org.orekit.propagation.events
Class LongitudeDetector

java.lang.Object
  org.orekit.propagation.events.AbstractDetector
      org.orekit.propagation.events.LongitudeDetector

All Implemented Interfaces:

Serializable, EventDetector

public class LongitudeDetector
extends AbstractDetector

Detects when the spacecraft reaches a given local longitude.

The default implementation behaviour is to stop propagation when the longitude is reached. This can be changed by using provided constructors.

Since:

1.3

Version:

$Id: LongitudeDetector.java 14677 2015-11-25 14:52:39Z rodrigues $

Author:

chabaudp

See Also:

EventDetector, Serialized Form

Concurrency :

not thread-safe

Concurrency comment :

attributes are mutable and related to propagation.

Nested Class Summary

Nested classes/interfaces inherited from interface org.orekit.propagation.events.EventDetector

EventDetector.Action

Field Summary

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

DEFAULT_MAXCHECK, DEFAULT_THRESHOLD

Fields inherited from interface org.orekit.propagation.events.EventDetector

DECREASING, INCREASING, INCREASING_DECREASING

Constructor Summary

LongitudeDetector(double longitudeToDetect, Frame bodyFrame)
Constructor for the longitude detector.

LongitudeDetector(double longitudeToDetect, Frame bodyFrame, double maxCheck, double threshold)
Constructor for the longitude detector.

LongitudeDetector(double longitudeToDetect, Frame bodyFrame, double maxCheck, double threshold, EventDetector.Action action)
Constructor for the longitude detector.

LongitudeDetector(double longitudeToDetect, Frame bodyFrame, double maxCheck, double threshold, EventDetector.Action action, boolean remove)
Constructor for the longitude detector.

Method Summary

EventDetector.Action	eventOccurred(SpacecraftState s, boolean increasing, boolean forward) Handle a longitude reaching event and choose what to do next.
double	g(SpacecraftState s) Compute the value of the switching function.
Frame	getBodyFrame() Returns central body frame.
double	getLongitudeToDetect() Returns longitude to detect.
void	init(SpacecraftState s0, AbsoluteDate t) Initialize event handler at the start of a propagation.
boolean	shouldBeRemoved() This method is called after EventDetector.eventOccurred(org.orekit.propagation.SpacecraftState, boolean, boolean) has been triggered.

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

getMaxCheckInterval, getMaxIterationCount, getSlopeSelection, getThreshold, resetState

Methods inherited from class java.lang.Object

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

Constructor Detail

LongitudeDetector

public LongitudeDetector(double longitudeToDetect,
                         Frame bodyFrame)

Constructor for the longitude detector.

The default implementation behavior is to stop propagation when the expected longitude is reached.

Parameters:

longitudeToDetect - the longitude to detect

bodyFrame - the frame of the central body (take care to use a rotative frame to get the right longitude)

LongitudeDetector

public LongitudeDetector(double longitudeToDetect,
                         Frame bodyFrame,
                         double maxCheck,
                         double threshold)

Constructor for the longitude detector.

The default implementation behavior is to stop propagation when the expected longitude is reached.

Parameters:

longitudeToDetect - the longitude to detect

bodyFrame - the frame of the central body (take care to use a rotative frame to get the right longitude)

maxCheck - maximum check (see AbstractDetector)

threshold - threshold (see AbstractDetector)

LongitudeDetector

public LongitudeDetector(double longitudeToDetect,
                         Frame bodyFrame,
                         double maxCheck,
                         double threshold,
                         EventDetector.Action action)

Constructor for the longitude detector.

The default implementation behavior is to stop propagation when the expected longitude is reached.

Parameters:

longitudeToDetect - the longitude to detect

bodyFrame - the frame of the central body (take care to use a rotative frame to get the right longitude)

maxCheck - maximum check (see AbstractDetector)

threshold - threshold (see AbstractDetector)

action - action performed at longitude detection

LongitudeDetector

public LongitudeDetector(double longitudeToDetect,
                         Frame bodyFrame,
                         double maxCheck,
                         double threshold,
                         EventDetector.Action action,
                         boolean remove)

Constructor for the longitude detector.

The default implementation behavior is to stop propagation when the expected longitude is reached.

Parameters:

longitudeToDetect - the longitude to detect

bodyFrame - the frame of the central body (take care to use a rotative frame to get the right longitude)

maxCheck - maximum check (see AbstractDetector)

threshold - threshold (see AbstractDetector)

action - action performed at longitude detection

remove - true if detector should be removed

Since:

3.1

Method Detail

init

public void init(SpacecraftState s0,
                 AbsoluteDate t)

Description copied from class: AbstractDetector

Initialize event handler at the start of a propagation.

This method is called once at the start of the propagation. It may be used by the event handler to initialize some internal data if needed.

Specified by:

init in interface EventDetector

Overrides:

init in class AbstractDetector

Parameters:

s0 - initial state

t - target time for the integration

eventOccurred

public EventDetector.Action eventOccurred(SpacecraftState s,
                                          boolean increasing,
                                          boolean forward)
                                   throws OrekitException

Handle a longitude reaching event and choose what to do next.

The default implementation behavior is to stop propagation when the expected longitude is reached.

Specified by:

eventOccurred in interface EventDetector

Specified by:

eventOccurred in class AbstractDetector

Parameters:

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

increasing - if true, the value of the switching function increases when times increases around event

forward - if true, the integration variable (time) increases during integration.

Returns:

the action performed when the expected longitude is reached

Throws:

OrekitException - if some specific error occurs

shouldBeRemoved

public boolean shouldBeRemoved()

This method is called after EventDetector.eventOccurred(org.orekit.propagation.SpacecraftState, boolean, boolean) has been triggered. It returns true if the current detector should be removed after first event detection. WARNING: this method can be called only once a event has been triggered. Before, the value is not available.

Specified by:

shouldBeRemoved in interface EventDetector

Specified by:

shouldBeRemoved in class AbstractDetector

Returns:

true if the current detector should be removed after first event detection

g

public double g(SpacecraftState s)
         throws OrekitException

Description copied from class: AbstractDetector

Compute the value of the switching function. This function must be continuous (at least in its roots neighborhood), as the integrator will need to find its roots to locate the events.

Specified by:

g in interface EventDetector

Specified by:

g in class AbstractDetector

Parameters:

s - the current state information: date, kinematics, attitude for forces and events computation, mass provider, and additional states

Returns:

value of the switching function

Throws:

OrekitException - if some specific error occurs

getLongitudeToDetect

public double getLongitudeToDetect()

Returns longitude to detect.

Returns:

the longitude triggering the event.

getBodyFrame

public Frame getBodyFrame()

Returns central body frame.

Returns:

the frame of the central body