org.orekit.attitudes

Class GroundPointing

java.lang.Object

org.orekit.attitudes.GroundPointing

All Implemented Interfaces:

Serializable, AttitudeProvider

Direct Known Subclasses:

BodyCenterPointing, LofOffsetPointing, NadirPointing, TargetPointing, YawCompensation, YawSteering

public abstract class GroundPointing
extends Object
implements AttitudeProvider

Base class for ground pointing attitude providers.

This class is a basic model for different kind of ground pointing attitude providers, such as : body center pointing, nadir pointing, target pointing, etc...

The object GroundPointing is guaranteed to be immutable.

Author:

Véronique Pommier-Maurussane

See Also:

AttitudeProvider, Serialized Form

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	GroundPointing(Frame bodyFrame) Default constructor.

Method Summary

Methods

Modifier and Type	Method and Description
Attitude	getAttitude(PVCoordinatesProvider pvProv, AbsoluteDate date, Frame frame) Compute the attitude corresponding to an orbital state.
Frame	getBodyFrame() Get the body frame.
protected abstract TimeStampedPVCoordinates	getTargetPV(PVCoordinatesProvider pvProv, AbsoluteDate date, Frame frame) Compute the target point position/velocity in specified frame.

Methods inherited from class java.lang.Object

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

Constructor Detail

GroundPointing

protected GroundPointing(Frame bodyFrame)

Default constructor. Build a new instance with arbitrary default elements.

Parameters:

bodyFrame - the frame that rotates with the body

Method Detail

getBodyFrame

public Frame getBodyFrame()

Get the body frame.

Returns:

body frame

getTargetPV

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

Compute the target point position/velocity in specified frame.

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

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

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