Package org.orekit.propagation.events

Class EventShifter

java.lang.Object

org.orekit.propagation.events.EventShifter

All Implemented Interfaces:

DetectorModifier, EventDetector

public class EventShifter
extends Object
implements DetectorModifier

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).

Author:

Luc Maisonobe

See Also:

Propagator.addEventDetector(EventDetector), EventDetector

Constructor Summary

Constructors

Constructor	Description
EventShifter(EventDetectionSettings detectionSettings, EventDetector detector, boolean useShiftedStates, double increasingTimeShift, double decreasingTimeShift)	Protected constructor with full parameters.
EventShifter(EventDetector detector, boolean useShiftedStates, double increasingTimeShift, double decreasingTimeShift)	Build a new instance.

Method Summary

Modifier and Type	Method	Description
double	g(SpacecraftState s)	Compute the value of the switching function.
double	getDecreasingTimeShift()	Get the decreasing events time shift.
EventDetectionSettings	getDetectionSettings()	Getter for the settings.
EventDetector	getDetector()	Get the detector for the raw unshifted event.
EventHandler	getHandler()	Get the handler.
double	getIncreasingTimeShift()	Get the increasing events time shift.
EventShifter	withDetectionSettings(EventDetectionSettings 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.DetectorModifier

dependsOnTimeOnly, finish, init, reset

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

getMaxCheckInterval, getMaxIterationCount, getThreshold

Constructor Detail

EventShifter

public EventShifter(EventDetector detector,
                    boolean useShiftedStates,
                    double increasingTimeShift,
                    double 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.

EventShifter

public EventShifter(EventDetectionSettings detectionSettings,
                    EventDetector detector,
                    boolean useShiftedStates,
                    double increasingTimeShift,
                    double decreasingTimeShift)

Protected constructor with full parameters.

This constructor is not public as users are expected to use the builder API with the various withXxx() methods to set up the instance in a readable manner without using a huge amount of 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 EventHandler getHandler()

Get the handler.

Specified by:

getHandler in interface DetectorModifier

Specified by:

getHandler in interface EventDetector

Returns:

event handler to call at event occurrences

getDetectionSettings

public EventDetectionSettings getDetectionSettings()

Getter for the settings.

Specified by:

getDetectionSettings in interface DetectorModifier

Specified by:

getDetectionSettings in interface EventDetector

Returns:

detection settings

getDetector

public EventDetector getDetector()

Get the detector for the raw unshifted event.

Specified by:

getDetector in interface DetectorModifier

Returns:

the detector for the raw unshifted event

Since:

11.1

getIncreasingTimeShift

public double getIncreasingTimeShift()

Get the increasing events time shift.

Returns:

increasing events time shift

getDecreasingTimeShift

public double getDecreasingTimeShift()

Get the decreasing events time shift.

Returns:

decreasing events time shift

g

public double g(SpacecraftState 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 DetectorModifier

Specified by:

g in interface EventDetector

Parameters:

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

Returns:

value of the switching function

withDetectionSettings

public EventShifter withDetectionSettings(EventDetectionSettings settings)

Builds a new instance from the input detection settings.

Parameters:

settings - event detection settings to be used

Returns:

a new detector