org.orekit.propagation.events

Class FieldApsideDetector<T extends org.hipparchus.RealFieldElement<T>>

java.lang.Object

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

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

All Implemented Interfaces:

FieldEventDetector<T>

public class FieldApsideDetector<T extends org.hipparchus.RealFieldElement<T>>
extends FieldAbstractDetector<FieldApsideDetector<T>,T>

Finder for apside crossing events.

This class finds apside crossing events (i.e. apogee or perigee crossing).

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

Beware that apside detection will fail for almost circular orbits. If for example an apside detector is used to trigger an ImpulseManeuver and the maneuver change the orbit shape to circular, then the detector may completely fail just after the maneuver has been performed!

Author:

Luc Maisonobe

See Also:

FieldPropagator.addEventDetector(FieldEventDetector)

Field Summary

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

DEFAULT_MAX_ITER, DEFAULT_MAXCHECK, DEFAULT_THRESHOLD

Constructor Summary

Constructors

Constructor and Description
FieldApsideDetector(FieldOrbit<T> orbit) Build a new instance.
FieldApsideDetector(T threshold, FieldOrbit<T> orbit) Build a new instance.

Method Summary

Modifier and Type	Method and Description
protected FieldApsideDetector<T>	create(T newMaxCheck, T newThreshold, int newMaxIter, FieldEventHandler<? super FieldApsideDetector<T>,T> newHandler) Build a new instance.
T	g(FieldSpacecraftState<T> s) Compute the value of the switching function.

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

eventOccurred, getHandler, getMaxCheckInterval, getMaxIterationCount, getThreshold, init, isForward, resetState, withHandler, withMaxCheck, withMaxIter, withThreshold

Methods inherited from class java.lang.Object

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

Constructor Detail

FieldApsideDetector

public FieldApsideDetector(FieldOrbit<T> orbit)

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

FieldApsideDetector

public FieldApsideDetector(T threshold,
                           FieldOrbit<T> orbit)

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

Method Detail

create

protected FieldApsideDetector<T> create(T newMaxCheck,
                                        T newThreshold,
                                        int newMaxIter,
                                        FieldEventHandler<? super FieldApsideDetector<T>,T> newHandler)

Build a new instance.

Specified by:

create in class FieldAbstractDetector<FieldApsideDetector<T extends org.hipparchus.RealFieldElement<T>>,T extends org.hipparchus.RealFieldElement<T>>

Parameters:

newMaxCheck - maximum checking interval (s)

newThreshold - convergence threshold (s)

newMaxIter - maximum number of iterations in the event time search

newHandler - event handler to call at event occurrences

Returns:

a new instance of the appropriate sub-type

g

public T g(FieldSpacecraftState<T> s)
    throws OrekitException

Compute the value of the switching function. This function computes the dot product of the 2 vectors : position.velocity.

Specified by:

g in interface FieldEventDetector<T extends org.hipparchus.RealFieldElement<T>>

Specified by:

g in class FieldAbstractDetector<FieldApsideDetector<T extends org.hipparchus.RealFieldElement<T>>,T extends org.hipparchus.RealFieldElement<T>>

Parameters:

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

Returns:

value of the switching function

Throws:

OrekitException - if some specific error occurs