org.orekit.attitudes

Class TargetPointing

java.lang.Object

org.orekit.attitudes.GroundPointing

org.orekit.attitudes.TargetPointing

All Implemented Interfaces:

Serializable, AttitudeProvider

public class TargetPointing
extends GroundPointing

This class handles target pointing attitude provider.

This class represents the attitude provider where the satellite z axis is pointing to a ground point target.

The target position is defined in a body frame specified by the user. It is important to make sure this frame is consistent.

The object TargetPointing is guaranteed to be immutable.

Author:

Véronique Pommier-Maurussane

See Also:

GroundPointing, Serialized Form

Constructor Summary

Constructors

Constructor and Description
TargetPointing(Frame inertialFrame, Frame bodyFrame, Vector3D target) Creates a new instance from body frame and target expressed in cartesian coordinates.
TargetPointing(Frame inertialFrame, GeodeticPoint targetGeo, BodyShape shape) Creates a new instance from body shape and target expressed in geodetic coordinates.

Method Summary

Modifier and Type	Method and Description
protected TimeStampedPVCoordinates	getTargetPV(PVCoordinatesProvider pvProv, AbsoluteDate date, Frame frame) Compute the target point position/velocity in specified frame.

Methods inherited from class org.orekit.attitudes.GroundPointing

getAttitude, getBodyFrame

Methods inherited from class java.lang.Object

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

Constructor Detail

TargetPointing

public TargetPointing(Frame inertialFrame,
                      Frame bodyFrame,
                      Vector3D target)
               throws OrekitException

Creates a new instance from body frame and target expressed in cartesian coordinates.

Parameters:

inertialFrame - frame in which orbital velocities are computed

bodyFrame - body frame.

target - target position in body frame

Throws:

OrekitException - if the first frame specified is not a pseudo-inertial frame

Since:

7.1

TargetPointing

public TargetPointing(Frame inertialFrame,
                      GeodeticPoint targetGeo,
                      BodyShape shape)
               throws OrekitException

Creates a new instance from body shape and target expressed in geodetic coordinates.

Parameters:

inertialFrame - frame in which orbital velocities are computed

targetGeo - target defined as a geodetic point in body shape frame

shape - body shape

Throws:

OrekitException - if the frame specified is not a pseudo-inertial frame

Since:

7.1

Method Detail

getTargetPV

protected TimeStampedPVCoordinates getTargetPV(PVCoordinatesProvider pvProv,
                                               AbsoluteDate date,
                                               Frame frame)
                                        throws OrekitException

Compute the target point position/velocity in specified frame.

Specified by:

getTargetPV in class GroundPointing

Parameters:

pvProv - provider for PV coordinates

date - date at which target point is requested

frame - frame in which observed ground point should be provided

Returns:

observed ground point position (element 0) and velocity (at index 1) in specified frame

Throws:

OrekitException - if some specific error occurs, such as no target reached