org.orekit.attitudes.directions
Class EarthCenterDirection

java.lang.Object
  org.orekit.attitudes.directions.EarthCenterDirection

All Implemented Interfaces:

IDirection, ITargetDirection

public class EarthCenterDirection
extends Object
implements ITargetDirection

Direction to Earth body center : the central body's center is the target point.

Since:

3.1

Version:

$Id: EarthCenterDirection.java 17582 2017-05-10 12:58:16Z bignon $

Author:

maggioranic

Concurrency :

immutable

Constructor Summary

EarthCenterDirection()
Constructor for Earth center direction.

Method Summary

Line	getLine(PVCoordinatesProvider pvCoord, AbsoluteDate date, Frame frame) Provides the line containing the origin (given PV coordinates) and directed by the direction vector.
PVCoordinates	getTargetPVCoordinates(AbsoluteDate date, Frame frame) Provides the target point at a given date in a given frame, represented by the associated PVCoordinates object
Vector3D	getVector(PVCoordinatesProvider pvCoord, AbsoluteDate date, Frame frame) Provides the direction vector at a given date in a given frame.

Methods inherited from class java.lang.Object

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

Constructor Detail

EarthCenterDirection

public EarthCenterDirection()

Constructor for Earth center direction. This direction is directed toward GCRF frame origin (i.e. Earth center).

Method Detail

getVector

public Vector3D getVector(PVCoordinatesProvider pvCoord,
                          AbsoluteDate date,
                          Frame frame)
                   throws OrekitException

Provides the direction vector at a given date in a given frame.

Specified by:

getVector in interface IDirection

Parameters:

pvCoord - the current coordinates of the origin point of the direction (may be null, in that specific case, the origin of the direction is the frame origin).

date - the date

frame - the frame to project the vector's coordinates

Returns:

the direction vector at the given date in the given frame

Throws:

OrekitException - if some frame specific errors occur

getLine

public Line getLine(PVCoordinatesProvider pvCoord,
                    AbsoluteDate date,
                    Frame frame)
             throws OrekitException

Provides the line containing the origin (given PV coordinates) and directed by the direction vector.

Specified by:

getLine in interface IDirection

Parameters:

pvCoord - the origin of the direction

date - the current date

frame - the expression frame of the line

Returns:

the Line of space containing the origin and direction vector

Throws:

OrekitException - if some frame specific errors occur

getTargetPVCoordinates

public PVCoordinates getTargetPVCoordinates(AbsoluteDate date,
                                            Frame frame)
                                     throws OrekitException

Provides the target point at a given date in a given frame, represented by the associated PVCoordinates object

Specified by:

getTargetPVCoordinates in interface ITargetDirection

Parameters:

date - the date

frame - the frame

Returns:

the PVCoordinates of the target

Throws:

OrekitException - if position cannot be computed in given frame