fr.cnes.sirius.patrius.events.detectors

Class LongitudeDetector

java.lang.Object

fr.cnes.sirius.patrius.events.AbstractDetector

fr.cnes.sirius.patrius.events.detectors.LongitudeDetector

All Implemented Interfaces:

EventDetector, Serializable

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 17582 2017-05-10 12:58:16Z bignon $

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 fr.cnes.sirius.patrius.events.EventDetector

EventDetector.Action

Field Summary

Fields inherited from class fr.cnes.sirius.patrius.events.AbstractDetector

actionAtEntry, actionAtExit, DEFAULT_MAXCHECK, DEFAULT_MAXITER, DEFAULT_THRESHOLD, removeAtEntry, removeAtExit, shouldBeRemovedFlag

Fields inherited from interface fr.cnes.sirius.patrius.events.EventDetector

DECREASING, INCREASING, INCREASING_DECREASING

Constructor Summary

Constructors

Constructor and Description
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.
LongitudeDetector(double longitudeToDetect, Frame bodyFrame, double maxCheck, double threshold, EventDetector.Action action, boolean remove, int slopeSelection) Complete constructor for the longitude detector.

Method Summary

Modifier and Type	Method and Description
EventDetector	copy() A copy of the detector.
EventDetector.Action	eventOccurred(SpacecraftState s, boolean increasing, boolean forward) Handle a longitude reaching event and choose what to do next.
boolean	filterEvent(SpacecraftState state, boolean increasing, boolean forward) Filter last event: returns true if the last event is a false detection, false otherwise.
double	g(SpacecraftState state) 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.

Methods inherited from class fr.cnes.sirius.patrius.events.AbstractDetector

getActionAtEntry, getActionAtExit, getMaxCheckInterval, getMaxIterationCount, getSlopeSelection, getThreshold, isRemoveAtEntry, isRemoveAtExit, logEventsOverTimeInterval, resetState, setMaxCheckInterval, setMaxIter, shouldBeRemoved

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 in INCREASING_DECREASING mode.

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 set to INCREASING_DECREASING mode.

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 set to INCREASING_DECREASING mode.

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

LongitudeDetector

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

Complete constructor for the longitude detector.

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

slopeSelection - NodeDetector.ASCENDING for ascending node detection,
NodeDetector.DESCENDING for descending node detection,
NodeDetector.ASCENDING_DESCENDING for both ascending and descending node detection.

Since:

4.13

Method Detail

init

public void init(SpacecraftState s0,
                 AbsoluteDate t)

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 PatriusException

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

Overrides:

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:

PatriusException - if some specific error occurs

g

public double g(SpacecraftState state)
         throws PatriusException

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:

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

Returns:

value of the switching function

Throws:

PatriusException - if some specific error occurs

filterEvent

public boolean filterEvent(SpacecraftState state,
                           boolean increasing,
                           boolean forward)
                    throws PatriusException

Filter last event: returns true if the last event is a false detection, false otherwise.

This method is called right before EventDetector.eventOccurred(SpacecraftState, boolean, boolean) method.

This may be useful in order to filter some events in particular when angles are at stake (see for example LocalTimeAngleDetector).

Specified by:

filterEvent in interface EventDetector

Overrides:

filterEvent in class AbstractDetector

Parameters:

state - state at last event occurrence

increasing - if true, the value of the switching function increases when times increases around event (note that increase is measured with respect to physical time, not with respect to propagation which may go backward in time)

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

Returns:

true if the last event is a false detection, false otherwise

Throws:

PatriusException - thrown if computation failed for some reasons

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

copy

public EventDetector copy()

A copy of the detector. By default copy is deep. If not, detector javadoc will specify which attribute is not fully copied. In that case, the attribute reference is passed.

The following attributes are not deeply copied:

• earthcentralBoyFrame: Frame

Returns:

a copy of the detector.