Package org.orekit.bodies

Class FieldEllipse<T extends CalculusFieldElement<T>>

java.lang.Object

org.orekit.bodies.FieldEllipse<T>

Type Parameters:

T - the type of the field elements

public class FieldEllipse<T extends CalculusFieldElement<T>>
extends Object

Model of a 2D ellipse in 3D space.

These ellipses are mainly created as plane sections of general 3D ellipsoids, but can be used for other purposes.

Instances of this class are guaranteed to be immutable.

Since:

12.0

Author:

Luc Maisonobe

See Also:

Ellipsoid.getPlaneSection(FieldVector3D, FieldVector3D)

Constructor Summary

Constructors

Constructor	Description
FieldEllipse(FieldVector3D<T> center, FieldVector3D<T> u, FieldVector3D<T> v, T a, T b, Frame frame)	Simple constructor.

Method Summary

Modifier and Type	Method	Description
T	getA()	Get the semi major axis.
T	getB()	Get the semi minor axis.
FieldVector3D<T>	getCenter()	Get the center of the 2D ellipse.
FieldVector2D<T>	getCenterOfCurvature(FieldVector2D<T> point)	Find the center of curvature (point on the evolute) at the nadir of a point.
Frame	getFrame()	Get the defining frame.
FieldVector3D<T>	getU()	Get the unit vector along the major axis.
FieldVector3D<T>	getV()	Get the unit vector along the minor axis.
FieldVector3D<T>	pointAt(T theta)	Get a point of the 2D ellipse.
FieldVector2D<T>	projectToEllipse(FieldVector2D<T> p)	Find the closest ellipse point.
TimeStampedFieldPVCoordinates<T>	projectToEllipse(TimeStampedFieldPVCoordinates<T> pv)	Project position-velocity-acceleration on an ellipse.
FieldVector2D<T>	toPlane(FieldVector3D<T> p)	Project a point to the ellipse plane.
FieldVector3D<T>	toSpace(FieldVector2D<T> p)	Create a point from its ellipse-relative coordinates.

Methods inherited from class java.lang.Object

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

Constructor Detail

FieldEllipse

public FieldEllipse(FieldVector3D<T> center,
                    FieldVector3D<T> u,
                    FieldVector3D<T> v,
                    T a,
                    T b,
                    Frame frame)

Simple constructor.

Parameters:

center - center of the 2D ellipse

u - unit vector along the major axis

v - unit vector along the minor axis

a - semi major axis

b - semi minor axis

frame - frame in which the ellipse is defined

Method Detail

getCenter

public FieldVector3D<T> getCenter()

Get the center of the 2D ellipse.

Returns:

center of the 2D ellipse

getU

public FieldVector3D<T> getU()

Get the unit vector along the major axis.

Returns:

unit vector along the major axis

getV

public FieldVector3D<T> getV()

Get the unit vector along the minor axis.

Returns:

unit vector along the minor axis

getA

public T getA()

Get the semi major axis.

Returns:

semi major axis

getB

public T getB()

Get the semi minor axis.

Returns:

semi minor axis

getFrame

public Frame getFrame()

Get the defining frame.

Returns:

defining frame

pointAt

public FieldVector3D<T> pointAt(T theta)

Get a point of the 2D ellipse.

Parameters:

theta - angular parameter on the ellipse (really the eccentric anomaly)

Returns:

ellipse point at theta, in underlying ellipsoid frame

toSpace

public FieldVector3D<T> toSpace(FieldVector2D<T> p)

Create a point from its ellipse-relative coordinates.

Parameters:

p - point defined with respect to ellipse

Returns:

point defined with respect to 3D frame

See Also:

toPlane(FieldVector3D)

toPlane

public FieldVector2D<T> toPlane(FieldVector3D<T> p)

Project a point to the ellipse plane.

Parameters:

p - point defined with respect to 3D frame

Returns:

point defined with respect to ellipse

See Also:

toSpace(FieldVector2D)

projectToEllipse

public FieldVector2D<T> projectToEllipse(FieldVector2D<T> p)

Find the closest ellipse point.

Parameters:

p - point in the ellipse plane to project on the ellipse itself

Returns:

closest point belonging to 2D meridian ellipse

projectToEllipse

public TimeStampedFieldPVCoordinates<T> projectToEllipse(TimeStampedFieldPVCoordinates<T> pv)

Project position-velocity-acceleration on an ellipse.

Parameters:

pv - position-velocity-acceleration to project, in the reference frame

Returns:

projected position-velocity-acceleration

getCenterOfCurvature

public FieldVector2D<T> getCenterOfCurvature(FieldVector2D<T> point)

Find the center of curvature (point on the evolute) at the nadir of a point.

Parameters:

point - point in the ellipse plane

Returns:

center of curvature of the ellipse directly at point nadir