fr.cnes.sirius.patrius.events.detectors

Class VisibilityFromStationDetector

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.VisibilityFromStationDetector

All Implemented Interfaces:

EventDetector, Serializable

public class VisibilityFromStationDetector
extends AbstractStationToSatDetector

Finder for satellite apparent entering in a station's field of view.

The tropospheric correction used can be set by the user.

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

This detector can takes into account signal propagation duration through AbstractSignalPropagationDetector.setPropagationDelayType(PropagationDelayType, Frame) (default is signal being instantaneous).

Since:

1.1

Version:

$Id$

Author:

Thomas Trapier

See Also:

TroposphericCorrection, EventDetector, 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

Modifier and Type	Class and Description
static class	VisibilityFromStationDetector.LinkType Type of link (it can be uplink or downlink).

Nested classes/interfaces inherited from class fr.cnes.sirius.patrius.events.detectors.AbstractSignalPropagationDetector

AbstractSignalPropagationDetector.DatationChoice, AbstractSignalPropagationDetector.PropagationDelayType

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

EventDetector.Action

Field Summary

Fields

Modifier and Type	Field and Description
static int	RAISING Flag for raising detection (slopeSelection = 0).
static int	RAISING_SETTING Flag for raising/setting detection (slopeSelection = 2).
static int	SETTING Flag for setting detection (slopeSelection = 1).

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
VisibilityFromStationDetector(GeometricStationAntenna stationModel, AngularCorrection correctionModel, double maxCheck, double threshold, EventDetector.Action raising, EventDetector.Action setting, boolean removeRaising, boolean removeSetting, VisibilityFromStationDetector.LinkType linkTypeIn) Build a new apparent elevation detector with parameterizable tropospheric correction.
VisibilityFromStationDetector(GeometricStationAntenna stationModel, AngularCorrection correctionModel, double maxCheck, double threshold, EventDetector.Action raising, EventDetector.Action setting, VisibilityFromStationDetector.LinkType linkTypeIn) Build a new apparent elevation detector with parameterizable tropospheric correction.
VisibilityFromStationDetector(GeometricStationAntenna stationModel, AngularCorrection correctionModel, double maxCheck, double threshold, VisibilityFromStationDetector.LinkType linkTypeIn) Build a new apparent elevation detector with parameterizable tropospheric correction.
VisibilityFromStationDetector(GeometricStationAntenna stationModel, AngularCorrection correctionModel, int slopeSelection, double maxCheck, double threshold, EventDetector.Action action, boolean remove, VisibilityFromStationDetector.LinkType linkTypeIn) Build a new apparent elevation detector with parameterizable tropospheric correction.
VisibilityFromStationDetector(GeometricStationAntenna stationModel, SensorModel sensorModel, AngularCorrection correctionModel, boolean withMasking, double maxCheck, double threshold, EventDetector.Action raising, EventDetector.Action setting, boolean removeRaising, boolean removeSetting, VisibilityFromStationDetector.LinkType linkTypeIn) Build a new apparent elevation detector with parameterizable tropospheric correction.
VisibilityFromStationDetector(TopocentricFrame topoFrame, double[][] azimElevMask, AngularCorrection correctionModel, double maxCheck, double threshold, EventDetector.Action raising, EventDetector.Action setting, boolean removeRaising, boolean removeSetting, VisibilityFromStationDetector.LinkType linkTypeIn) Build a new apparent elevation detector with parameterizable tropospheric correction.
VisibilityFromStationDetector(TopocentricFrame topoFrame, double[][] azimElevMask, AngularCorrection correctionModel, double maxCheck, double threshold, EventDetector.Action raising, EventDetector.Action setting, VisibilityFromStationDetector.LinkType linkTypeIn) Build a new apparent elevation detector with parameterizable tropospheric correction.
VisibilityFromStationDetector(TopocentricFrame topoFrame, double[][] azimElevMask, AngularCorrection correctionModel, double maxCheck, double threshold, VisibilityFromStationDetector.LinkType linkTypeIn) Build a new apparent elevation detector with parameterizable tropospheric correction.
VisibilityFromStationDetector(TopocentricFrame topoFrame, double[][] azimElevMask, SensorModel sensorModel, AngularCorrection correctionModel, boolean withMasking, double maxCheck, double threshold, EventDetector.Action raising, EventDetector.Action setting, boolean removeRaising, boolean removeSetting, VisibilityFromStationDetector.LinkType linkTypeIn) Build a new apparent elevation detector with parameterizable tropospheric correction.

