Package org.orekit.propagation.events

Class ApsideDetector

java.lang.Object

org.orekit.propagation.events.AbstractDetector<ApsideDetector>

org.orekit.propagation.events.ApsideDetector

All Implemented Interfaces:

EventDetector

public class ApsideDetector
extends AbstractDetector<ApsideDetector>

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 AbstractDetector.withHandler(EventHandler) 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:

• Propagator.addEventDetector(EventDetector)

Field Summary

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

DEFAULT_MAX_CHECK, DEFAULT_MAX_ITER, DEFAULT_THRESHOLD

Constructor Summary

Constructors

Modifier	Constructor	Description
	ApsideDetector(double keplerianPeriod)	Build a new instance.
	ApsideDetector(double threshold, Orbit orbit)	Build a new instance.
	ApsideDetector(Orbit orbit)	Build a new instance.
	ApsideDetector(EventDetectionSettings detectionSettings, EventHandler handler)	Public constructor with full parameters.
protected	ApsideDetector(ApsideEventFunction apsideEventFunction, EventDetectionSettings detectionSettings, EventHandler handler)	Protected constructor with full parameters.

Method Summary

Modifier and Type	Method	Description
protected ApsideDetector	create(EventDetectionSettings detectionSettings, EventHandler newHandler)	Build a new instance.
double	g(SpacecraftState s)	Compute the value of the switching function.

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

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.EventDetector

finish, getMaxCheckInterval, getMaxIterationCount, getThreshold, reset

Constructor Details

ApsideDetector

public ApsideDetector(double keplerianPeriod)

Build a new instance.

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

Parameters:

keplerianPeriod - estimate of the Keplerian period

Since:

12.1

ApsideDetector

public ApsideDetector(Orbit 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

ApsideDetector

public ApsideDetector(double threshold,
 Orbit 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

ApsideDetector

public ApsideDetector(EventDetectionSettings detectionSettings,
 EventHandler handler)

Public constructor with full parameters.

This constructor is public because otherwise all accessible ones would require an orbit.

Parameters:

detectionSettings - detection settings

handler - event handler to call at event occurrences

Since:

13.0

ApsideDetector

protected ApsideDetector(ApsideEventFunction apsideEventFunction,
 EventDetectionSettings detectionSettings,
 EventHandler handler)

Protected constructor with full parameters.

Parameters:

apsideEventFunction - event function

detectionSettings - detection settings

handler - event handler to call at event occurrences

Since:

14.0

Method Details

create

protected ApsideDetector create(EventDetectionSettings detectionSettings,
 EventHandler newHandler)

Build a new instance.

Specified by:

create in class AbstractDetector<ApsideDetector>

Parameters:

detectionSettings - detection settings

newHandler - event handler to call at event occurrences

Returns:

a new instance of the appropriate sub-type

g

public double g(SpacecraftState s)

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

Parameters:

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

Returns:

value of the switching function