EPSG guidance note #7-2, http://www.epsg.org 2019-02-21 true false true The same example as for the Time-specific Coordinate Frame rotation (coordinate operation method 1066) can be calculated, however in Step 2 the following transformation parameters have to be applied to achieve the same input and output in terms of coordinate values: Transformation parameters for the Position Vector transformation convention: tX = –0.003 m tY = –0.001 m tZ = 0.000 m rX = -0.019 msec rY = 0.042 msec rZ = -0.002 msec dS = 0.000 ppm from which M = 1.0 t = 2010.00 years Please note that only the rotation has changed sign as compared to the Coordinate Frame rotation. urn:ogc:def:method:EPSG::1065 Time-specific Position Vector transform (geocen) Note the analogy with the Time-specifc Coordinate Frame method (code 1066) but beware of the differences! Note: These formulas have been transcribed from EPSG Guidance Note #7-2. Users are encouraged to use that document rather than the text which follows as reference because limitations in the transcription will be avoided. Note: These formulas have been transcribed from EPSG Guidance Note #7-2. Users are encouraged to use that document rather than the text which follows as reference because limitations in the transcription will be avoided. The time-specific ooordinate transformation is an alternative approach to the time-dependent coordinate transformation. In this method the transformation parameter values are declared for a specified transformation reference epoch (an additional parameter for the transformation) and coordinates are adjusted to this epoch before the transformation is applied. This requires that the velocities for points whose coordinates are to be transformed are available. The time-specific transformation may then be applied as part of a concatenated coordinate operation in conjunction with one or two point motion operations (see EPSG Guidance Note 7-3 section 3) in two or three steps: i) change the source CRS Cartesian coordinates from their dataset coordinate epoch to the transformation reference epoch at which the time-specific transformation is valid; ii) apply the Time-specific Position Vector transformation; iii) change the target CRS Cartesian coordinates from the transformation reference epoch at which the time-specific transformation is valid to any other desired coordinate epoch. The transformation reference epoch of the Time-specific Position Vector transformation is used as the target epoch (t2) in step (i) and as the source epoch (t1) in step (iii). It is not used in step (ii).