fr.cnes.sirius.patrius.frames.transformations

Class HelmertTransformation

java.lang.Object

fr.cnes.sirius.patrius.frames.transformations.HelmertTransformation

All Implemented Interfaces:

TransformProvider, Serializable

public class HelmertTransformation
extends Object
implements TransformProvider

Transformation class for geodetic systems.

The Helmert transformation is mainly used to convert between various realizations of geodetic frames, for example in the ITRF family.

The original Helmert transformation is a 14 parameters transform that includes translation, velocity, rotation, rotation rate and scale factor. The scale factor is useful for coordinates near Earth surface, but it cannot be extended to outer space as it would correspond to a non-unitary transform. Therefore, the scale factor is not used here.

Instances of this class are guaranteed to be immutable.

Spin derivative is never computed and is either 0 or null. No analytical formula is currently available for spin derivative although it could be derived.

Frames configuration is unused.

Since:

5.1

Author:

Luc Maisonobe

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
HelmertTransformation(AbsoluteDate epochIn, double t1, double t2, double t3, double r1, double r2, double r3, double t1Dot, double t2Dot, double t3Dot, double r1Dot, double r2Dot, double r3Dot) Build a transform from its primitive operations.

Method Summary

Modifier and Type	Method and Description
PVCoordinates	getCartesian() Returns the Cartesian part of the transform.
AbsoluteDate	getEpoch() Get the reference epoch of the transform.
Vector3D	getRotationRate() Returns the first time derivative of the rotation (norm representing angular rate).
Vector3D	getRotationVector() Returns the global rotation vector (applying rotation is done by computing cross product).
Transform	getTransform(AbsoluteDate date) Compute the transform at some date.
Transform	getTransform(AbsoluteDate date, boolean computeSpinDerivatives) Compute the transform at some date.
Transform	getTransform(AbsoluteDate date, FramesConfiguration config) Compute the transform at some date.
Transform	getTransform(AbsoluteDate date, FramesConfiguration config, boolean computeSpinDerivatives) Compute the transform at some date.

Methods inherited from class java.lang.Object

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

Constructor Detail

HelmertTransformation

public HelmertTransformation(AbsoluteDate epochIn,
                             double t1,
                             double t2,
                             double t3,
                             double r1,
                             double r2,
                             double r3,
                             double t1Dot,
                             double t2Dot,
                             double t3Dot,
                             double r1Dot,
                             double r2Dot,
                             double r3Dot)

Build a transform from its primitive operations.

Parameters:

epochIn - reference epoch of the transform

t1 - translation parameter along X axis (BEWARE, this is in mm)

t2 - translation parameter along Y axis (BEWARE, this is in mm)

t3 - translation parameter along Z axis (BEWARE, this is in mm)

r1 - rotation parameter around X axis (BEWARE, this is in mas)

r2 - rotation parameter around Y axis (BEWARE, this is in mas)

r3 - rotation parameter around Z axis (BEWARE, this is in mas)

t1Dot - rate of translation parameter along X axis (BEWARE, this is in mm/y)

t2Dot - rate of translation parameter along Y axis (BEWARE, this is in mm/y)

t3Dot - rate of translation parameter along Z axis (BEWARE, this is in mm/y)

r1Dot - rate of rotation parameter around X axis (BEWARE, this is in mas/y)

r2Dot - rate of rotation parameter around Y axis (BEWARE, this is in mas/y)

r3Dot - rate of rotation parameter around Z axis (BEWARE, this is in mas/y)

Method Detail

getEpoch

public AbsoluteDate getEpoch()

Get the reference epoch of the transform.

Returns:

reference epoch of the transform

getCartesian

public PVCoordinates getCartesian()

Returns the Cartesian part of the transform.

Returns:

the Cartesian part of the transform

getRotationVector

public Vector3D getRotationVector()

Returns the global rotation vector (applying rotation is done by computing cross product).

Returns:

the global rotation vector (applying rotation is done by computing cross product)

getRotationRate

public Vector3D getRotationRate()

Returns the first time derivative of the rotation (norm representing angular rate).

Returns:

the first time derivative of the rotation (norm representing angular rate)

getTransform

public Transform getTransform(AbsoluteDate date)
                       throws PatriusException

Compute the transform at some date.

Specified by:

getTransform in interface TransformProvider

Parameters:

date - date at which the transform is desired

Returns:

computed transform at specified date

Throws:

PatriusException - if the default config cannot be retrieved

getTransform

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

Compute the transform at some date.

Frames configuration is unused.

Specified by:

getTransform in interface TransformProvider

Parameters:

date - date at which the transform is desired

config - frames configuration to use

Returns:

computed transform at specified date

Throws:

PatriusException - if problem in the frame configuration

getTransform

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

Compute the transform at some date.

Spin derivative is never computed and is either 0 or null. No analytical formula is currently available for spin derivative although it could be derived.

Specified by:

getTransform in interface TransformProvider

Parameters:

date - date at which the transform is desired

computeSpinDerivatives - Spin derivatives are computed : true or not : false

Returns:

computed transform at specified date

Throws:

PatriusException - if default frame configuration cannot be retrieved

getTransform

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

Compute the transform at some date.

Spin derivative is never computed and is either 0 or null. No analytical formula is currently available for spin derivative although it could be derived.

Frames configuration is unused.

Specified by:

getTransform in interface TransformProvider

Parameters:

date - date at which the transform is desired

config - frames configuration to use

computeSpinDerivatives - Spin derivatives are computed : true or not : false

Returns:

computed transform at specified date

Throws:

PatriusException - if problem in the frame configuration