Package org.orekit.propagation.events

Class FieldBetaAngleDetector<T extends CalculusFieldElement<T>>

java.lang.Object

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

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

Type Parameters:

T - The field type

All Implemented Interfaces:

FieldEventDetector<T>

public class FieldBetaAngleDetector<T extends CalculusFieldElement<T>>
extends FieldAbstractDetector<FieldBetaAngleDetector<T>,T>

Finder for beta angle crossing events.

Locate events when the beta angle (the angle between the orbit plane and the celestial body) crosses a threshold. The g(FieldSpacecraftState) function is negative when the beta angle is above the threshold and positive when the beta angle is below the threshold.

The inertial frame provided must have it's origin centered at the satellite's orbit plane. The beta angle is computed as the angle between the celestial body's position in this frame with the satellite's orbital momentum vector.

The default implementation behavior is to stop propagation at the first event date occurrence. This can be changed by calling FieldAbstractDetector.withHandler(FieldEventHandler) after construction.

Since:

12.1

Author:

Joe Reed

See Also:

Propagator.addEventDetector(EventDetector)

Field Summary

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

DEFAULT_MAX_ITER, DEFAULT_MAXCHECK, DEFAULT_THRESHOLD

Constructor Summary

Constructors

Modifier	Constructor	Description
	FieldBetaAngleDetector(Field<T> field, T betaAngleThreshold, FieldPVCoordinatesProvider<T> celestialBodyProvider, Frame inertialFrame)	Class constructor.
protected	FieldBetaAngleDetector(FieldAdaptableInterval<T> maxCheck, T threshold, int maxIter, FieldEventHandler<T> handler, T betaAngleThreshold, FieldPVCoordinatesProvider<T> celestialBodyProvider, Frame inertialFrame)	Protected constructor with full parameters.
	FieldBetaAngleDetector(T betaAngleThreshold)	Solar beta angle constructor.

Method Summary

Modifier and Type	Method	Description
static <T extends CalculusFieldElement<T>> T	calculateBetaAngle(FieldSpacecraftState<T> state, FieldPVCoordinatesProvider<T> celestialBodyProvider)	Calculate the beta angle between the orbit plane and the celestial body.
static <T extends CalculusFieldElement<T>> T	calculateBetaAngle(FieldSpacecraftState<T> state, FieldPVCoordinatesProvider<T> celestialBodyProvider, Frame frame)	Calculate the beta angle between the orbit plane and the celestial body.
protected FieldBetaAngleDetector<T>	create(FieldAdaptableInterval<T> newMaxCheck, T newThreshold, int newMaxIter, FieldEventHandler<T> newHandler)	Build a new instance.
T	g(FieldSpacecraftState<T> s)	Compute the value of the switching function.
T	getBetaAngleThreshold()	The beta angle threshold (radians).
FieldPVCoordinatesProvider<T>	getCelestialBodyProvider()	Coordinate provider for the celestial body.
Frame	getInertialFrame()	The inertial frame in which beta angle is computed.
FieldBetaAngleDetector<T>	withBetaThreshold(T newBetaAngleThreshold)	Create a new instance with the provided beta angle threshold.
FieldBetaAngleDetector<T>	withCelestialProvider(FieldPVCoordinatesProvider<T> newProvider)	Create a new instance with the provided coordinate provider.
FieldBetaAngleDetector<T>	withInertialFrame(Frame newFrame)	Create a new instance with the provided inertial frame.

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

getHandler, getMaxCheckInterval, getMaxIterationCount, getThreshold, init, isForward, withHandler, withMaxCheck, withMaxCheck, withMaxIter, withThreshold

Methods inherited from class java.lang.Object

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

Constructor Detail

FieldBetaAngleDetector

@DefaultDataContext
public FieldBetaAngleDetector(T betaAngleThreshold)

Solar beta angle constructor.

This method uses the default data context, assigns the sun as the celestial body and uses GCRF as the inertial frame.

Parameters:

betaAngleThreshold - beta angle threshold (radians)

FieldBetaAngleDetector

public FieldBetaAngleDetector(Field<T> field,
                              T betaAngleThreshold,
                              FieldPVCoordinatesProvider<T> celestialBodyProvider,
                              Frame inertialFrame)

Class constructor.

