fr.cnes.sirius.patrius.events.detectors

Class StationToSatMutualVisibilityDetector

java.lang.Object

fr.cnes.sirius.patrius.events.AbstractDetector

fr.cnes.sirius.patrius.events.detectors.AbstractSignalPropagationDetector

fr.cnes.sirius.patrius.events.detectors.AbstractStationToSatDetector

fr.cnes.sirius.patrius.events.detectors.StationToSatMutualVisibilityDetector

All Implemented Interfaces:

EventDetector, Serializable

public class StationToSatMutualVisibilityDetector
extends AbstractStationToSatDetector

Mutual station to spacecraft visibility detector : the g function is positive only if the station's sensor sees the spacecraft's sensor AND the spacecraft's sensor sees the station's sensor.

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

This detector can take into account signal propagation duration through AbstractSignalPropagationDetector.setPropagationDelayType(PropagationDelayType, Frame) (default is signal being instantaneous).
Default linktype is VisibilityFromStationDetector.LinkType.DOWNLINK.

Since:

1.2

Version:

$Id$

Author:

Thomas Trapier

See Also:

Assembly, GeometricStationAntenna, 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.events.detectors.AbstractSignalPropagationDetector

AbstractSignalPropagationDetector.EventDatationType, AbstractSignalPropagationDetector.PropagationDelayType

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
StationToSatMutualVisibilityDetector(SensorModel sensorModel1, GeometricStationAntenna station, AngularCorrection correctionModel, boolean withMasking, double maxCheck, double threshold) Constructor for the mutual station to spacecraft visibility detector The default implementation behavior is to continue propagation when entering the eclipse and to stop propagation when exiting the eclipse.
StationToSatMutualVisibilityDetector(SensorModel sensorModel1, GeometricStationAntenna station, AngularCorrection correctionModel, boolean withMasking, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit) Constructor for the mutual station to spacecraft visibility detector
StationToSatMutualVisibilityDetector(SensorModel sensorModel1, GeometricStationAntenna station, AngularCorrection correctionModel, boolean withMasking, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit, boolean removeEntry, boolean removeExit) Constructor for the mutual station to spacecraft visibility detector
StationToSatMutualVisibilityDetector(SensorModel sensorModel1, GeometricStationAntenna station, AngularCorrection correctionModel, boolean withMasking, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit, boolean removeEntry, boolean removeExit, VisibilityFromStationDetector.LinkType linkTypeIn) Constructor for the mutual station to spacecraft visibility detector
StationToSatMutualVisibilityDetector(SensorModel sensorModel1, TopocentricFrame topoFrame, double[][] azimElevMask, AngularCorrection correctionModel, double maxCheck, double threshold) Constructor for the mutual station to spacecraft visibility detector The default implementation behavior is to continue propagation when entering the eclipse and to stop propagation when exiting the eclipse.
StationToSatMutualVisibilityDetector(SensorModel sensorModel1, TopocentricFrame topoFrame, double[][] azimElevMask, AngularCorrection correctionModel, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit) Constructor for the mutual station to spacecraft visibility detector
StationToSatMutualVisibilityDetector(SensorModel sensorModel1, TopocentricFrame topoFrame, double[][] azimElevMask, AngularCorrection correctionModel, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit, boolean removeEntry, boolean removeExit) Constructor for the mutual station to spacecraft visibility detector
StationToSatMutualVisibilityDetector(SensorModel sensorModel1, TopocentricFrame topoFrame, double[][] azimElevMask, AngularCorrection correctionModel, double maxCheck, double threshold, EventDetector.Action entry, EventDetector.Action exit, boolean removeEntry, boolean removeExit, VisibilityFromStationDetector.LinkType linkTypeIn) Constructor for the mutual station to spacecraft 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 state) Compute the value of the switching function.
void	init(SpacecraftState s0, AbsoluteDate t) Initialize event handler at the start of a propagation.
void	setPropagationDelayType(AbstractSignalPropagationDetector.PropagationDelayType propagationDelayType, Frame frame) Setter for the propagation delay computation type.
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.events.detectors.AbstractStationToSatDetector

getAssembly, getCorrectedVector, getCorrection, getLinkType, getMinMaskingDistance, getSensor, getStation, isMaskingCheck

