fr.cnes.sirius.patrius.events.sensor

Class TargetInFieldOfViewDetector

java.lang.Object

fr.cnes.sirius.patrius.propagation.events.AbstractDetector

fr.cnes.sirius.patrius.events.sensor.TargetInFieldOfViewDetector

All Implemented Interfaces:

EventDetector, Serializable

public class TargetInFieldOfViewDetector
extends AbstractDetector

Since:

1.2

Version:

$Id$

Author:

Thomas Trapier

See Also:

SensorModel, Serialized Form

Description :

Event detector for the main target visibility of a sensor. The g function is positive if the main target is in the field of view.

The default implementation behavior is to continue propagation when entering the zone and to stop propagation when exiting the zone. This can be changed by using one of the provided contructors.

Concurrency :

not thread-safe

Concurrency comment :

the direct use of a not thread-safe Assembly makes this class not thread-safe itself

Nested Class Summary

Nested classes/interfaces inherited from interface fr.cnes.sirius.patrius.propagation.events.EventDetector

EventDetector.Action

Field Summary

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

DEFAULT_MAXCHECK, DEFAULT_THRESHOLD

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

DECREASING, INCREASING, INCREASING_DECREASING

Constructor Summary

Constructors

Constructor and Description
TargetInFieldOfViewDetector(Assembly assembly, String partName, double maxCheck, double threshold) Constructor for the "main target in field of view" detector
TargetInFieldOfViewDetector(Assembly assembly, String partName, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit) Constructor for the "main target in field of view" detector
TargetInFieldOfViewDetector(SensorModel sensorModel, double maxCheck, double threshold) Constructor for the "main target in field of view" detector
TargetInFieldOfViewDetector(SensorModel sensorModel, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit) Constructor for the "main target in field of view" detector
TargetInFieldOfViewDetector(SensorModel sensorModel, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit, boolean removeEntry, boolean removeExit) Constructor for the "main target in field of view" 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 an event and choose what to do next.
double	g(SpacecraftState s) Compute the value of the switching function.
Assembly	getAssembly() Get the assembly.
SensorModel	getSensor() Get the sensor.
void	init(SpacecraftState s0, AbsoluteDate t) Initialize event handler at the start of a propagation.
boolean	shouldBeRemoved() This method is called after EventDetector.eventOccurred(fr.cnes.sirius.patrius.propagation.SpacecraftState, boolean, boolean) has been triggered.

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

TargetInFieldOfViewDetector

public TargetInFieldOfViewDetector(Assembly assembly,
                                   String partName,
                                   double maxCheck,
                                   double threshold)

Constructor for the "main target in field of view" detector

The default implementation behavior is to continue propagation when entering the zone and to stop propagation when exiting the zone.

Parameters:

assembly - the assembly to consider (its main part frame must have a parent frame !!)

partName - the name of the part that supports the sensor

maxCheck - maximum checking interval (s)

threshold - convergence threshold (s)

TargetInFieldOfViewDetector

public TargetInFieldOfViewDetector(Assembly assembly,
                                   String partName,
                                   double maxCheck,
                                   double threshold,
                                   EventDetector.Action entry,
                                   EventDetector.Action exit)

Constructor for the "main target in field of view" detector

Parameters:

assembly - the assembly to consider (its main part frame must have a parent frame !!)

partName - the name of the part that supports the sensor

maxCheck - maximum checking interval (s)

threshold - convergence threshold (s)

entry - action performed when entering the visibility zone

exit - action performed when exiting the visibility zone

TargetInFieldOfViewDetector

public TargetInFieldOfViewDetector(SensorModel sensorModel,
                                   double maxCheck,
                                   double threshold)

Constructor for the "main target in field of view" detector

The default implementation behavior is to continue propagation when entering the zone and to stop propagation when exiting the zone.

Parameters:

sensorModel - the sensor model (the main part frame of the assembly must have a parent frame !!)

maxCheck - maximum checking interval (s)

threshold - convergence threshold (s)

TargetInFieldOfViewDetector

public TargetInFieldOfViewDetector(SensorModel sensorModel,
                                   double maxCheck,
                                   double threshold,
                                   EventDetector.Action entry,
                                   EventDetector.Action exit)

Constructor for the "main target in field of view" detector

Parameters:

sensorModel - the sensor model (the main part frame of the assembly must have a parent frame !!)

maxCheck - maximum checking interval (s)

threshold - convergence threshold (s)

entry - action performed when entering the visibility zone

exit - action performed when exiting the visibility zone

TargetInFieldOfViewDetector

public TargetInFieldOfViewDetector(SensorModel sensorModel,
                                   double maxCheck,
                                   double threshold,
                                   EventDetector.Action entry,
                                   EventDetector.Action exit,
                                   boolean removeEntry,
                                   boolean removeExit)

Constructor for the "main target in field of view" detector

Parameters:

sensorModel - the sensor model (the main part frame of the assembly must have a parent frame !!)

maxCheck - maximum checking interval (s)

threshold - convergence threshold (s)

entry - action performed when entering the visibility zone

exit - action performed when exiting the visibility zone

removeEntry - true if entering the visibility zone

removeExit - true if exiting the visibility zone

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

g

public double g(SpacecraftState s)
         throws PatriusException

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:

PatriusException - if some specific error occurs

eventOccurred

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

Description copied from class: AbstractDetector

Handle an event and choose what to do next.

The scheduling between this method and the PatriusStepHandler method handleStep() is to call this method first and handleStep afterwards. This scheduling allows the propagator to pass true as the isLast parameter to the step handler to make it aware the step will be the last one if this method returns EventDetector.Action.STOP. As the interpolator may be used to navigate back throughout the last step (as OrekitStepNormalizer does for example), user code called by this method and user code called by step handlers may experience apparently out of order values of the independent time variable. As an example, if the same user object implements both this EventDetector interface and the OrekitFixedStepHandler interface, a forward integration may call its eventOccurred method with a state at 2000-01-01T00:00:10 first and call its handleStep method with a state at 2000-01-01T00:00:09 afterwards. Such out of order calls are limited to the size of the integration step for variable step handlers and to the size of the fixed step for fixed step handlers.

Specified by:

eventOccurred in interface EventDetector

Specified by:

eventOccurred in class AbstractDetector

Parameters:

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

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:

one of EventDetector.Action.STOP, EventDetector.Action.RESET_STATE, EventDetector.Action.RESET_DERIVATIVES, EventDetector.Action.CONTINUE

Throws:

PatriusException - if some specific error occurs

shouldBeRemoved

public boolean shouldBeRemoved()

Description copied from class: AbstractDetector

This method is called after EventDetector.eventOccurred(fr.cnes.sirius.patrius.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

getAssembly

public Assembly getAssembly()

Get the assembly.

Returns:

the assembly

getSensor

public SensorModel getSensor()

Get the sensor.

Returns:

the sensor

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:

• sensor: SensorModel

Returns:

a copy of the detector.