Package org.orekit.propagation.events

Class FieldLongitudeCrossingDetector<T extends CalculusFieldElement<T>>

java.lang.Object

org.orekit.propagation.events.FieldAbstractDetector<FieldLongitudeCrossingDetector<T>,T>

org.orekit.propagation.events.FieldAbstractGeographicalDetector<FieldLongitudeCrossingDetector<T>,T>

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

Type Parameters:

T - type of the field elements

All Implemented Interfaces:

FieldDetectorModifier<T>, FieldEventDetector<T>

public class FieldLongitudeCrossingDetector<T extends CalculusFieldElement<T>>
extends FieldAbstractGeographicalDetector<FieldLongitudeCrossingDetector<T>,T>
implements FieldDetectorModifier<T>

Detector for geographic longitude crossing.

This detector identifies when a spacecraft crosses a fixed longitude with respect to a central body.

The value is the longitude difference between the spacecraft and the fixed longitude to be crossed, with some sign tweaks to ensure continuity. These tweaks imply the increasing flag in events detection becomes irrelevant here! As an example, the longitude of a prograde spacecraft will always increase, but this g function will increase and decrease so it will cross the zero value once per orbit, in increasing and decreasing directions on alternate orbits. If eastwards and westwards crossing have to be distinguished, the velocity direction has to be checked instead of looking at the increasing flag.

Since:

12.0

Author:

Alberto Ferrero

Field Summary

Fields inherited from class org.orekit.propagation.events.FieldAbstractDetector

DEFAULT_MAX_CHECK, DEFAULT_MAX_ITER, DEFAULT_THRESHOLD

Constructor Summary

Constructors

Modifier	Constructor	Description
	FieldLongitudeCrossingDetector(Field<T> field, BodyShape body, double longitude)	Build a new detector.
protected	FieldLongitudeCrossingDetector(FieldEventDetectionSettings<T> detectionSettings, FieldEventHandler<T> handler, BodyShape body, double longitude)	Protected constructor with full parameters.
	FieldLongitudeCrossingDetector(T maxCheck, T threshold, BodyShape body, double longitude)	Build a detector.

Method Summary

Modifier and Type	Method	Description
protected FieldLongitudeCrossingDetector<T>	create(FieldEventDetectionSettings<T> detectionSettings, FieldEventHandler<T> newHandler)	Build a new instance.
FieldEventDetector<T>	getDetector()	Getter for wrapped detector.
EventFunction	getEventFunction()	Get the event function.
double	getLongitude()	Get the fixed longitude to be crossed (radians).
void	init(FieldSpacecraftState<T> s0, FieldAbsoluteDate<T> t)	Initialize event detector at the start of a propagation.
LongitudeCrossingDetector	toEventDetector(EventHandler eventHandler)	Build non-Field instance.

Methods inherited from class org.orekit.propagation.events.FieldAbstractGeographicalDetector

getBodyShape

Methods inherited from class org.orekit.propagation.events.FieldAbstractDetector

checkIfForward, getDetectionSettings, getHandler, isForward, withDetectionSettings, withHandler, withMaxCheck, withMaxCheck, withMaxIter, withThreshold

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

finish, g, getDetectionSettings, getHandler, reset

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

getMaxCheckInterval, getMaxIterationCount, getThreshold

Constructor Details

FieldLongitudeCrossingDetector

public FieldLongitudeCrossingDetector(Field<T> field,
 BodyShape body,
 double longitude)

Build a new detector.

The new instance uses default values for maximal checking interval (FieldAbstractDetector.DEFAULT_MAX_CHECK) and convergence threshold (FieldAbstractDetector.DEFAULT_THRESHOLD).

Parameters:

field - the type of numbers to use.

body - body on which the longitude is defined

longitude - longitude to be crossed

FieldLongitudeCrossingDetector

public FieldLongitudeCrossingDetector(T maxCheck,
 T threshold,
 BodyShape body,
 double longitude)

Build a detector.

Parameters:

maxCheck - maximal checking interval (s)

threshold - convergence threshold (s)

body - body on which the longitude is defined

longitude - longitude to be crossed

FieldLongitudeCrossingDetector

protected FieldLongitudeCrossingDetector(FieldEventDetectionSettings<T> detectionSettings,
 FieldEventHandler<T> handler,
 BodyShape body,
 double longitude)

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

handler - event handler to call at event occurrences

body - body on which the longitude is defined

longitude - longitude to be crossed

Method Details

create

protected FieldLongitudeCrossingDetector<T> create(FieldEventDetectionSettings<T> detectionSettings,
 FieldEventHandler<T> newHandler)

Build a new instance.

Specified by:

create in class FieldAbstractDetector<FieldLongitudeCrossingDetector<T extends CalculusFieldElement<T>>,T extends CalculusFieldElement<T>>

Parameters:

detectionSettings - detection settings

newHandler - event handler to call at event occurrences

Returns:

a new instance of the appropriate sub-type

getEventFunction

public EventFunction getEventFunction()

Description copied from interface: FieldEventDetector

Get the event function. It defines g both for double and Field.

Specified by:

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

Specified by:

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

Overrides:

getEventFunction in class FieldAbstractDetector<FieldLongitudeCrossingDetector<T extends CalculusFieldElement<T>>,T extends CalculusFieldElement<T>>

Returns:

event function

getLongitude

public double getLongitude()

Get the fixed longitude to be crossed (radians).

Returns:

fixed longitude to be crossed (radians)

init

public void init(FieldSpacecraftState<T> s0,
 FieldAbsoluteDate<T> t)

Initialize event detector at the start of a propagation.

This method is called once at the start of the propagation. It may be used by the event detector to initialize some internal data if needed.

The default implementation initializes the handler.

Specified by:

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

Specified by:

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

Overrides:

init in class FieldAbstractDetector<FieldLongitudeCrossingDetector<T extends CalculusFieldElement<T>>,T extends CalculusFieldElement<T>>

Parameters:

s0 - initial state

t - target time for the integration

getDetector

public FieldEventDetector<T> getDetector()

Description copied from interface: FieldDetectorModifier

Getter for wrapped detector.

Specified by:

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

Returns:

detector

toEventDetector

public LongitudeCrossingDetector toEventDetector(EventHandler eventHandler)

Build non-Field instance.

Overrides:

toEventDetector in class FieldAbstractDetector<FieldLongitudeCrossingDetector<T extends CalculusFieldElement<T>>,T extends CalculusFieldElement<T>>

Parameters:

eventHandler - event handler

Returns:

event detector