fr.cnes.sirius.patrius.events.detectors

Class LocalTimeAngleDetector

java.lang.Object

fr.cnes.sirius.patrius.events.AbstractDetector

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

fr.cnes.sirius.patrius.events.detectors.LocalTimeAngleDetector

All Implemented Interfaces:

EventDetector, Serializable

Direct Known Subclasses:

BodyPointLocalTimeAngleDetector

public class LocalTimeAngleDetector
extends AbstractSignalPropagationDetector

Detects when the local time angle of a spacecraft is equal to a predetermined value.
The local time is represented by the angle between the projections of the Sun and the satellite in the equatorial plane; therefore this angle is equal to zero when the local time is 12.00h and Π when the local time is 0.00h (Local Time In Hours = 12.00h + local time angle * 12 / Π).

The default implementation is to stop propagation when the local time is reached. This can be changed by using 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: LocalTimeAngleDetector.java 17582 2017-05-10 12:58:16Z bignon $

Author:

Tiziana Sabatini

See Also:

EventDetector, Serialized Form

Concurrency :

not thread-safe

Concurrency comment :

attributes are mutable and related to propagation.

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
LocalTimeAngleDetector(double localTimeAngle) Constructor for a LocalTimeDetector instance.
LocalTimeAngleDetector(double localTimeAngle, double maxCheck, double threshold) Constructor for a LocalTimeDetector instance with complimentary parameters.
LocalTimeAngleDetector(double localTimeAngle, double maxCheck, double threshold, CelestialBodyFrame frame) Constructor for a LocalTimeDetector instance with complimentary parameters.
LocalTimeAngleDetector(double localTimeAngle, double maxCheck, double threshold, CelestialBodyFrame frame, EventDetector.Action action) Constructor for a LocalTimeDetector instance with complimentary parameters.
LocalTimeAngleDetector(double localTimeAngle, double maxCheck, double threshold, CelestialBodyFrame frame, EventDetector.Action action, boolean remove) Constructor for a LocalTimeDetector instance with complimentary parameters.
LocalTimeAngleDetector(double localTimeAngle, double maxCheck, double threshold, CelestialBodyFrame frame, EventDetector.Action action, boolean remove, PVCoordinatesProvider sun) Constructor for a LocalTimeDetector instance with complimentary parameters including Sun choice.
LocalTimeAngleDetector(double localTimeAngle, double maxCheck, double threshold, CelestialBodyFrame frame, EventDetector.Action action, boolean remove, PVCoordinatesProvider sun, int slopeSelection) Constructor for a LocalTimeDetector instance with complimentary parameters including Sun choice.
LocalTimeAngleDetector(double localTimeAngle, double maxCheck, double threshold, EventDetector.Action action) Constructor for a LocalTimeDetector instance with complimentary parameters.
LocalTimeAngleDetector(double localTimeAngle, double maxCheck, double threshold, EventDetector.Action action, boolean remove) Constructor for a LocalTimeDetector instance with complimentary parameters.
LocalTimeAngleDetector(double localTimeAngle, double maxCheck, double threshold, EventDetector.Action action, boolean remove, PVCoordinatesProvider sun) Constructor for a LocalTimeDetector instance with complimentary parameters including Sun choice.

Method Summary

Modifier and Type	Method and Description
protected double	computeLocalTime(SpacecraftState state) Compute the local time.
protected double	computeSunSatAngle(Vector3D satPos, Vector3D sunPos) Compute the angle between the sun and the satellite projections over the equatiorial plane
EventDetector	copy() A copy of the detector.
EventDetector.Action	eventOccurred(SpacecraftState s, boolean increasing, boolean forward) Handle a local time angle event and choose what to do next.
boolean	filterEvent(SpacecraftState state, boolean increasing, boolean forward) Filter last event: returns true if the last event is a false detection, false otherwise.
double	g(SpacecraftState state) Compute the value of the switching function.
EventDetector.Action	getAction() Return the action at detection.
CelestialBodyFrame	getFrame() Returns the frame used for solar time computation.
PVCoordinatesProvider	getSun() Return the sun
double	getTime() Get local time angle to detect.
void	init(SpacecraftState s0, AbsoluteDate t) Initialize event handler at the start of a propagation.

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, setPropagationDelayType

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

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

Constructor Detail

LocalTimeAngleDetector

public LocalTimeAngleDetector(double localTimeAngle)
                       throws PatriusException

Constructor for a LocalTimeDetector instance.

Local time will be computed in satellite orbit frame.

Parameters:

localTimeAngle - satellite local time angle triggering the event (in the range [-Π, Π[). Angle between the projections of the Sun and the satellite in the equatorial plane (Local Time In Hours = 12.00h + localTimeAngle * 12 / Π)

Throws:

PatriusException - error when loading the ephemeris files or local time angle not in the range [-Π, Π[

LocalTimeAngleDetector

public LocalTimeAngleDetector(double localTimeAngle,
                              double maxCheck,
                              double threshold)
                       throws PatriusException

Constructor for a LocalTimeDetector instance with complimentary parameters.