Methods inherited from class fr.cnes.sirius.patrius.events.detectors.AbstractSignalPropagationDetector

getEmitter, getEpsilonSignalPropagation, getEventDatationType, getInertialFrame, getLinkTypeHandler, getMaxIterSignalPropagation, getOtherDate, getPropagationDelayType, getReceiver, getSignalEmissionDate, getSignalEmissionDate, getSignalReceptionDate, getSignalReceptionDate, setEpsilonSignalPropagation, setMaxIterSignalPropagation

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

StationToSatMutualVisibilityDetector

public StationToSatMutualVisibilityDetector(SensorModel sensorModel1,
                                            GeometricStationAntenna station,
                                            AngularCorrection correctionModel,
                                            boolean withMasking,
                                            double maxCheck,
                                            double threshold)

Constructor for the mutual station to spacecraft visibility detector

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

Parameters:

sensorModel1 - the sensor model the main part frame of the assembly must have a parent frame ! Make sure that the main target of this sensor model is the following station !

station - the ground station sensor geometric model.

correctionModel - the elevation correction model for the station

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 spacecraft and the station.

maxCheck - maximum checking interval (s)

threshold - convergence threshold (s)

StationToSatMutualVisibilityDetector

public StationToSatMutualVisibilityDetector(SensorModel sensorModel1,
                                            GeometricStationAntenna station,
                                            AngularCorrection correctionModel,
                                            boolean withMasking,
                                            double maxCheck,
                                            double threshold,
                                            EventDetector.Action entry,
                                            EventDetector.Action exit)

Constructor for the mutual station to spacecraft visibility detector

Parameters:

sensorModel1 - the sensor model the main part frame of the assembly must have a parent frame ! Make sure that the main target of this sensor model is the following station !

station - the ground station sensor geometric model.

correctionModel - the elevation correction model for the station

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 spacecraft and the station.

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

StationToSatMutualVisibilityDetector

public StationToSatMutualVisibilityDetector(SensorModel sensorModel1,
                                            GeometricStationAntenna station,
                                            AngularCorrection correctionModel,
                                            boolean withMasking,
                                            double maxCheck,
                                            double threshold,
                                            EventDetector.Action entry,
                                            EventDetector.Action exit,
                                            boolean removeEntry,
                                            boolean removeExit)

Constructor for the mutual station to spacecraft visibility detector

Parameters:

sensorModel1 - the sensor model the main part frame of the assembly must have a parent frame ! Make sure that the main target of this sensor model is the following station !

station - the ground station sensor geometric model.

correctionModel - the elevation correction model for the station

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 spacecraft and the station.

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 detector should be removed when entering the visibility zone

removeExit - true if detector should be removed when exiting the visibility zone

Since:

3.1

StationToSatMutualVisibilityDetector

public StationToSatMutualVisibilityDetector(SensorModel sensorModel1,
                                            GeometricStationAntenna station,
                                            AngularCorrection correctionModel,
                                            boolean withMasking,
                                            double maxCheck,
                                            double threshold,
                                            EventDetector.Action entry,
                                            EventDetector.Action exit,
                                            boolean removeEntry,
                                            boolean removeExit,
                                            VisibilityFromStationDetector.LinkType linkTypeIn)

Constructor for the mutual station to spacecraft visibility detector

Parameters:

sensorModel1 - the sensor model the main part frame of the assembly must have a parent frame ! Make sure that the main target of this sensor model is the following station !

station - the ground station sensor geometric model.

correctionModel - the elevation correction model for the station

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 spacecraft and the station.

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 detector should be removed when entering the visibility zone

removeExit - true if detector should be removed when exiting the visibility zone

linkTypeIn - the type of link (it can be uplink or downlink). Downlink means satellite to station.