Parameters:

field - the field instance

betaAngleThreshold - beta angle threshold (radians)

celestialBodyProvider - coordinate provider for the celestial provider

inertialFrame - inertial frame in which to compute the beta angle

FieldBetaAngleDetector

protected FieldBetaAngleDetector(FieldAdaptableInterval<T> maxCheck,
                                 T threshold,
                                 int maxIter,
                                 FieldEventHandler<T> handler,
                                 T betaAngleThreshold,
                                 FieldPVCoordinatesProvider<T> celestialBodyProvider,
                                 Frame inertialFrame)

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:

maxCheck - maximum checking interval

threshold - convergence threshold (s)

maxIter - maximum number of iterations in the event time search

handler - event handler to call at event occurrences

betaAngleThreshold - beta angle threshold (radians)

celestialBodyProvider - coordinate provider for the celestial provider

inertialFrame - inertial frame in which to compute the beta angle

Method Detail

getCelestialBodyProvider

public FieldPVCoordinatesProvider<T> getCelestialBodyProvider()

Coordinate provider for the celestial body.

Returns:

celestial body's coordinate provider

getInertialFrame

public Frame getInertialFrame()

The inertial frame in which beta angle is computed.

Returns:

the inertial frame

getBetaAngleThreshold

public T getBetaAngleThreshold()

The beta angle threshold (radians).

Returns:

the beta angle threshold (radians)

withCelestialProvider

public FieldBetaAngleDetector<T> withCelestialProvider(FieldPVCoordinatesProvider<T> newProvider)

Create a new instance with the provided coordinate provider.

This method does not change the current instance.

Parameters:

newProvider - the new coordinate provider

Returns:

the new detector instance

withBetaThreshold

public FieldBetaAngleDetector<T> withBetaThreshold(T newBetaAngleThreshold)

Create a new instance with the provided beta angle threshold.

This method does not change the current instance.

Parameters:

newBetaAngleThreshold - the beta angle threshold

Returns:

the new detector instance

withInertialFrame

public FieldBetaAngleDetector<T> withInertialFrame(Frame newFrame)

Create a new instance with the provided inertial frame.

This method does not change the current instance.

Parameters:

newFrame - the inertial frame

Returns:

the new detector instance

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 FieldEventDetector<T extends CalculusFieldElement<T>>

Specified by:

g in class FieldAbstractDetector<FieldBetaAngleDetector<T extends CalculusFieldElement<T>>,T extends CalculusFieldElement<T>>

Parameters:

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

Returns:

value of the switching function

calculateBetaAngle

public static <T extends CalculusFieldElement<T>> T calculateBetaAngle(FieldSpacecraftState<T> state,
                                                                       FieldPVCoordinatesProvider<T> celestialBodyProvider)

Calculate the beta angle between the orbit plane and the celestial body.

This method computes the beta angle using the frame from the spacecraft state.

Type Parameters:

T - The field type

Parameters:

state - spacecraft state

celestialBodyProvider - celestial body coordinate provider

Returns:

the beta angle (radians)

calculateBetaAngle

public static <T extends CalculusFieldElement<T>> T calculateBetaAngle(FieldSpacecraftState<T> state,
                                                                       FieldPVCoordinatesProvider<T> celestialBodyProvider,
                                                                       Frame frame)

Calculate the beta angle between the orbit plane and the celestial body.

Type Parameters:

T - The field type

Parameters:

state - spacecraft state

celestialBodyProvider - celestial body coordinate provider

frame - inertial frame in which beta angle will be computed

Returns:

the beta angle (radians)

create

protected FieldBetaAngleDetector<T> create(FieldAdaptableInterval<T> newMaxCheck,
                                           T newThreshold,
                                           int newMaxIter,
                                           FieldEventHandler<T> newHandler)

Build a new instance.

Specified by:

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

Parameters:

newMaxCheck - maximum checking interval

newThreshold - convergence threshold (s)

newMaxIter - maximum number of iterations in the event time search

newHandler - event handler to call at event occurrences

Returns:

a new instance of the appropriate sub-type