fr.cnes.sirius.patrius.events.detectors

Class BetaAngleDetector

java.lang.Object

fr.cnes.sirius.patrius.events.AbstractDetector

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

fr.cnes.sirius.patrius.events.detectors.BetaAngleDetector

All Implemented Interfaces:

EventDetector, Serializable

public class BetaAngleDetector
extends AbstractSignalPropagationDetector

Detects when the beta angle of the spacecraft reaches a predetermined value.
The beta angle is the angle between the orbit plane and the vector from the central body to the sun. The angle is positive on the side of the plane containing the spacecraft's momentum vector. The bodies considered are :

• the spacecraft
• the central body for the spacecraft
• the Sun

The default implementation behaviour is to EventDetector.Action#STOP stop propagation when the beta angle 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: BetaAngleDetector.java 17582 2017-05-10 12:58:16Z bignon $

Author:

cardosop

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
BetaAngleDetector(double ang) Constructor for a BetaAngleDetector instance.
BetaAngleDetector(double ang, double maxCheck, double threshold) Constructor for a BetaAngleDetector instance with complimentary parameters.
BetaAngleDetector(double ang, double maxCheck, double threshold, EventDetector.Action action) Constructor for a BetaAngleDetector instance with complimentary parameters.
BetaAngleDetector(double ang, double maxCheck, double threshold, EventDetector.Action action, boolean remove) Constructor for a BetaAngleDetector instance with complimentary parameters.
BetaAngleDetector(double ang, double maxCheck, double threshold, EventDetector.Action action, boolean remove, PVCoordinatesProvider sun) Constructor for a BetaAngleDetector instance with complimentary parameters including Sun choice.

Method Summary

Modifier and Type	Method and Description
EventDetector	copy() A copy of the detector.
EventDetector.Action	eventOccurred(SpacecraftState s, boolean increasing, boolean forward) Handles a beta angle event and chooses what to do next.
double	g(SpacecraftState state) Compute the value of the switching function.
double	getAngle() Returns beta angle triggering the event.
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.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, shouldBeRemoved

Methods inherited from class java.lang.Object

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

Constructor Detail

BetaAngleDetector

public BetaAngleDetector(double ang)
                  throws PatriusException

Constructor for a BetaAngleDetector instance.

Parameters:

ang - angle in radians triggering the event.

Throws:

PatriusException - thrown if Sun could not be retrieved

BetaAngleDetector

public BetaAngleDetector(double ang,
                         double maxCheck,
                         double threshold)
                  throws PatriusException

Constructor for a BetaAngleDetector instance with complimentary parameters.

The default implementation behavior is to EventDetector.Action#STOP stop propagation when the angle is reached.

Parameters:

ang - angle in radians triggering the event.

maxCheck - maximum check (see AbstractDetector)

threshold - threshold (see AbstractDetector)

Throws:

PatriusException - thrown if Sun could not be retrieved

IllegalArgumentException - if angle is out of range [-Pi / 2 , Pi / 2]

BetaAngleDetector

public BetaAngleDetector(double ang,
                         double maxCheck,
                         double threshold,
                         EventDetector.Action action)
                  throws PatriusException

Constructor for a BetaAngleDetector instance with complimentary parameters.

Parameters:

ang - angle in radians triggering the event.

maxCheck - maximum check (see AbstractDetector)

threshold - threshold (see AbstractDetector)

action - action performed at beta angle detection

Throws:

PatriusException - thrown if Sun could not be retrieved

IllegalArgumentException - if angle is out of range [-Pi / 2 , Pi / 2]

BetaAngleDetector

public BetaAngleDetector(double ang,
                         double maxCheck,
                         double threshold,
                         EventDetector.Action action,
                         boolean remove)
                  throws PatriusException

Constructor for a BetaAngleDetector instance with complimentary parameters.

Parameters:

ang - angle in radians triggering the event.

maxCheck - maximum check (see AbstractDetector)

threshold - threshold (see AbstractDetector)

action - action performed at beta angle detection

remove - if the detector should be removed

Throws:

PatriusException - thrown if Sun could not be retrieved

IllegalArgumentException - if angle is out of range [-Pi / 2 , Pi / 2]

Since:

3.1

BetaAngleDetector

public BetaAngleDetector(double ang,
                         double maxCheck,
                         double threshold,
                         EventDetector.Action action,
                         boolean remove,
                         PVCoordinatesProvider sun)

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

Parameters:

ang - angle in radians triggering the event.

maxCheck - maximum check (see AbstractDetector)

threshold - threshold (see AbstractDetector)

action - action performed at beta angle detection

remove - if the detector should be removed

sun - sun

Throws:

IllegalArgumentException - if angle is out of range [-Pi / 2 , Pi / 2]

Since:

4.5

Method Detail

eventOccurred

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

Handles a beta angle event and chooses 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:

performed the action when the angle 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

getAngle

public double getAngle()

Returns beta angle triggering the event.

Returns:

the Angle triggering the event.

setPropagationDelayType

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

Description copied from class: AbstractSignalPropagationDetector

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:

• sun: CelestialPoint

Returns:

a copy of the detector.