[Proj] Meaning of 7-parameter transformation rotations
martin.vermeer at hut.fi
Wed Nov 30 15:55:54 EST 2005
On Wed, Nov 30, 2005 at 12:58:19PM -0600, Clifford J Mugnier wrote:
> Note that the SENSE of the rotations have two common usages. The American
> Standard versus the European Standard differ! To transform in the same
> direction, the signs are OPPOSITE from one "standard" to another.
> Generally speaking, a 7-parameter transformation, whether it is a
> Bursa-Wolfe or a Molodensky, MUST have a "test point" provided so that the
> user knows which sense the rotations need for the desired transformation
> The Americans, Australians, and Luxemborgs use one SENSE, the Europeans use
> the other. In regard to the rest of the world, it depends on which
> brand-name of GPS Geodetic Processing software was used to derive the
> parameters from some collection of data points. See my monthly column for
> such important minutiae for country to country considerations.
> Be careful of 'dem signs! :-)
Yes <sigh>, quite true. Perhaps it would be best to just add the matrix
equation in ASCII art to the text.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Size: 189 bytes
Desc: not available
Url : http://lists.maptools.org/pipermail/proj/attachments/20051130/bf8f06df/attachment.bin
More information about the Proj