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 "visibility from station" event and choose what to do next.
double	g(SpacecraftState state) Compute the value of the switching function.
BodyShape	getBodyShape() Getter for the body shape.
BodyPoint	getStationBodyPoint() Getter for the station body point.
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.

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

getAssembly, getCorrectedVector, getCorrection, getDatationChoice, getEmitter, getLinkType, getMinMaskingDistance, getReceiver, getSensor, getStation, getStationDate, isMaskingCheck

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

getEpsilonSignalPropagation, getInertialFrame, getMaxIterSignalPropagation, getPropagationDelayType, 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, shouldBeRemoved

Methods inherited from class java.lang.Object

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

Field Detail

RAISING

public static final int RAISING

Flag for raising detection (slopeSelection = 0).

See Also:

Constant Field Values

SETTING

public static final int SETTING

Flag for setting detection (slopeSelection = 1).

See Also:

Constant Field Values

RAISING_SETTING

public static final int RAISING_SETTING

Flag for raising/setting detection (slopeSelection = 2).

See Also:

Constant Field Values

Constructor Detail

VisibilityFromStationDetector

public VisibilityFromStationDetector(TopocentricFrame topoFrame,
                                     double[][] azimElevMask,
                                     AngularCorrection correctionModel,
                                     double maxCheck,
                                     double threshold,
                                     VisibilityFromStationDetector.LinkType linkTypeIn)

Build a new apparent elevation detector with parameterizable tropospheric correction.

The maximal interval between elevation checks should be smaller than the half duration of the minimal pass to handle, otherwise some short passes could be missed.

The default implementation behavior is to continue propagation at raising and to stop propagation at setting.

Parameters:

topoFrame - the station's topocentric frame

azimElevMask - the azimuth - elevation mask (rad)

correctionModel - the elevation correction model for the station (set null to ignore tropospheric correction)

maxCheck - maximal checking interval (s)

threshold - convergence threshold (s)

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

VisibilityFromStationDetector

public VisibilityFromStationDetector(TopocentricFrame topoFrame,
                                     double[][] azimElevMask,
                                     AngularCorrection correctionModel,
                                     double maxCheck,
                                     double threshold,
                                     EventDetector.Action raising,
                                     EventDetector.Action setting,
                                     VisibilityFromStationDetector.LinkType linkTypeIn)

Build a new apparent elevation detector with parameterizable tropospheric correction.

The maximal interval between elevation checks should be smaller than the half duration of the minimal pass to handle, otherwise some short passes could be missed.

Parameters:

topoFrame - the station's topocentric frame

azimElevMask - the azimuth - elevation mask (rad)

correctionModel - the elevation correction model for the station (set null to ignore tropospheric correction)

maxCheck - maximal checking interval (s)

threshold - convergence threshold (s)

raising - action performed when propagation at raising

setting - action performed when propagation at setting

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

VisibilityFromStationDetector

public VisibilityFromStationDetector(TopocentricFrame topoFrame,
                                     double[][] azimElevMask,
                                     AngularCorrection correctionModel,
                                     double maxCheck,
                                     double threshold,
                                     EventDetector.Action raising,
                                     EventDetector.Action setting,
                                     boolean removeRaising,
                                     boolean removeSetting,
                                     VisibilityFromStationDetector.LinkType linkTypeIn)

Build a new apparent elevation detector with parameterizable tropospheric correction.

