fr.cnes.sirius.patrius.attitudes.directions

Class ToCelestialPointDirection

java.lang.Object

fr.cnes.sirius.patrius.attitudes.directions.ToCelestialPointDirection

All Implemented Interfaces:

IDirection, ITargetDirection, Serializable

public final class ToCelestialPointDirection
extends Object
implements ITargetDirection

Direction described by a celestial point: the celestial point is the target point.

Since:

1.1

Author:

Thomas Trapier

See Also:

Serialized Form

Concurrency :

conditionally thread-safe

Concurrency comment :

The use of a celestial point linked to the tree of frames makes this class thread-safe only if the underlying CelestialPoint is too.

Nested Class Summary

Nested classes/interfaces inherited from interface fr.cnes.sirius.patrius.attitudes.directions.ITargetDirection

ITargetDirection.AberrationCorrection, ITargetDirection.SignalDirection

Constructor Summary

Constructors

Constructor and Description
ToCelestialPointDirection(CelestialPoint celestialPoint) Build a direction described by a celestial point: the celestial point is the target point.

Method Summary

Modifier and Type	Method and Description
Line	getLine(PVCoordinatesProvider origin, AbsoluteDate date, Frame frame) Provides the line containing the origin (given PV coordinates) and directed by the direction vector.
Line	getLine(PVCoordinatesProvider origin, ITargetDirection.SignalDirection signalDirection, ITargetDirection.AberrationCorrection correction, AbsoluteDate date, VacuumSignalPropagationModel.FixedDate fixedDateType, Frame frame, double epsilon) Provides the half line containing both origin and target, taking into account the type of date (emission or reception), corrected for light-time and stellar aberration pending the entered correction parameter.
PVCoordinates	getTargetPVCoordinates(AbsoluteDate date, Frame frame) Provides the target point at a given date in a given frame, represented by the associated PVCoordinates object.
PVCoordinatesProvider	getTargetPvProvider() Provides the PVCoordinatesProvider associated to the target object.
Vector3D	getVector(PVCoordinatesProvider origin, 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

Methods inherited from interface fr.cnes.sirius.patrius.attitudes.directions.ITargetDirection

getVector

Constructor Detail

ToCelestialPointDirection

public ToCelestialPointDirection(CelestialPoint celestialPoint)

Build a direction described by a celestial point: the celestial point is the target point.

Parameters:

celestialPoint - the celestial point

Method Detail

getVector

public Vector3D getVector(PVCoordinatesProvider origin,
                          AbsoluteDate date,
                          Frame frame)
                   throws PatriusException

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

Specified by:

getVector in interface IDirection

Parameters:

origin - 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 (from origin to target) at the given date in the given frame

Throws:

PatriusException - if some frame specific errors occur

getTargetPVCoordinates

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

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:

PatriusException - if position cannot be computed in given frame

getLine

public Line getLine(PVCoordinatesProvider origin,
                    AbsoluteDate date,
                    Frame frame)
             throws PatriusException

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

Specified by:

getLine in interface IDirection

Parameters:

origin - the origin of the direction

date - the current date

frame - the expression frame of the line

Returns:

the half Line of space from the origin position at given date and containing the direction vector

Throws:

PatriusException - if some frame specific errors occur

getLine

public Line getLine(PVCoordinatesProvider origin,
                    ITargetDirection.SignalDirection signalDirection,
                    ITargetDirection.AberrationCorrection correction,
                    AbsoluteDate date,
                    VacuumSignalPropagationModel.FixedDate fixedDateType,
                    Frame frame,
                    double epsilon)
             throws PatriusException

Provides the half line containing both origin and target, taking into account the type of date (emission or reception), corrected for light-time and stellar aberration pending the entered correction parameter.

Nota: if entered correction is NONE, invoking this method is not fully equivalent to invoking the method IDirection.getLine(PVCoordinatesProvider, AbsoluteDate, Frame) due to orientation of the half line (from the origin position at entered date in the target direction, or from the target position at entered date in the origin direction).

Specified by:

getLine in interface ITargetDirection

Parameters:

origin - 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).

signalDirection - the signal direction

correction - the type of correction for light-time and stellar aberration (NONE, LT, S, or LT_S, see aberration corrections). In case of S or of LT_S correction, the stellar aberration is corrected at reception if RECEPTION date type or at transmission if EMISSION date type.

date - the date for origin

fixedDateType - the type of the previous given date : emission or reception

frame - the frame to project the line

epsilon - the absolute duration threshold used for convergence of signal propagation computation. The epsilon is a time absolute error (ex: 1E-14s, in this case, the signal distance accuracy is 1E-14s x 3E8m/s = 3E-6m).

Returns:

the half line of space, at the given date in the given frame, corrected for the given aberration:

• if RECEPTION date FROM_TARGET: half line from the origin position at fixed date, in the target apparent direction;
• if RECEPTION date TOWARD_TARGET: half line from the target position at fixed date, in the origin apparent direction;
• if EMISSION date TOWARD_TARGET: half line from the origin position at fixed date, in the target corrected direction;
• if EMISSION date FROM_TARGET: half line from the target position at fixed date, in the origin corrected direction.

Throws:

PatriusException - if some frame specific errors occur

getTargetPvProvider

public PVCoordinatesProvider getTargetPvProvider()

Provides the PVCoordinatesProvider associated to the target object.

Specified by:

getTargetPvProvider in interface ITargetDirection

Returns:

the PV coordinates provider of the target