Since:

4.10

StationToSatMutualVisibilityDetector

public StationToSatMutualVisibilityDetector(SensorModel sensorModel1,
                                            TopocentricFrame topoFrame,
                                            double[][] azimElevMask,
                                            AngularCorrection correctionModel,
                                            double maxCheck,
                                            double threshold)

Constructor for the mutual station to spacecraft visibility detector

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

Parameters:

sensorModel1 - the sensor model the main part frame of the assembly must have a parent frame ! Make sure that the main target of this sensor model is the following station !

topoFrame - the station's topocentric frame

azimElevMask - azimElevMask the azimuth - elevation mask (rad)

correctionModel - the elevation correction model for the station

maxCheck - maximum checking interval (s)

threshold - convergence threshold (s)

StationToSatMutualVisibilityDetector

public StationToSatMutualVisibilityDetector(SensorModel sensorModel1,
                                            TopocentricFrame topoFrame,
                                            double[][] azimElevMask,
                                            AngularCorrection correctionModel,
                                            double maxCheck,
                                            double threshold,
                                            EventDetector.Action entry,
                                            EventDetector.Action exit)

Constructor for the mutual station to spacecraft visibility detector

Parameters:

sensorModel1 - the sensor model the main part frame of the assembly must have a parent frame ! Make sure that the main target of this sensor model is the following station !

topoFrame - the station's topocentric frame

azimElevMask - azimElevMask the azimuth - elevation mask (rad)

correctionModel - the elevation correction model for the station

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

StationToSatMutualVisibilityDetector

public StationToSatMutualVisibilityDetector(SensorModel sensorModel1,
                                            TopocentricFrame topoFrame,
                                            double[][] azimElevMask,
                                            AngularCorrection correctionModel,
                                            double maxCheck,
                                            double threshold,
                                            EventDetector.Action entry,
                                            EventDetector.Action exit,
                                            boolean removeEntry,
                                            boolean removeExit)

Constructor for the mutual station to spacecraft visibility detector

Parameters:

sensorModel1 - the sensor model the main part frame of the assembly must have a parent frame ! Make sure that the main target of this sensor model is the following station !

topoFrame - the station's topocentric frame

azimElevMask - azimElevMask the azimuth - elevation mask (rad)

correctionModel - the elevation correction model for the station

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 detector should be removed when entering the visibility zone

removeExit - true if detector should be removed when exiting the visibility zone

StationToSatMutualVisibilityDetector

public StationToSatMutualVisibilityDetector(SensorModel sensorModel1,
                                            TopocentricFrame topoFrame,
                                            double[][] azimElevMask,
                                            AngularCorrection correctionModel,
                                            double maxCheck,
                                            double threshold,
                                            EventDetector.Action entry,
                                            EventDetector.Action exit,
                                            boolean removeEntry,
                                            boolean removeExit,
                                            VisibilityFromStationDetector.LinkType linkTypeIn)

Constructor for the mutual station to spacecraft visibility detector

Parameters:

sensorModel1 - the sensor model the main part frame of the assembly must have a parent frame ! Make sure that the main target of this sensor model is the following station !

topoFrame - the station's topocentric frame

azimElevMask - azimElevMask the azimuth - elevation mask (rad)

correctionModel - the elevation correction model for the station

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 detector should be removed when entering the visibility zone

removeExit - true if detector should be removed when exiting the visibility zone

linkTypeIn - the type of link (it can be uplink or downlink)

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

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

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

Overrides:

shouldBeRemoved in class AbstractDetector

Returns:

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

setPropagationDelayType

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

Setter for the 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 AbstractSignalPropagationDetector

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.

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.

Visibility from station only.

This function measures the angular distance between the current apparent vector to the spacecraft and the border of the station's field of view. It is positive when the spacecraft is in the field

More calculations are performed in case masking check is asked for: the distance between spacecraft's sensor line of sight and the occulting object is computed. This distance is positive if no masking occurs, negative otherwise.

Specified by:

g in interface EventDetector

Overrides:

g in class AbstractStationToSatDetector

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

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:

• inSensorSpacecraft: SensorModel
• correction: AngularCorrection
• station: GeometricStationAntenna

Returns:

a copy of the detector.