The maximal interval between elevation checks should be smaller than the half duration of the minimal pass to handle, otherwise some short passes could be missed.

Parameters:

topoFrame - the station's topocentric frame

azimElevMask - the azimuth - elevation mask (rad)

correctionModel - the elevation correction model for the station (set null to ignore tropospheric correction)

maxCheck - maximal checking interval (s)

threshold - convergence threshold (s)

raising - action performed when propagation at raising

setting - action performed when propagation at setting

removeRaising - true if detector should be removed at raising

removeSetting - true if detector should be removed at setting

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

VisibilityFromStationDetector

public VisibilityFromStationDetector(TopocentricFrame topoFrame,
                                     double[][] azimElevMask,
                                     SensorModel sensorModel,
                                     AngularCorrection correctionModel,
                                     boolean withMasking,
                                     double maxCheck,
                                     double threshold,
                                     EventDetector.Action raising,
                                     EventDetector.Action setting,
                                     boolean removeRaising,
                                     boolean removeSetting,
                                     VisibilityFromStationDetector.LinkType linkTypeIn)

Build a new apparent elevation detector with parameterizable tropospheric correction.

The maximal interval between elevation checks should be smaller than the half duration of the minimal pass to handle, otherwise some short passes could be missed.

Parameters:

topoFrame - the station's topocentric frame

azimElevMask - the azimuth - elevation mask (rad)

sensorModel - sensor model of the spacecraft used for masking computations (not used otherwise, can be set to null). The sensor model of the main part frame of the assembly must have a parent frame! Make sure that the main target of this sensor model is the above station!

correctionModel - the elevation correction model for the station (set null to ignore tropospheric correction)

withMasking - set true to compute maskings of spacecraft's sensor by occulting bodies: in this case, there is no visibility if one of the masking bodies of the sensor is between the spacecraft and the station

maxCheck - maximal checking interval (s)

threshold - convergence threshold (s)

raising - action performed when propagation at raising

setting - action performed when propagation at setting

removeRaising - true if detector should be removed at raising

removeSetting - true if detector should be removed at setting

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

VisibilityFromStationDetector

public VisibilityFromStationDetector(GeometricStationAntenna stationModel,
                                     AngularCorrection correctionModel,
                                     double maxCheck,
                                     double threshold,
                                     VisibilityFromStationDetector.LinkType linkTypeIn)

Build a new apparent elevation detector with parameterizable tropospheric correction.

The maximal interval between elevation checks should be smaller than the half duration of the minimal pass to handle, otherwise some short passes could be missed.

The default implementation behavior is to continue propagation at raising and to stop propagation at setting.

Parameters:

stationModel - the station sensor geometric model

correctionModel - the elevation correction model for the station (set null to ignore tropospheric correction)

maxCheck - maximal checking interval (s)

threshold - convergence threshold (s)

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

VisibilityFromStationDetector

public VisibilityFromStationDetector(GeometricStationAntenna stationModel,
                                     AngularCorrection correctionModel,
                                     double maxCheck,
                                     double threshold,
                                     EventDetector.Action raising,
                                     EventDetector.Action setting,
                                     VisibilityFromStationDetector.LinkType linkTypeIn)

Build a new apparent elevation detector with parameterizable tropospheric correction.

The maximal interval between elevation checks should be smaller than the half duration of the minimal pass to handle, otherwise some short passes could be missed.

Parameters:

stationModel - the station sensor geometric model

correctionModel - the elevation correction model for the station (set null to ignore tropospheric correction)

maxCheck - maximal checking interval (s)

threshold - convergence threshold (s)

raising - action performed when propagation at raising

setting - action performed when propagation at setting

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

VisibilityFromStationDetector

public VisibilityFromStationDetector(GeometricStationAntenna stationModel,
                                     AngularCorrection correctionModel,
                                     double maxCheck,
                                     double threshold,
                                     EventDetector.Action raising,
                                     EventDetector.Action setting,
                                     boolean removeRaising,
                                     boolean removeSetting,
                                     VisibilityFromStationDetector.LinkType linkTypeIn)

Build a new apparent elevation detector with parameterizable tropospheric correction.

