org.orekit.propagation.integration

Class FieldAbstractIntegratedPropagator<T extends CalculusFieldElement<T>>

java.lang.Object

org.orekit.propagation.FieldAbstractPropagator<T>

org.orekit.propagation.integration.FieldAbstractIntegratedPropagator<T>

Type Parameters:

T - the type of the field elements

All Implemented Interfaces:

FieldPropagator<T>, FieldPVCoordinatesProvider<T>

Direct Known Subclasses:

FieldDSSTPropagator, FieldNumericalPropagator

public abstract class FieldAbstractIntegratedPropagator<T extends CalculusFieldElement<T>>
extends FieldAbstractPropagator<T>

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

Author:

Luc Maisonobe

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	FieldAbstractIntegratedPropagator.MainStateEquations<T extends CalculusFieldElement<T>> Differential equations for the main state (orbit, attitude and mass).

Field Summary

Fields inherited from interface org.orekit.propagation.FieldPropagator

DEFAULT_MASS

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	FieldAbstractIntegratedPropagator(Field<T> field, FieldODEIntegrator<T> integrator, PropagationType propagationType) Build a new instance.

Method Summary

Modifier and Type	Method and Description
void	addAdditionalEquations(FieldAdditionalEquations<T> additional) Add a set of user-specified equations to be integrated along with the orbit propagation.
<D extends FieldEventDetector<T>> void	addEventDetector(D detector) Add an event detector.
protected void	afterIntegration() Method called just after integration.
protected void	beforeIntegration(FieldSpacecraftState<T> initialState, FieldAbsoluteDate<T> tEnd) Method called just before integration.
void	clearEventsDetectors() Remove all events detectors.
protected abstract FieldStateMapper<T>	createMapper(FieldAbsoluteDate<T> referenceDate, T 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.
FieldEphemerisGenerator<T>	getEphemerisGenerator() Set up an ephemeris generator that will monitor the propagation for building an ephemeris from it once completed.
Collection<FieldEventDetector<T>>	getEventsDetectors() Get all the events detectors that have been added.
protected FieldSpacecraftState<T>	getInitialIntegrationState() Get the initial state for integration.
protected FieldODEIntegrator<T>	getIntegrator() Get the integrator used by the propagator.
protected abstract FieldAbstractIntegratedPropagator.MainStateEquations<T>	getMainStateEquations(FieldODEIntegrator<T> integ) Get the differential equations to integrate (for main state only).
String[]	getManagedAdditionalStates() Get all the names of all managed states.
T	getMu() Get the central attraction coefficient μ.
protected OrbitType	getOrbitType() Get propagation parameter type.
protected PositionAngle	getPositionAngleType() Get propagation parameter type.
protected void	initMapper(Field<T> field) Initialize the mapper.
boolean	isAdditionalStateManaged(String name) Check if an additional state is managed.
protected PropagationType	isMeanOrbit() Check if only the mean elements should be used in a semianalitical propagation.
FieldSpacecraftState<T>	propagate(FieldAbsoluteDate<T> target) Propagate towards a target date.
FieldSpacecraftState<T>	propagate(FieldAbsoluteDate<T> tStart, FieldAbsoluteDate<T> tEnd) Propagate from a start date towards a target date.
void	setAttitudeProvider(AttitudeProvider attitudeProvider) Set attitude provider.
void	setMu(T 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	setResetAtEnd(boolean resetAtEnd) Allow/disallow resetting the initial state at end of propagation.
protected void	setUpEventDetector(FieldODEIntegrator<T> integ, FieldEventDetector<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.FieldAbstractPropagator

addAdditionalStateProvider, getAdditionalStateProviders, getAttitudeProvider, getField, getFrame, getInitialState, getMultiplexer, getPVCoordinates, getStartDate, initializePropagation, resetInitialState, setStartDate, stateChanged, updateAdditionalStates

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

clearStepHandlers, setStepHandler, setStepHandler

Constructor Detail

FieldAbstractIntegratedPropagator

protected FieldAbstractIntegratedPropagator(Field<T> field,
                                            FieldODEIntegrator<T> integrator,
                                            PropagationType propagationType)

Build a new instance.

Parameters:

integrator - numerical integrator to use for propagation.

propagationType - type of orbit to output (mean or osculating).

field - Field used by default

Method Detail

setResetAtEnd

public void setResetAtEnd(boolean resetAtEnd)

Allow/disallow resetting the initial state at end of propagation.

By default, at the end of the propagation, the propagator resets the initial state to the final state, thus allowing a new propagation to be started from there without recomputing the part already performed. Calling this method with resetAtEnd set to false changes prevents such reset.

Parameters:

resetAtEnd - if true, at end of each propagation, the initial state will be reset to the final state of the propagation, otherwise the initial state will be preserved

Since:

9.0

initMapper

protected void initMapper(Field<T> field)

Initialize the mapper.

