org.orekit.frames.transformations
Class GTODProvider

java.lang.Object
  org.orekit.frames.transformations.GTODProvider

All Implemented Interfaces:

Serializable, TransformProvider

public final class GTODProvider
extends Object
implements TransformProvider

Greenwich True Of Date Frame, also known as True of Date Rotating frame (TDR) or Greenwich Rotating Coordinate frame (GCR).

This frame handles the sidereal time according to IAU-82 model.

Its parent frame is the TODProvider.

The pole motion is not applied here.

Author:

Pascal Parraud, Thierry Ceolin

See Also:

Serialized Form

Constructor Summary

GTODProvider()
Simple constructor.

Method Summary

double	getGAST(AbsoluteDate date) Get the Greenwich apparent sidereal time, in radians.
static double	getGMST(AbsoluteDate date) Get the Greenwich mean sidereal time, in radians.
static double	getRotationRate(AbsoluteDate date) Get the rotation rate of the Earth.
Transform	getTransform(AbsoluteDate date) Get the transform from TOD at specified date.
Transform	getTransform(AbsoluteDate date, boolean computeSpinDerivatives) Get the transform from TOD at specified date.
Transform	getTransform(AbsoluteDate date, FramesConfiguration config) Get the transform from TOD at specified date.
Transform	getTransform(AbsoluteDate date, FramesConfiguration config, boolean computeSpinDerivatives) Get the transform from TOD at specified date.

Methods inherited from class java.lang.Object

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

Constructor Detail

GTODProvider

public GTODProvider()
             throws OrekitException

Simple constructor.

Throws:

OrekitException - if EOP parameters are desired but cannot be read

Method Detail

getTransform

public Transform getTransform(AbsoluteDate date)
                       throws OrekitException

Get the transform from TOD at specified date.

The update considers the Earth rotation from IERS data.

Specified by:

getTransform in interface TransformProvider

Parameters:

date - new value of the date

Returns:

transform at the specified date

Throws:

OrekitException - if the nutation model data embedded in the library cannot be read

getTransform

public Transform getTransform(AbsoluteDate date,
                              FramesConfiguration config)
                       throws OrekitException

Get the transform from TOD at specified date.

The update considers the Earth rotation from IERS data.

Specified by:

getTransform in interface TransformProvider

Parameters:

date - new value of the date

config - frames configuration to use

Returns:

transform at the specified date

Throws:

OrekitException - if the nutation model data embedded in the library cannot be read

getTransform

public Transform getTransform(AbsoluteDate date,
                              boolean computeSpinDerivatives)
                       throws OrekitException

Get the transform from TOD at specified date.

The update considers the Earth rotation from IERS data.

Specified by:

getTransform in interface TransformProvider

Parameters:

date - new value of the date

computeSpinDerivatives - not used

Returns:

transform at the specified date

Throws:

OrekitException - if the nutation model data embedded in the library cannot be read

getTransform

public Transform getTransform(AbsoluteDate date,
                              FramesConfiguration config,
                              boolean computeSpinDerivatives)
                       throws OrekitException

Get the transform from TOD at specified date.

The update considers the Earth rotation from IERS data.

Specified by:

getTransform in interface TransformProvider

Parameters:

date - new value of the date

config - frames configuration to use

computeSpinDerivatives - not used

Returns:

transform at the specified date

Throws:

OrekitException - if the nutation model data embedded in the library cannot be read

getGMST

public static double getGMST(AbsoluteDate date)
                      throws OrekitException

Get the Greenwich mean sidereal time, in radians.

Parameters:

date - current date

Returns:

Greenwich mean sidereal time, in radians

Throws:

OrekitException - if UTS taime scale cannot be retrieved

See Also:

getGAST(AbsoluteDate)

getGAST

public double getGAST(AbsoluteDate date)
               throws OrekitException

Get the Greenwich apparent sidereal time, in radians.

Greenwich apparent sidereal time is Greenwich mean sidereal time plus equation of equinoxes.

Parameters:

date - current date

Returns:

Greenwich apparent sidereal time, in radians

Throws:

OrekitException - if UTS taime scale cannot be retrieved

See Also:

getGMST(AbsoluteDate)

getRotationRate

public static double getRotationRate(AbsoluteDate date)
                              throws OrekitException

Get the rotation rate of the Earth.

Parameters:

date - given date

Returns:

the rotation rate

Throws:

OrekitException - if EOP data cannot be loaded