The maximal interval between elevation checks should be smaller than the half duration of the minimal pass to handle, otherwise some short passes could be missed.

Parameters:

stationModel - the station sensor geometric model

correctionModel - the elevation correction model for the station (set null to ignore tropospheric correction)

maxCheck - maximal checking interval (s)

threshold - convergence threshold (s)

raising - action performed when propagation at raising

setting - action performed when propagation at setting

removeRaising - true if detector should be removed at raising

removeSetting - true if detector should be removed at setting

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

VisibilityFromStationDetector

public VisibilityFromStationDetector(GeometricStationAntenna stationModel,
                                     SensorModel sensorModel,
                                     AngularCorrection correctionModel,
                                     boolean withMasking,
                                     double maxCheck,
                                     double threshold,
                                     EventDetector.Action raising,
                                     EventDetector.Action setting,
                                     boolean removeRaising,
                                     boolean removeSetting,
                                     VisibilityFromStationDetector.LinkType linkTypeIn)

Build a new apparent elevation detector with parameterizable tropospheric correction.

The maximal interval between elevation checks should be smaller than the half duration of the minimal pass to handle, otherwise some short passes could be missed.

Parameters:

stationModel - the station sensor geometric model

sensorModel - sensor model of the spacecraft used for masking computations (not used otherwise, can be set to null). The sensor model of the main part frame of the assembly must have a parent frame! Make sure that the main target of this sensor model is the above station!

correctionModel - the elevation correction model for the station (set null to ignore tropospheric correction)

withMasking - set true to compute maskings of spacecraft's sensor by occulting bodies: in this case, there is no visibility if one of the masking bodies of the sensor is between the spacecraft and the station

maxCheck - maximal checking interval (s)

threshold - convergence threshold (s)

raising - action performed when propagation at raising

setting - action performed when propagation at setting

removeRaising - true if detector should be removed at raising

removeSetting - true if detector should be removed at setting

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

VisibilityFromStationDetector

public VisibilityFromStationDetector(GeometricStationAntenna stationModel,
                                     AngularCorrection correctionModel,
                                     int slopeSelection,
                                     double maxCheck,
                                     double threshold,
                                     EventDetector.Action action,
                                     boolean remove,
                                     VisibilityFromStationDetector.LinkType linkTypeIn)

Build a new apparent elevation detector with parameterizable tropospheric correction.

The maximal interval between elevation checks should be smaller than the half duration of the minimal pass to handle, otherwise some short passes could be missed.

No occulting body check through this constructor.

Parameters:

stationModel - the station sensor geometric model

correctionModel - the elevation correction model for the station (set null to ignore tropospheric correction)

slopeSelection - slope selection

maxCheck - maximal checking interval (s)

threshold - convergence threshold (s)

action - action performed when propagation at raising/setting depending on slope selection

remove - true if detector should be removed at raising/setting depending on slope selection

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

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 "visibility from station" event and choose what to do next.

Specified by:

eventOccurred in interface EventDetector

Overrides:

eventOccurred in class AbstractDetector

Parameters:

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

increasing - if true, the value of the switching function increases when times increases around event

forward - if true, the integration variable (time) increases during integration

Returns:

the action performed when propagation raising or setting

Throws:

PatriusException - if some specific error occurs

g

public double g(SpacecraftState state)
         throws PatriusException

Compute the value of the switching function.

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 - state

Returns:

value of the switching function

Throws:

PatriusException - if some specific error occurs

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.

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:

• correction: AngularCorrection
• station: GeometricStationAntenna

Returns:

a copy of the detector.

getStationBodyPoint

public BodyPoint getStationBodyPoint()

Getter for the station body point.

Returns:

the station body point

getBodyShape

public BodyShape getBodyShape()

Getter for the body shape.

Returns:

the body shape