Package org.orekit.propagation.events

Class FieldNodeDetector<T extends CalculusFieldElement<T>>

java.lang.Object

org.orekit.propagation.events.FieldAbstractDetector<FieldNodeDetector<T>,T>

org.orekit.propagation.events.FieldNodeDetector<T>

Type Parameters:

T - type of the field elements

All Implemented Interfaces:

FieldEventDetector<T>

public class FieldNodeDetector<T extends CalculusFieldElement<T>>
extends FieldAbstractDetector<FieldNodeDetector<T>,T>

Finder for node crossing events.

This class finds equator crossing events (i.e. ascending or descending node crossing).

The default implementation behavior is to continue propagation at descending node crossing and to stop propagation at ascending node crossing. This can be changed by calling FieldAbstractDetector.withHandler(FieldEventHandler) after construction.

Beware that node detection will fail for almost equatorial orbits. If for example a node detector is used to trigger an ImpulseManeuver and the maneuver turn the orbit plane to equator, then the detector may completely fail just after the maneuver has been performed! This is a real case that has been encountered during validation ...

Author:

Luc Maisonobe

See Also:

• FieldPropagator.addEventDetector(FieldEventDetector)

Field Summary

Fields inherited from class org.orekit.propagation.events.FieldAbstractDetector

DEFAULT_MAX_CHECK, DEFAULT_MAX_ITER, DEFAULT_THRESHOLD

Constructor Summary

Constructors

Modifier	Constructor	Description
	FieldNodeDetector(Field<T> field, Frame frame)	Build a new instance with default detection settings and stopping handler.
	FieldNodeDetector(FieldOrbit<T> orbit, Frame frame)	Build a new instance.
protected	FieldNodeDetector(FieldEventDetectionSettings<T> detectionSettings, FieldEventHandler<T> handler, Frame frame)	Constructor with detection settings and handler.
protected	FieldNodeDetector(NodeEventFunction nodeEventFunction, FieldEventDetectionSettings<T> detectionSettings, FieldEventHandler<T> handler)	Protected constructor with full parameters.
	FieldNodeDetector(T threshold, FieldOrbit<T> orbit, Frame frame)	Build a new instance.

Method Summary

Modifier and Type	Method	Description
protected FieldNodeDetector<T>	create(FieldEventDetectionSettings<T> detectionSettings, FieldEventHandler<T> newHandler)	Build a new instance.
T	g(FieldSpacecraftState<T> s)	Compute the value of the switching function.
Frame	getFrame()	Get the frame in which the equator is defined.
NodeDetector	toEventDetector(EventHandler eventHandler)	Build non-Field instance.

Methods inherited from class org.orekit.propagation.events.FieldAbstractDetector

checkIfForward, getDetectionSettings, getEventFunction, getHandler, init, isForward, withDetectionSettings, withHandler, withMaxCheck, withMaxCheck, withMaxIter, withThreshold

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.events.FieldEventDetector

finish, getMaxCheckInterval, getMaxIterationCount, getThreshold, reset

Constructor Details

FieldNodeDetector

public FieldNodeDetector(Field<T> field,
 Frame frame)

Build a new instance with default detection settings and stopping handler.

Parameters:

field - field

frame - frame in which the equator is defined (typical values are EME2000 or ITRF)

Since:

13.1.2

FieldNodeDetector

public FieldNodeDetector(FieldOrbit<T> orbit,
 Frame frame)

Build a new instance.

The orbit is used only to set an upper bound for the max check interval to period/3 and to set the convergence threshold according to orbit size.

Parameters:

orbit - initial orbit

frame - frame in which the equator is defined (typical values are EME2000 or ITRF)

FieldNodeDetector

public FieldNodeDetector(T threshold,
 FieldOrbit<T> orbit,
 Frame frame)

Build a new instance.

The orbit is used only to set an upper bound for the max check interval to period/3.

Parameters:

threshold - convergence threshold (s)

orbit - initial orbit

frame - frame in which the equator is defined (typical values are EME2000 or ITRF)

FieldNodeDetector

protected FieldNodeDetector(FieldEventDetectionSettings<T> detectionSettings,
 FieldEventHandler<T> handler,
 Frame frame)

Constructor with detection settings and handler.

Parameters:

detectionSettings - event detection settings

handler - event handler to call at event occurrences

frame - frame in which the equator is defined (typical values are EME2000 or ITRF)

Since:

13.0

FieldNodeDetector

protected FieldNodeDetector(NodeEventFunction nodeEventFunction,
 FieldEventDetectionSettings<T> detectionSettings,
 FieldEventHandler<T> handler)

Protected constructor with full parameters.

This constructor is not public as users are expected to use the builder API with the various withXxx() methods to set up the instance in a readable manner without using a huge amount of parameters.

Parameters:

nodeEventFunction - event function

detectionSettings - event detection settings

handler - event handler to call at event occurrences values are EME2000 or ITRF)

Since:

14.0

Method Details

create

protected FieldNodeDetector<T> create(FieldEventDetectionSettings<T> detectionSettings,
 FieldEventHandler<T> newHandler)

Build a new instance.

Specified by:

create in class FieldAbstractDetector<FieldNodeDetector<T extends CalculusFieldElement<T>>,T extends CalculusFieldElement<T>>

Parameters:

detectionSettings - detection settings

newHandler - event handler to call at event occurrences

Returns:

a new instance of the appropriate sub-type

getFrame

public Frame getFrame()

Get the frame in which the equator is defined.

Returns:

the frame in which the equator is defined

g

public T g(FieldSpacecraftState<T> s)

Compute the value of the switching function. This function computes the Z position in the defined frame.

Parameters:

s - the current state information: date, kinematics, attitude

Returns:

value of the switching function

toEventDetector

public NodeDetector toEventDetector(EventHandler eventHandler)

Build non-Field instance.

Overrides:

toEventDetector in class FieldAbstractDetector<FieldNodeDetector<T extends CalculusFieldElement<T>>,T extends CalculusFieldElement<T>>

Parameters:

eventHandler - event handler

Returns:

event detector