The default implementation behavior is to stop propagation when the local time is reached.

Local time will be computed in satellite orbit frame.

Parameters:

localTimeAngle - satellite local time angle triggering the event (in the range [-Π, Π[). Angle between the projections of the Sun and the satellite in the equatorial plane (Local Time In Hours = 12.00h + localTimeAngle * 12 / Π)

maxCheck - maximum check (see AbstractDetector)

threshold - threshold (see AbstractDetector)

Throws:

PatriusException - error when loading the ephemeris files or local time angle not in the range [-Π, Π[

LocalTimeAngleDetector

public LocalTimeAngleDetector(double localTimeAngle,
                              double maxCheck,
                              double threshold,
                              CelestialBodyFrame frame)
                       throws PatriusException

Constructor for a LocalTimeDetector instance with complimentary parameters.

The default implementation behavior is to stop propagation when the local time is reached.

Parameters:

localTimeAngle - satellite local time angle triggering the event (in the range [-Π, Π[). Angle between the projections of the Sun and the satellite in the equatorial plane (Local Time In Hours = 12.00h + localTimeAngle * 12 / Π)

maxCheck - maximum check (see AbstractDetector)

threshold - threshold (see AbstractDetector)

frame - in relation to which the calculations are made

Throws:

PatriusException - error when loading the ephemeris files or local time angle not in the range [-Π, Π[ or frame not null and not inertial

LocalTimeAngleDetector

public LocalTimeAngleDetector(double localTimeAngle,
                              double maxCheck,
                              double threshold,
                              EventDetector.Action action)
                       throws PatriusException

Constructor for a LocalTimeDetector instance with complimentary parameters.

Local time will be computed in satellite orbit frame.

Parameters:

localTimeAngle - satellite local time angle triggering the event (in the range [-Π, Π[). Angle between the projections of the Sun and the satellite in the equatorial plane (Local Time In Hours = 12.00h + localTimeAngle * 12 / Π)

maxCheck - maximum check (see AbstractDetector)

threshold - threshold (see AbstractDetector)

action - action performed at local time detection

Throws:

PatriusException - error when loading the ephemeris files or local time angle not in the range [-Π, Π[

LocalTimeAngleDetector

public LocalTimeAngleDetector(double localTimeAngle,
                              double maxCheck,
                              double threshold,
                              CelestialBodyFrame frame,
                              EventDetector.Action action)
                       throws PatriusException

Constructor for a LocalTimeDetector instance with complimentary parameters.

Parameters:

localTimeAngle - satellite local time angle triggering the event (in the range [-Π, Π[). Angle between the projections of the Sun and the satellite in the equatorial plane (Local Time In Hours = 12.00h + localTimeAngle * 12 / Π)

maxCheck - maximum check (see AbstractDetector)

threshold - threshold (see AbstractDetector)

action - action performed at local time detection

frame - in relation to which the calculations are made

Throws:

PatriusException - error when loading the ephemeris files or local time angle not in the range [-Π, Π[ or frame not null and not inertial

LocalTimeAngleDetector

public LocalTimeAngleDetector(double localTimeAngle,
                              double maxCheck,
                              double threshold,
                              EventDetector.Action action,
                              boolean remove)
                       throws PatriusException

Constructor for a LocalTimeDetector instance with complimentary parameters.

Local time will be computed in satellite orbit frame.

Parameters:

localTimeAngle - satellite local time angle triggering the event (in the range [-Π, Π[). Angle between the projections of the Sun and the satellite in the equatorial plane (Local Time In Hours = 12.00h + localTimeAngle * 12 / Π)

maxCheck - maximum check (see AbstractDetector)

threshold - threshold (see AbstractDetector)

action - action performed at local time detection

remove - true if detector should be removed

Throws:

PatriusException - error when loading the ephemeris files or local time angle not in the range [-Π, Π[

Since:

3.1

LocalTimeAngleDetector

public LocalTimeAngleDetector(double localTimeAngle,
                              double maxCheck,
                              double threshold,
                              CelestialBodyFrame frame,
                              EventDetector.Action action,
                              boolean remove)
                       throws PatriusException

Constructor for a LocalTimeDetector instance with complimentary parameters.

Parameters:

localTimeAngle - satellite local time angle triggering the event (in the range [-Π, Π[). Angle between the projections of the Sun and the satellite in the equatorial plane (Local Time In Hours = 12.00h + localTimeAngle * 12 / Π)

maxCheck - maximum check (see AbstractDetector)

threshold - threshold (see AbstractDetector)

action - action performed at local time detection

remove - true if detector should be removed

frame - in relation to which the calculations are made

Throws:

PatriusException - error when loading the ephemeris files or local time angle not in the range [-Π, Π[ or frame not null and not inertial

Since:

3.1

LocalTimeAngleDetector

public LocalTimeAngleDetector(double localTimeAngle,
                              double maxCheck,
                              double threshold,
                              EventDetector.Action action,
                              boolean remove,
                              PVCoordinatesProvider sun)
                       throws PatriusException

Constructor for a LocalTimeDetector instance with complimentary parameters including Sun choice.

