fr.cnes.sirius.patrius.events.sensor

Class RFVisibilityDetector

java.lang.Object

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

fr.cnes.sirius.patrius.events.sensor.RFVisibilityDetector

All Implemented Interfaces:

EventDetector, Serializable

public class RFVisibilityDetector
extends AbstractDetector

Finder for ground station / satellite RF visibility events.

The default implementation behavior is to continue propagation at raising and to stop propagation at setting. This can be changed by This can be changed by using provided constructors.

Since:

1.2

Version:

$Id$

Author:

Tiziana Sabatini

See Also:

EventDetector, 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 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
RFVisibilityDetector(RFLinkBudgetModel linkBudgetModel, double linkBudgetThreshold, double maxCheck, double threshold) Constructor for the sensor masking detector.
RFVisibilityDetector(RFLinkBudgetModel linkBudgetModel, double linkBudgetThreshold, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit) Constructor for the sensor masking detector.
RFVisibilityDetector(RFLinkBudgetModel linkBudgetModel, double linkBudgetThreshold, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit, boolean removeEntry, boolean removeExit) Constructor for the sensor masking 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.
RFLinkBudgetModel	getLbModel() Get the RF link budget model.
double	getLbThreshold() Get the RF link budget threshold.
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, init, resetState

Methods inherited from class java.lang.Object

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

Constructor Detail

RFVisibilityDetector

public RFVisibilityDetector(RFLinkBudgetModel linkBudgetModel,
                            double linkBudgetThreshold,
                            double maxCheck,
                            double threshold)

Constructor for the sensor masking detector.

The default implementation behaviour is to continue propagation when entering the region of RF visibility and to stop when exiting.

Parameters:

linkBudgetModel - the model for the computation of the link budget

linkBudgetThreshold - link budget threshold for the nominal mode (dB)

maxCheck - the maximal checking interval (s)

threshold - the convergence threshold (s)

RFVisibilityDetector

public RFVisibilityDetector(RFLinkBudgetModel linkBudgetModel,
                            double linkBudgetThreshold,
                            double maxCheck,
                            double threshold,
                            EventDetector.Action entry,
                            EventDetector.Action exit)

Constructor for the sensor masking detector.

Parameters:

linkBudgetModel - the model for the computation of the link budget

linkBudgetThreshold - link budget threshold for the nominal mode (dB)

maxCheck - the maximal checking interval (s)

threshold - the convergence threshold (s)

entry - when entering the region of RF visibility.

exit - when exiting the region of RF visibility.

RFVisibilityDetector

public RFVisibilityDetector(RFLinkBudgetModel linkBudgetModel,
                            double linkBudgetThreshold,
                            double maxCheck,
                            double threshold,
                            EventDetector.Action entry,
                            EventDetector.Action exit,
                            boolean removeEntry,
                            boolean removeExit)

Constructor for the sensor masking detector.

Parameters:

linkBudgetModel - the model for the computation of the link budget

linkBudgetThreshold - link budget threshold for the nominal mode (dB)

maxCheck - the maximal checking interval (s)

threshold - the convergence threshold (s)

entry - when entering the region of RF visibility.

exit - when exiting the region of RF visibility.

removeEntry - true if entering the region of RF visibility.

removeExit - true if exiting the region of RF visibility.

Since:

3.1

Method Detail

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

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()

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

g

public double g(SpacecraftState s)
         throws PatriusException

Compute the value of the switching function. This function becomes positive when entering the region of RF visibility and negative when exiting.

Specified by:

g in interface EventDetector

Specified by:

g in class AbstractDetector

Parameters:

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

Returns:

value of the switching function

Throws:

PatriusException - if some specific error occurs

getLbModel

public RFLinkBudgetModel getLbModel()

Get the RF link budget model.

Returns:

the RF link budget model

getLbThreshold

public double getLbThreshold()

Get the RF link budget threshold.

Returns:

the RF link budget threshold

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:

• lbModel: RFLinkBudgetModel

Returns:

a copy of the detector.