Package org.orekit.frames

Class GTODProvider

java.lang.Object

org.orekit.frames.GTODProvider

All Implemented Interfaces:

Serializable, EOPBasedTransformProvider, TransformProvider

public class GTODProvider
extends Object
implements EOPBasedTransformProvider

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

Constructors

Modifier	Constructor	Description
protected	GTODProvider(IERSConventions conventions, EOPHistory eopHistory)	Simple constructor.

Method Summary

Modifier and Type	Method	Description
EOPHistory	getEOPHistory()	Get the EOP history.
GTODProvider	getNonInterpolatingProvider()	Get a version of the provider that does not cache tidal corrections.
Transform	getTransform(AbsoluteDate date)	Get the Transform corresponding to specified date.
<T extends RealFieldElement<T>> FieldTransform<T>	getTransform(FieldAbsoluteDate<T> date)	Get the FieldTransform corresponding to specified date.

Methods inherited from class java.lang.Object

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

Constructor Detail

GTODProvider

protected GTODProvider(IERSConventions conventions,
                       EOPHistory eopHistory)
                throws OrekitException

Simple constructor.

Parameters:

conventions - IERS conventions to use

eopHistory - EOP history (may be null)

Throws:

OrekitException - if EOP parameters are desired but cannot be read

Method Detail

getEOPHistory

public EOPHistory getEOPHistory()

Get the EOP history.

Specified by:

getEOPHistory in interface EOPBasedTransformProvider

Returns:

EOP history

getNonInterpolatingProvider

public GTODProvider getNonInterpolatingProvider()
                                         throws OrekitException

Get a version of the provider that does not cache tidal corrections.

This method removes the performance enhancing interpolation features that are used by default in EOP-based provider, in order to focus on accuracy. The interpolation features are intended to save processing time by avoiding doing tidal correction evaluation at each time step and caching some results. This method can be used to avoid this (it is automatically called by FramesFactory.getNonInterpolatingTransform(Frame, Frame, AbsoluteDate), when very high accuracy is desired, or for testing purposes. It should be used with care, as doing the full computation is really costly.

Specified by:

getNonInterpolatingProvider in interface EOPBasedTransformProvider

Returns:

version of the provider that does not cache tidal corrections

Throws:

OrekitException - if EOP cannot be retrieved

See Also:

FramesFactory.getNonInterpolatingTransform(Frame, Frame, AbsoluteDate)

getTransform

public Transform getTransform(AbsoluteDate date)
                       throws OrekitException

Get the Transform corresponding to specified date.

Specified by:

getTransform in interface TransformProvider

Parameters:

date - current date

Returns:

transform at specified date

Throws:

OrekitException - if transform cannot be computed at given date

getTransform

public <T extends RealFieldElement<T>> FieldTransform<T> getTransform(FieldAbsoluteDate<T> date)

Get the FieldTransform corresponding to specified date.

Specified by:

getTransform in interface TransformProvider

Type Parameters:

T - type of the field elements

Parameters:

date - current date

Returns:

transform at specified date