fr.cnes.sirius.patrius.events.sensor

Class SatToSatMutualVisibilityDetector

java.lang.Object

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

fr.cnes.sirius.patrius.events.sensor.SatToSatMutualVisibilityDetector

All Implemented Interfaces:

EventDetector, MultiEventDetector, Serializable

public class SatToSatMutualVisibilityDetector
extends AbstractDetector
implements MultiEventDetector

Mutual spacecraft visibility detector : the g function is positive only if each spacecraft is in the main field of view of the other one's sensor. In a single spacecraft propagation mode ( Propagator), this event detector shall be used in the propagation of a main spacecraft, and will use internally a given propagator to get the position of the secondary spacecraft.

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

Since:

1.2

Version:

$Id$

Author:

Thomas Trapier

See Also:

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.multi.MultiEventDetector

DECREASING, INCREASING, INCREASING_DECREASING

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

DECREASING, INCREASING, INCREASING_DECREASING

Constructor Summary

Constructors

Constructor and Description
SatToSatMutualVisibilityDetector(SensorModel mainSensorModel, SensorModel secondarySensorModel, Propagator secondSpacecraftPropagator, boolean withMasking, double maxCheck, double threshold) Constructor to be used for single spacecraft propagation only (Propagator).
SatToSatMutualVisibilityDetector(SensorModel mainSensorModel, SensorModel secondarySensorModel, Propagator secondSpacecraftPropagator, boolean withMasking, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit) Constructor to be used for single spacecraft propagation only (Propagator).
SatToSatMutualVisibilityDetector(SensorModel mainSensorModel, SensorModel secondarySensorModel, Propagator secondSpacecraftPropagator, boolean withMasking, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit, boolean removeEntry, boolean removeExit) Constructor to be used for single spacecraft propagation only (Propagator).
SatToSatMutualVisibilityDetector(String mainSpacecraftId, String secondarySpacecraftId, SensorModel mainSensorModel, SensorModel secondarySensorModel, boolean withMasking, double maxCheck, double threshold) Constructor to be used for multi spacecraft propagation only ( MultiPropagator).
SatToSatMutualVisibilityDetector(String mainSpacecraftId, String secondarySpacecraftId, SensorModel mainSensorModel, SensorModel secondarySensorModel, boolean withMasking, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit) Constructor to be used for multi spacecraft propagation only ( MultiPropagator).
SatToSatMutualVisibilityDetector(String mainSpacecraftId, String secondarySpacecraftId, SensorModel mainSensorModel, SensorModel secondarySensorModel, boolean withMasking, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit, boolean removeEntry, boolean removeExit) Constructor to be used for multi-spacecraft propagation only ( MultiPropagator).

Method Summary

Modifier and Type	Method and Description
EventDetector	copy() A copy of the detector.
EventDetector.Action	eventOccurred(Map<String,SpacecraftState> s, boolean increasing, boolean forward) Handle an event and choose what to do next.
EventDetector.Action	eventOccurred(SpacecraftState s, boolean increasing, boolean forward) Handle an event and choose what to do next.
double	g(Map<String,SpacecraftState> s) Compute the value of the switching function.
double	g(SpacecraftState s) Compute the value of the switching function.
String	getInMainSpacecraftId() Get the main spacecraft id.
String	getInSecondarySpacecraftId() Get the secondary spacecraft id.
Assembly	getMainSpacecraft() Get the main assembly to consider.
Assembly	getSecondarySpacecraft() Get the secondary assembly to consider.
SensorModel	getSensorMainSpacecraft() Get the main spacecraft sensor.
SensorModel	getSensorSecondarySpacecraft() Get the secondary spacecraft sensor.
void	init(Map<String,SpacecraftState> s0, AbsoluteDate t) Initialize event handler at the start of a propagation.
void	init(SpacecraftState s0, AbsoluteDate t) Initialize event handler at the start of a propagation.
boolean	isMaskingCheck() Check maskings.
Map<String,SpacecraftState>	resetStates(Map<String,SpacecraftState> oldStates) Reset the states (including additional states) prior to continue 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

Methods inherited from interface fr.cnes.sirius.patrius.propagation.events.multi.MultiEventDetector

getMaxCheckInterval, getMaxIterationCount, getSlopeSelection, getThreshold

Constructor Detail

SatToSatMutualVisibilityDetector

public SatToSatMutualVisibilityDetector(SensorModel mainSensorModel,
                                        SensorModel secondarySensorModel,
                                        Propagator secondSpacecraftPropagator,
                                        boolean withMasking,
                                        double maxCheck,
                                        double threshold)

Constructor to be used for single spacecraft propagation only (Propagator). Constructor for the mutual spacecraft to spacecraft visibility detector.