Parameters:

field - Field used by default

setAttitudeProvider

public void setAttitudeProvider(AttitudeProvider attitudeProvider)

Set attitude provider.

Specified by:

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

Overrides:

setAttitudeProvider in class FieldAbstractPropagator<T extends CalculusFieldElement<T>>

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

isMeanOrbit

protected PropagationType isMeanOrbit()

Check if only the mean elements should be used in a semianalitical propagation.

Returns:

MEAN if only mean elements have to be used or OSCULATING if osculating elements have to be also used.

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(T mu)

Set the central attraction coefficient μ.

Parameters:

mu - central attraction coefficient (m³/s²)

getMu

public T getMu()

Get the central attraction coefficient μ.

Returns:

mu central attraction coefficient (m³/s²)

See Also:

setMu(CalculusFieldElement)

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(FieldAbsoluteDate) 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 are piecewise constant between state resets that may change them if some event handler resetState method is called at an event occurrence and happens to change the unmanaged additional state.

Specified by:

isAdditionalStateManaged in interface FieldPropagator<T extends CalculusFieldElement<T>>

Overrides:

isAdditionalStateManaged in class FieldAbstractPropagator<T extends CalculusFieldElement<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 CalculusFieldElement<T>>

Overrides:

getManagedAdditionalStates in class FieldAbstractPropagator<T extends CalculusFieldElement<T>>

Returns:

names of all managed states

addAdditionalEquations

public void addAdditionalEquations(FieldAdditionalEquations<T> additional)

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

Parameters:

additional - additional equations

addEventDetector

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

Add an event detector.

Type Parameters:

D - class type for the generic version

Parameters:

detector - event detector to add

See Also:

FieldPropagator.clearEventsDetectors(), FieldPropagator.getEventsDetectors()

getEventsDetectors

public Collection<FieldEventDetector<T>> getEventsDetectors()

Get all the events detectors that have been added.

Returns:

an unmodifiable collection of the added detectors

See Also:

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

clearEventsDetectors

public void clearEventsDetectors()

Remove all events detectors.

See Also:

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

setUpUserEventDetectors

protected void setUpUserEventDetectors()

Set up all user defined event detectors.

setUpEventDetector

protected void setUpEventDetector(FieldODEIntegrator<T> integ,
                                  FieldEventDetector<T> detector)

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

Parameters:

integ - integrator into which event detector should be registered

detector - event detector to wrap

getEphemerisGenerator

public FieldEphemerisGenerator<T> getEphemerisGenerator()

Set up an ephemeris generator that will monitor the propagation for building an ephemeris from it once completed.

This generator can be used when the user needs fast random access to the orbit state at any time between the initial and target times. 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 even if the propagator used is integration-based and only goes from one initial time to one target time.

Beware that when used with integration-based propagators, the generator will store all intermediate results. It is therefore memory intensive for long integration-based ranges and high precision/short time steps. When used with analytical propagators, the generator only stores start/stop time and a reference to the analytical propagator itself to call it back as needed, so it is less memory intensive.

The returned ephemeris generator will be initially empty, it will be filled with propagation data when a subsequent call to either propagate(target) or propagate(start, target) is called. The proper way to use this method is therefore to do:

   FieldEphemerisGenerator<T> generator = propagator.getEphemerisGenerator();
   propagator.propagate(target);
   FieldBoundedPropagator<T> ephemeris = generator.getGeneratedEphemeris();
 

Returns:

ephemeris generator

createMapper

protected abstract FieldStateMapper<T> createMapper(FieldAbsoluteDate<T> referenceDate,
                                                    T 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 FieldAbstractIntegratedPropagator.MainStateEquations<T> getMainStateEquations(FieldODEIntegrator<T> 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 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 CalculusFieldElement<T>>

Overrides:

propagate in class FieldAbstractPropagator<T extends CalculusFieldElement<T>>

Parameters:

target - target date towards which orbit state should be propagated

Returns:

propagated state

propagate

public FieldSpacecraftState<T> propagate(FieldAbsoluteDate<T> tStart,
                                         FieldAbsoluteDate<T> tEnd)

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

getInitialIntegrationState

protected FieldSpacecraftState<T> getInitialIntegrationState()

Get the initial state for integration.

Returns:

initial state for integration

beforeIntegration

protected void beforeIntegration(FieldSpacecraftState<T> initialState,
                                 FieldAbsoluteDate<T> tEnd)

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

afterIntegration

protected void afterIntegration()

Method called just after integration.

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

getBasicDimension

public int getBasicDimension()

Get state vector dimension without additional parameters.

Returns:

state vector dimension without additional parameters.

getIntegrator

protected FieldODEIntegrator<T> getIntegrator()

Get the integrator used by the propagator.

Returns:

the integrator.