fr.cnes.sirius.patrius.events.sensor

Class SensorVisibilityDetector

java.lang.Object

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

fr.cnes.sirius.patrius.events.sensor.SensorVisibilityDetector

All Implemented Interfaces:

EventDetector, Serializable

public class SensorVisibilityDetector
extends AbstractDetector

Event detector for the visibility of a sensor. The g function is positive if none of the inhibition target is in its inhibition field, no masking object cuts the line segment between the sensor and the target and if the main target is in the field of view.

The default implementation behaviour is to continue propagation when entering the zone and to stop when exiting the zone. This can be changed by using provided constructors.

This detector can takes into account signal propagation duration through AbstractDetector.setPropagationDelayType(PropagationDelayType, fr.cnes.sirius.patrius.frames.Frame) (default is signal being instantaneous).

Since:

1.2

Version:

$Id$

Author:

Thomas Trapier

See Also:

SensorModel, Serialized Form

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

AbstractDetector.PropagationDelayType

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

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

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

DECREASING, INCREASING, INCREASING_DECREASING

Constructor Summary

Constructors

Constructor and Description
SensorVisibilityDetector(Assembly assembly, String partName, double maxCheck, double threshold) Constructor for the "visibility view" detector The default implementation behaviour is to continue propagation when entering the zone and to stop when exiting the zone.
SensorVisibilityDetector(Assembly assembly, String partName, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit) Constructor for the "visibility view" detector
SensorVisibilityDetector(SensorModel sensorModel, double maxCheck, double threshold) Constructor for the "visibility view" detector The default implementation behaviour is to continue propagation when entering the zone and to stop when exiting the zone.
SensorVisibilityDetector(SensorModel sensorModel, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit) Constructor for the "visibility" detector
SensorVisibilityDetector(SensorModel sensorModel, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit, boolean removeEntry, boolean removeExit) Constructor for the "visibility" 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.
int	getInhibitionNumber() Get the inhibition number.
String	getMaskingObjectName() Get the masking object.
String	getMaskingPartName() Get the masking part.
SensorModel	getSensor() Get the sensor.
void	init(SpacecraftState s0, AbsoluteDate t) Initialize event handler at the start of a propagation.
void	setPropagationDelayType(AbstractDetector.PropagationDelayType propagationDelayType, Frame frame) Setter for propagation delay computation type.

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

getActionAtEntry, getActionAtExit, getInertialFrame, getMaxCheckInterval, getMaxIterationCount, getPropagationDelayType, getSignalEmissionDate, getSignalReceptionDate, getSlopeSelection, getThreshold, isRemoveAtEntry, isRemoveAtExit, logEventsOverTimeInterval, resetState, setEpsilonSignalPropagation, setMaxCheckInterval, setMaxIterSignalPropagation, shouldBeRemoved

Methods inherited from class java.lang.Object

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

Constructor Detail

SensorVisibilityDetector

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

Constructor for the "visibility view" detector The default implementation behaviour is to continue propagation when entering the zone and to stop 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)

SensorVisibilityDetector

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

Constructor for the "visibility 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

SensorVisibilityDetector

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

Constructor for the "visibility view" detector The default implementation behaviour is to continue propagation when entering the zone and to stop 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)

SensorVisibilityDetector

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

Constructor for the "visibility" 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

SensorVisibilityDetector

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

Constructor for the "visibility" 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)

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

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

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

Overrides:

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

getInhibitionNumber

public int getInhibitionNumber()

Get the inhibition number.

Returns:

the first inhibition target to enter the field (to be used in the user eventOccured method)

getMaskingObjectName

public String getMaskingObjectName()

Get the masking object.

Returns:

the first masking object name (to be used in the user eventOccured method)

getMaskingPartName

public String getMaskingPartName()

Get the masking part.

Returns:

first masking spacecraft's part name if the first masking part is a spacecraft, "none" otherwise (to be used in the user eventOccured method)

getAssembly

public Assembly getAssembly()

Get the assembly.

Returns:

the assembly

getSensor

public SensorModel getSensor()

Get the sensor.

Returns:

the sensor

setPropagationDelayType

public void setPropagationDelayType(AbstractDetector.PropagationDelayType propagationDelayType,
                                    Frame frame)

Setter for propagation delay computation type. Warning: check Javadoc of detector to see if detector takes into account propagation time delay. if not, signals are always considered instantaneous. The provided frame is used to compute the signal propagation when delay is taken into account.

Overrides:

setPropagationDelayType in class AbstractDetector

Parameters:

propagationDelayType - propagation delay type used in events computation

frame - frame to use for signal propagation with delay (may be null if propagation delay type is considered instantaneous). Warning: the usage of a pseudo inertial frame is tolerated, however it will lead to some inaccuracies due to the non-invariance of the frame with respect to time. For this reason, it is suggested to use the ICRF frame or a frame which is frozen with respect to the ICRF.

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.