Local time will be computed in satellite orbit frame.

Parameters:

localTimeAngle - satellite local time angle triggering the event (in the range [-Π, Π[). Angle between the projections of the Sun and the satellite in the equatorial plane (Local Time In Hours = 12.00h + localTimeAngle * 12 / Π)

maxCheck - maximum check (see AbstractDetector)

threshold - threshold (see AbstractDetector)

action - action performed at local time detection

remove - true if detector should be removed

sun - Sun

Throws:

PatriusException - error when loading the ephemeris files or local time angle not in the range [-Π, Π[

Since:

4.5

LocalTimeAngleDetector

public LocalTimeAngleDetector(double localTimeAngle,
                              double maxCheck,
                              double threshold,
                              CelestialBodyFrame frame,
                              EventDetector.Action action,
                              boolean remove,
                              PVCoordinatesProvider sun)
                       throws PatriusException

Constructor for a LocalTimeDetector instance with complimentary parameters including Sun choice.

Parameters:

localTimeAngle - satellite local time angle triggering the event (in the range [-Π, Π[). Angle between the projections of the Sun and the satellite in the equatorial plane (Local Time In Hours = 12.00h + localTimeAngle * 12 / Π)

maxCheck - maximum check (see AbstractDetector)

threshold - threshold (see AbstractDetector)

action - action performed at local time detection

remove - true if detector should be removed

sun - Sun

frame - in relation to which the calculations are made

Throws:

PatriusException - error when loading the ephemeris files or local time angle not in the range [-Π, Π[ or frame not null and not inertial

Since:

4.5

LocalTimeAngleDetector

public LocalTimeAngleDetector(double localTimeAngle,
                              double maxCheck,
                              double threshold,
                              CelestialBodyFrame frame,
                              EventDetector.Action action,
                              boolean remove,
                              PVCoordinatesProvider sun,
                              int slopeSelection)
                       throws PatriusException

Constructor for a LocalTimeDetector instance with complimentary parameters including Sun choice.

Parameters:

localTimeAngle - satellite local time angle triggering the event (in the range [-Π, Π[). Angle between the projections of the Sun and the satellite in the equatorial plane (Local Time In Hours = 12.00h + localTimeAngle * 12 / Π)

maxCheck - maximum check (see AbstractDetector)

threshold - threshold (see AbstractDetector)

action - action performed at local time detection

remove - true if detector should be removed

sun - Sun

frame - in relation to which the calculations are made

slopeSelection - NodeDetector.ASCENDING for ascending node detection,
NodeDetector.DESCENDING for descending node detection,
NodeDetector.ASCENDING_DESCENDING for both ascending and descending node detection.

Throws:

PatriusException - error when loading the ephemeris files or local time angle not in the range [-Π, Π[ or frame not null and not inertial

Since:

4.5

Method Detail

eventOccurred

public EventDetector.Action eventOccurred(SpacecraftState s,
                                          boolean increasing,
                                          boolean forward)
                                   throws PatriusException

Handle a local time angle 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 time increases around event

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

Returns:

the action performed when the expected local time is reached

Throws:

PatriusException - if some specific error occurs

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.

Specified by:

g in interface EventDetector

Specified by:

g in class AbstractDetector

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

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

filterEvent

public boolean filterEvent(SpacecraftState state,
                           boolean increasing,
                           boolean forward)
                    throws PatriusException

Filter last event: returns true if the last event is a false detection, false otherwise.

This method is called right before EventDetector.eventOccurred(SpacecraftState, boolean, boolean) method.

This may be useful in order to filter some events in particular when angles are at stake (see for example LocalTimeAngleDetector).

Specified by:

filterEvent in interface EventDetector

Overrides:

filterEvent in class AbstractDetector

Parameters:

state - state at last event occurrence

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:

true if the last event is a false detection, false otherwise

Throws:

PatriusException - thrown if computation failed for some reasons

computeLocalTime

protected double computeLocalTime(SpacecraftState state)
                           throws PatriusException

Compute the local time.

Parameters:

state - current state

Returns:

local time

Throws:

PatriusException - thrown if computation failed

computeSunSatAngle

protected double computeSunSatAngle(Vector3D satPos,
                                    Vector3D sunPos)

Compute the angle between the sun and the satellite projections over the equatiorial plane

Parameters:

satPos - satellite position

sunPos - sun position

Returns:

the angle between the sun and the satellite

getTime

public double getTime()

Get local time angle to detect.

Returns:

the local time angle triggering the event (in the range [-&Pi, &Pi[).

Since:

1.2

getAction

public EventDetector.Action getAction()

Return the action at detection.

Returns:

action at detection

getFrame

public CelestialBodyFrame getFrame()

Returns the frame used for solar time computation.

Returns:

the frame used for solar time computation

getSun

public PVCoordinatesProvider getSun()

Return the sun

Returns:

the sun

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.

Returns:

a copy of the detector.