Package org.orekit.propagation.events

Class FieldEventShifter<T extends CalculusFieldElement<T>>

java.lang.Object

org.orekit.propagation.events.FieldEventShifter<T>

All Implemented Interfaces:

FieldDetectorModifier<T>, FieldEventDetector<T>

public class FieldEventShifter<T extends CalculusFieldElement<T>>
extends Object
implements FieldDetectorModifier<T>

Wrapper shifting events occurrences times.

This class wraps an event detector to slightly shift the events occurrences times. A typical use case is for handling operational delays before or after some physical event really occurs.

For example, the satellite attitude mode may be switched from sun pointed to spin-stabilized a few minutes before eclipse entry, and switched back to sun pointed a few minutes after eclipse exit. This behavior is handled by wrapping an eclipse detector into an instance of this class with a positive times shift for increasing events (eclipse exit) and a negative times shift for decreasing events (eclipse entry).

Since:

13.0

Author:

Luc Maisonobe, Romain Serra

See Also:

FieldPropagator.addEventDetector(FieldEventDetector), FieldEventDetector, EventShifter

Constructor Summary

Constructors

Constructor	Description
FieldEventShifter(FieldEventDetectionSettings<T> detectionSettings, FieldEventDetector<T> detector, boolean useShiftedStates, T increasingTimeShift, T decreasingTimeShift)	Constructor with full parameters.
FieldEventShifter(FieldEventDetector<T> detector, boolean useShiftedStates, T increasingTimeShift, T decreasingTimeShift)	Build a new instance.

Method Summary

Modifier and Type	Method	Description
T	g(FieldSpacecraftState<T> s)	Compute the value of the switching function.
T	getDecreasingTimeShift()	Get the decreasing events time shift.
FieldEventDetectionSettings<T>	getDetectionSettings()	Getter for the settings.
FieldEventDetector<T>	getDetector()	Get the detector for the raw unshifted event.
FieldEventHandler<T>	getHandler()	Get the handler.
T	getIncreasingTimeShift()	Get the increasing events time shift.
FieldEventShifter<T>	withDetectionSettings(FieldEventDetectionSettings<T> settings)	Builds a new instance from the input detection settings.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.orekit.propagation.events.FieldDetectorModifier

dependsOnMainVariablesOnly, dependsOnTimeOnly, finish, init, reset

Methods inherited from interface org.orekit.propagation.events.FieldEventDetector

getMaxCheckInterval, getMaxIterationCount, getThreshold

Constructor Detail

FieldEventShifter

public FieldEventShifter(FieldEventDetector<T> detector,
                         boolean useShiftedStates,
                         T increasingTimeShift,
                         T decreasingTimeShift)

Build a new instance.

The max check interval, the convergence threshold of the raw unshifted events will be used for the shifted event. When an event occurs, the eventOccurred method of the raw unshifted events will be called (with spacecraft state at either the shifted or the unshifted event date depending on the useShiftedStates parameter).

Parameters:

detector - event detector for the raw unshifted event

useShiftedStates - if true, the state provided to eventOccurred method of the associated handler will remain shifted, otherwise it will be unshifted to correspond to the underlying raw event.

increasingTimeShift - increasing events time shift.

decreasingTimeShift - decreasing events time shift.

FieldEventShifter

public FieldEventShifter(FieldEventDetectionSettings<T> detectionSettings,
                         FieldEventDetector<T> detector,
                         boolean useShiftedStates,
                         T increasingTimeShift,
                         T decreasingTimeShift)

Constructor with full parameters.

Parameters:

detectionSettings - event detection settings

detector - event detector for the raw unshifted event

useShiftedStates - if true, the state provided to eventOccurred method of the detector will remain shifted, otherwise it will be unshifted to correspond to the underlying raw event.

increasingTimeShift - increasing events time shift.

decreasingTimeShift - decreasing events time shift.

Since:

13.0

Method Detail

getHandler

public FieldEventHandler<T> getHandler()

Description copied from interface: FieldDetectorModifier

Get the handler.

Specified by:

getHandler in interface FieldDetectorModifier<T extends CalculusFieldElement<T>>

Specified by:

getHandler in interface FieldEventDetector<T extends CalculusFieldElement<T>>

Returns:

event handler to call at event occurrences

getDetectionSettings

public FieldEventDetectionSettings<T> getDetectionSettings()

Description copied from interface: FieldDetectorModifier

Getter for the settings.

Specified by:

getDetectionSettings in interface FieldDetectorModifier<T extends CalculusFieldElement<T>>

Specified by:

getDetectionSettings in interface FieldEventDetector<T extends CalculusFieldElement<T>>

Returns:

detection settings

getDetector

public FieldEventDetector<T> getDetector()

Get the detector for the raw unshifted event.

Specified by:

getDetector in interface FieldDetectorModifier<T extends CalculusFieldElement<T>>

Returns:

the detector for the raw unshifted event

getIncreasingTimeShift

public T getIncreasingTimeShift()

Get the increasing events time shift.

Returns:

increasing events time shift

getDecreasingTimeShift

public T getDecreasingTimeShift()

Get the decreasing events time shift.

Returns:

decreasing events time shift

withDetectionSettings

public FieldEventShifter<T> withDetectionSettings(FieldEventDetectionSettings<T> settings)

Builds a new instance from the input detection settings.

Parameters:

settings - event detection settings to be used

Returns:

a new detector

g

public T g(FieldSpacecraftState<T> s)

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 FieldDetectorModifier<T extends CalculusFieldElement<T>>

Specified by:

g in interface FieldEventDetector<T extends CalculusFieldElement<T>>

Parameters:

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

Returns:

value of the switching function