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

Parameters:

mainSensorModel - the sensor model to consider for the main spacecraft. The secondary sensor model must be its main target !

secondarySensorModel - the sensor model to consider for the secondary spacecraft. The main sensor model must be its main target !

secondSpacecraftPropagator - the propagator for the secondary spacecraft

withMasking - set true to compute maskings of each spacecrafts' sensors : in this case, there is no visibility if one of the masking bodies of both sensors is between the satellites.

maxCheck - maximum checking interval (s)

threshold - convergence threshold (s)

SatToSatMutualVisibilityDetector

public SatToSatMutualVisibilityDetector(SensorModel mainSensorModel,
                                        SensorModel secondarySensorModel,
                                        Propagator secondSpacecraftPropagator,
                                        boolean withMasking,
                                        double maxCheck,
                                        double threshold,
                                        EventDetector.Action entry,
                                        EventDetector.Action exit)

Constructor to be used for single spacecraft propagation only (Propagator). Constructor for the mutual spacecraft to spacecraft visibility detector.

Parameters:

mainSensorModel - the sensor model to consider for the main spacecraft. The secondary sensor model must be its main target !

secondarySensorModel - the sensor model to consider for the secondary spacecraft. The main sensor model must be its main target !

secondSpacecraftPropagator - the propagator for the secondary spacecraft

withMasking - set true to compute maskings of each spacecrafts' sensors : in this case, there is no visibility if one of the masking bodies of both sensors is between the satellites.

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

SatToSatMutualVisibilityDetector

public SatToSatMutualVisibilityDetector(SensorModel mainSensorModel,
                                        SensorModel secondarySensorModel,
                                        Propagator secondSpacecraftPropagator,
                                        boolean withMasking,
                                        double maxCheck,
                                        double threshold,
                                        EventDetector.Action entry,
                                        EventDetector.Action exit,
                                        boolean removeEntry,
                                        boolean removeExit)

Constructor to be used for single spacecraft propagation only (Propagator). Constructor for the mutual spacecraft to spacecraft visibility detector.

Parameters:

mainSensorModel - the sensor model to consider for the main spacecraft. The secondary sensor model must be its main target

secondarySensorModel - the sensor model to consider for the secondary spacecraft. The main sensor model must be its main target

secondSpacecraftPropagator - the propagator for the secondary spacecraft

withMasking - true to compute maskings of each spacecrafts' sensors : in this case, there is no visibility if one of the masking bodies of both sensors is between the satellites.

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

SatToSatMutualVisibilityDetector

public SatToSatMutualVisibilityDetector(String mainSpacecraftId,
                                        String secondarySpacecraftId,
                                        SensorModel mainSensorModel,
                                        SensorModel secondarySensorModel,
                                        boolean withMasking,
                                        double maxCheck,
                                        double threshold)

Constructor to be used for multi spacecraft propagation only ( MultiPropagator). Constructor for the mutual spacecraft to spacecraft visibility detector.

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

Parameters:

mainSpacecraftId - id of the main spacecraft

secondarySpacecraftId - id of the secondary spacecraft

mainSensorModel - the sensor model to consider for the main spacecraft. The secondary sensor model must be its main target !

secondarySensorModel - the sensor model to consider for the secondary spacecraft. The main sensor model must be its main target !

withMasking - set true to compute maskings of each spacecrafts' sensors : in this case, there is no visibility if one of the masking bodies of both sensors is between the satellites.

maxCheck - maximum checking interval (s)

threshold - convergence threshold (s)

Since:

3.0

SatToSatMutualVisibilityDetector

public SatToSatMutualVisibilityDetector(String mainSpacecraftId,
                                        String secondarySpacecraftId,
                                        SensorModel mainSensorModel,
                                        SensorModel secondarySensorModel,
                                        boolean withMasking,
                                        double maxCheck,
                                        double threshold,
                                        EventDetector.Action entry,
                                        EventDetector.Action exit)

Constructor to be used for multi spacecraft propagation only ( MultiPropagator). Constructor for the mutual spacecraft to spacecraft visibility detector.

Parameters:

mainSpacecraftId - id of the main spacecraft

secondarySpacecraftId - id of the secondary spacecraft

mainSensorModel - the sensor model to consider for the main spacecraft. The secondary sensor model must be its main target !

secondarySensorModel - the sensor model to consider for the secondary spacecraft. The main sensor model must be its main target !

withMasking - set true to compute maskings of each spacecrafts' sensors : in this case, there is no visibility if one of the masking bodies of both sensors is between the satellites.

