org.orekit.attitudes
Class LofOffsetPointing

java.lang.Object
  org.orekit.attitudes.AbstractAttitudeLaw
      org.orekit.attitudes.GroundPointing
          org.orekit.attitudes.LofOffsetPointing

All Implemented Interfaces:

Serializable, AttitudeLaw, AttitudeProvider

public class LofOffsetPointing
extends GroundPointing

This class provides a default attitude provider.

The attitude pointing law is defined by an attitude provider and the satellite axis vector chosen for pointing.

Author:

Véronique Pommier-Maurussane

See Also:

Serialized Form

Constructor Summary

LofOffsetPointing(BodyShape shape, AttitudeProvider attLaw, Vector3D satPointingVector)
Creates new instance.

Method Summary

Attitude	getAttitude(PVCoordinatesProvider pvProv, AbsoluteDate date, Frame frame) Compute the attitude corresponding to an orbital state.
protected Vector3D	getTargetPoint(PVCoordinatesProvider pvProv, AbsoluteDate date, Frame frame) Compute the target point in specified frame.
void	setSpinDerivativesComputation(boolean computeSpinDerivatives) Method to activate spin derivative computation.

Methods inherited from class org.orekit.attitudes.GroundPointing

getBodyFrame, getBodyShape, getTargetPV

Methods inherited from class org.orekit.attitudes.AbstractAttitudeLaw

getAttitude, getSpinDerivativesComputation

Methods inherited from class java.lang.Object

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

Constructor Detail

LofOffsetPointing

public LofOffsetPointing(BodyShape shape,
                         AttitudeProvider attLaw,
                         Vector3D satPointingVector)

Creates new instance.

Parameters:

shape - Body shape

attLaw - Attitude law

satPointingVector - satellite vector defining the pointing direction

Method Detail

getAttitude

public Attitude getAttitude(PVCoordinatesProvider pvProv,
                            AbsoluteDate date,
                            Frame frame)
                     throws OrekitException

Compute the attitude corresponding to an orbital state.

Specified by:

getAttitude in interface AttitudeProvider

Overrides:

getAttitude in class GroundPointing

Parameters:

pvProv - local position-velocity provider around current date

date - current date

frame - reference frame from which attitude is computed

Returns:

attitude attitude on the specified date and position-velocity state

Throws:

OrekitException - if attitude cannot be computed

getTargetPoint

protected Vector3D getTargetPoint(PVCoordinatesProvider pvProv,
                                  AbsoluteDate date,
                                  Frame frame)
                           throws OrekitException

Compute the target point in specified frame.

Specified by:

getTargetPoint 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 in specified frame

Throws:

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

setSpinDerivativesComputation

public void setSpinDerivativesComputation(boolean computeSpinDerivatives)
                                   throws OrekitException

Method to activate spin derivative computation.

Spin derivatives computation applies to provided law attitudeLaw.

Specified by:

setSpinDerivativesComputation in interface AttitudeProvider

Overrides:

setSpinDerivativesComputation in class AbstractAttitudeLaw

Parameters:

computeSpinDerivatives - true if spin derivatives should be computed

Throws:

OrekitException - if spin derivatives can not be computed