fr.cnes.sirius.patrius.attitudes

Class YawCompensation

java.lang.Object

fr.cnes.sirius.patrius.attitudes.AbstractAttitudeLaw

fr.cnes.sirius.patrius.attitudes.AbstractGroundPointing

fr.cnes.sirius.patrius.attitudes.AbstractGroundPointingWrapper

fr.cnes.sirius.patrius.attitudes.YawCompensation

All Implemented Interfaces:

AttitudeLaw, AttitudeLawModifier, AttitudeProvider, Serializable

public class YawCompensation
extends AbstractGroundPointingWrapper

This class handles yaw compensation attitude provider.

Yaw compensation is mainly used for Earth observation satellites. As a satellites moves along its track, the image of ground points move on the focal point of the optical sensor. This motion is a combination of the satellite motion, but also on the Earth rotation and on the current attitude (in particular if the pointing includes Roll or Pitch offset). In order to reduce geometrical distortion, the yaw angle is changed a little from the simple ground pointing attitude such that the apparent motion of ground points is along a prescribed axis (orthogonal to the optical sensors rows), taking into account all effects.

This attitude is implemented as a wrapper on top of an underlying ground pointing law that defines the roll and pitch angles.

Instances of this class are guaranteed to be immutable.

Author:

Véronique Pommier-Maurussane

See Also:

GroundPointing, Serialized Form

Constructor Summary

Constructors

Constructor and Description
YawCompensation(AbstractGroundPointing groundPointingLaw) Creates a new instance.
YawCompensation(AbstractGroundPointing groundPointingLaw, Vector3D losInSatFrameVec, Vector3D losNormalInSatFrameVec) Creates a new instance with specified los axis in satellite frame.

Method Summary

Modifier and Type	Method and Description
Attitude	getAttitude(PVCoordinatesProvider pvProv, AbsoluteDate date, Frame frame) Compute the attitude corresponding to an orbital state.
TimeStampedAngularCoordinates	getCompensation(PVCoordinatesProvider pvProv, AbsoluteDate date, Frame orbitFrame, Attitude base) Compute the TimeStampedAngularCoordinates at a given time.
double	getYawAngle(PVCoordinatesProvider pvProv, AbsoluteDate date, Frame frame) Compute the yaw compensation angle at date.

Methods inherited from class fr.cnes.sirius.patrius.attitudes.AbstractGroundPointingWrapper

getBaseState, getGroundPointingLaw, getTargetPoint, getTargetPV, getUnderlyingAttitudeLaw, setSpinDerivativesComputation

Methods inherited from class fr.cnes.sirius.patrius.attitudes.AbstractGroundPointing

getBodyFrame, getBodyShape

Methods inherited from class fr.cnes.sirius.patrius.attitudes.AbstractAttitudeLaw

getAttitude, getSpinDerivativesComputation

Methods inherited from class java.lang.Object

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

Methods inherited from interface fr.cnes.sirius.patrius.attitudes.AttitudeProvider

getAttitude

Constructor Detail

YawCompensation

public YawCompensation(AbstractGroundPointing groundPointingLaw)

Creates a new instance.

Parameters:

groundPointingLaw - ground pointing attitude provider without yaw compensation

YawCompensation

public YawCompensation(AbstractGroundPointing groundPointingLaw,
                       Vector3D losInSatFrameVec,
                       Vector3D losNormalInSatFrameVec)

Creates a new instance with specified los axis in satellite frame.

Parameters:

groundPointingLaw - ground pointing attitude provider without yaw compensation

losInSatFrameVec - LOS in satellite frame axis

losNormalInSatFrameVec - LOS normal axis in satellite frame

Method Detail

getAttitude

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

Compute the attitude corresponding to an orbital state.

Specified by:

getAttitude in interface AttitudeProvider

Overrides:

getAttitude in class AbstractGroundPointing

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:

PatriusException - if attitude cannot be computed

getCompensation

public TimeStampedAngularCoordinates getCompensation(PVCoordinatesProvider pvProv,
                                                     AbsoluteDate date,
                                                     Frame orbitFrame,
                                                     Attitude base)
                                              throws PatriusException

Compute the TimeStampedAngularCoordinates at a given time.

Specified by:

getCompensation in class AbstractGroundPointingWrapper

Parameters:

pvProv - provider for PV coordinates

date - date at which rotation is requested

orbitFrame - reference frame from which attitude is computed

base - base satellite attitude in given frame.

Returns:

compensation rotation at date, i.e rotation between non compensated attitude state and compensated state.

Throws:

PatriusException - if some specific error occurs

getYawAngle

public double getYawAngle(PVCoordinatesProvider pvProv,
                          AbsoluteDate date,
                          Frame frame)
                   throws PatriusException

Compute the yaw compensation angle at date.

Parameters:

pvProv - provider for PV coordinates

date - date at which compensation is requested

frame - reference frame from which attitude is computed

Returns:

yaw compensation angle for orbit.

Throws:

PatriusException - if some specific error occurs