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

Since:

3.0

SatToSatMutualVisibilityDetector

public SatToSatMutualVisibilityDetector(String mainSpacecraftId,
                                        String secondarySpacecraftId,
                                        SensorModel mainSensorModel,
                                        SensorModel secondarySensorModel,
                                        boolean withMasking,
                                        double maxCheck,
                                        double threshold,
                                        EventDetector.Action entry,
                                        EventDetector.Action exit,
                                        boolean removeEntry,
                                        boolean removeExit)

Constructor to be used for multi-spacecraft propagation only ( MultiPropagator). Constructor for the mutual spacecraft to spacecraft visibility detector.

Parameters:

mainSpacecraftId - id of the main spacecraft

secondarySpacecraftId - id of the secondary spacecraft

mainSensorModel - the sensor model to consider for the main spacecraft. The secondary sensor model must be its main target

secondarySensorModel - the sensor model to consider for the secondary spacecraft. The main sensor model must be its main target

withMasking - true to compute maskings of each spacecrafts' sensors : in this case, there is no visibility if one of the masking bodies of both sensors is between the satellites.

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

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

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

getSensorMainSpacecraft

public SensorModel getSensorMainSpacecraft()

Get the main spacecraft sensor.

Returns:

the main spacecraft sensor.

getMainSpacecraft

public Assembly getMainSpacecraft()

Get the main assembly to consider.

Returns:

the main assembly to consider.

getSensorSecondarySpacecraft

public SensorModel getSensorSecondarySpacecraft()

Get the secondary spacecraft sensor.

Returns:

the secondary spacecraft sensor.

getSecondarySpacecraft

public Assembly getSecondarySpacecraft()

Get the secondary assembly to consider.

Returns:

the secondary assembly to consider

isMaskingCheck

public boolean isMaskingCheck()

Check maskings.

Returns:

true if maskings must be computed

getInMainSpacecraftId

public String getInMainSpacecraftId()

Get the main spacecraft id.

Returns:

the main spacecraft id

getInSecondarySpacecraftId

public String getInSecondarySpacecraftId()

Get the secondary spacecraft id.

Returns:

the secondary spacecraft id

init

public void init(Map<String,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 MultiEventDetector

Parameters:

s0 - map of initial states

t - target time for the integration

g

public double g(Map<String,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 MultiEventDetector

Parameters:

s - the current states information: date, kinematics, attitudes for forces and events computation, and additional states for each states

Returns:

value of the switching function

Throws:

PatriusException - if some specific error occurs

eventOccurred

public EventDetector.Action eventOccurred(Map<String,SpacecraftState> s,
                                          boolean increasing,
                                          boolean forward)
                                   throws PatriusException

Handle an event and choose what to do next.

The scheduling between this method and the MultiOrekitStepHandler 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 MultiOrekitStepNormalizer 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 MultiEventDetector interface and the MultiOrekitFixedStepHandler 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 MultiOrekitStepHandler and to the size of the fixed step for MultiOrekitFixedStepHandler.

Specified by:

eventOccurred in interface MultiEventDetector

Parameters:

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

resetStates

public Map<String,SpacecraftState> resetStates(Map<String,SpacecraftState> oldStates)
                                        throws PatriusException

Reset the states (including additional states) prior to continue propagation.

This method is called after the step handler has returned and before the next step is started, but only when MultiEventDetector.eventOccurred(java.util.Map<java.lang.String, fr.cnes.sirius.patrius.propagation.SpacecraftState>, boolean, boolean) has itself returned the EventDetector.Action.RESET_STATE indicator. It allows the user to reset the state for the next step, without perturbing the step handler of the finishing step. If the MultiEventDetector.eventOccurred(java.util.Map<java.lang.String, fr.cnes.sirius.patrius.propagation.SpacecraftState>, boolean, boolean) never returns the EventDetector.Action.RESET_STATE indicator, this function will never be called, and it is safe to simply return null.

Specified by:

resetStates in interface MultiEventDetector

Parameters:

oldStates - old states

Returns:

new states

Throws:

PatriusException - if the states cannot be reseted

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 interface MultiEventDetector

Specified by:

shouldBeRemoved in class AbstractDetector

Returns:

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

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:

• inSensorMainSpacecraft: SensorModel
• inSensorSecondarySpacecraft: SensorModel
• secondPropagator: Propagator

Specified by:

copy in interface EventDetector

Returns:

a copy of the detector.