[Proj] WGS84 definition
Oscar van Vlijmen
ovv at hetnet.nl
Mon Dec 5 17:53:32 EST 2005
> From: Martin Vermeer <martin.vermeer-hut.fi>
> As for Europe, that was just an example. Of course as an alternative,
> ITRF with time dependent transformations is possible in principle, and
> unavoidable on this precision level. This would be global in scope.
Does this imply that on our Christmas wish list for transforms in PROJ.4 is
a 14-parameter Helmert transform?
Hmm, can be done by the regular 7-param transform, taking care of the signs,
and including some epoch pre-calculation.
Not difficult. Read for instance the 5-page article:
"International Terrestrial Reference Frame (ITRF) to GDA94 Coordinate
Transformations", J. Dawson and J. Steed, Geoscience Australia, 2004
or if that doesn't work:
For NAD83 <-> ITRF transformations already several software and on-line
See also the National Geodetic Survey (NGS)
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