider for additional state

getAdditionalStateProviders

public List<FieldAdditionalStateProvider<T>> getAdditionalStateProviders()

Get an unmodifiable list of providers for additional state.

Specified by:

getAdditionalStateProviders in interface FieldPropagator<T extends RealFieldElement<T>>

Returns:

providers for the additional states

updateAdditionalStates

protected FieldSpacecraftState<T> updateAdditionalStates(FieldSpacecraftState<T> original)

Update state by adding all additional states.

Parameters:

original - original state

Returns:

updated state, with all additional states included

See Also:

addAdditionalStateProvider(FieldAdditionalStateProvider)

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 FieldPropagator<T extends RealFieldElement<T>>

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 FieldPropagator<T extends RealFieldElement<T>>

Returns:

names of all managed states

getFixedStepSize

protected T getFixedStepSize()

Get the fixed step size.

Returns:

fixed step size (or NaN if there are no fixed step size).

getStepHandler

protected FieldOrekitStepHandler<T> getStepHandler()

Get the step handler.

Returns:

step handler

getGeneratedEphemeris

public abstract FieldBoundedPropagator<T> getGeneratedEphemeris()

Get the ephemeris generated during propagation.

Specified by:

getGeneratedEphemeris in interface FieldPropagator<T extends RealFieldElement<T>>

Returns:

generated ephemeris

See Also:

FieldPropagator.setEphemerisMode()

addEventDetector

public abstract <D extends FieldEventDetector<T>> void addEventDetector(D detector)

Add an event detector.

Specified by:

addEventDetector in interface FieldPropagator<T extends RealFieldElement<T>>

Type Parameters:

D - class type for the generic version

Parameters:

detector - event detector to add

See Also:

FieldPropagator.clearEventsDetectors(), FieldPropagator.getEventsDetectors()

getEventsDetectors

public abstract Collection<FieldEventDetector<T>> getEventsDetectors()

Get all the events detectors that have been added.

Specified by:

getEventsDetectors in interface FieldPropagator<T extends RealFieldElement<T>>

Returns:

an unmodifiable collection of the added detectors

See Also:

FieldPropagator.addEventDetector(FieldEventDetector), FieldPropagator.clearEventsDetectors()

clearEventsDetectors

public abstract void clearEventsDetectors()

Remove all events detectors.

Specified by:

clearEventsDetectors in interface FieldPropagator<T extends RealFieldElement<T>>

See Also:

FieldPropagator.addEventDetector(FieldEventDetector), FieldPropagator.getEventsDetectors()

propagate

public FieldSpacecraftState<T> propagate(FieldAbsoluteDate<T> target)

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 FieldPropagator<T extends RealFieldElement<T>>

Parameters:

target - target date towards which orbit state should be propagated

Returns:

propagated state

getPVCoordinates

public TimeStampedFieldPVCoordinates<T> getPVCoordinates(FieldAbsoluteDate<T> date,
                                                         Frame frame)

Get the FieldPVCoordinates of the body in the selected frame.

Specified by:

getPVCoordinates in interface FieldPVCoordinatesProvider<T extends RealFieldElement<T>>

Parameters:

date - current date

frame - the frame where to define the position

Returns:

time-stamped position/velocity of the body (m and m/s)