[Proj] Problems with EOV for Hungary (1972 Egyseges Orszagos Vetuleti)
Mikael.Rittri at carmenta.com
Tue Sep 22 05:45:32 EST 2009
> Roger Oberholtzer wrote:
> > - - -
> > When I run some test data, I am always 80 some meters away.
> You are missing the +towgs84 parameter, which is necessary
> if you want PROJ.4 to perform a datum change.
Yes. I looked at www.epsg-registry.org, and searched on
Type: Coordinate Transformation
This gave a couple of 3-parameter and 7-parameter transforms
for HD72. As usual, some of them were informally deprecated
in the comments field, but not formally DEPRECATED in the
technical sense. Anyway, the best one seems to be
EPSG:1448 "HD72 to WGS 84 (3)"
which has the same parameters as
EPSG:1449 "HD72 to ETRS89 (2)",
X-axis translation 52.684 metre
Y-axis translation -71.194 metre
Z-axis translation -13.975 metre
X-axis rotation 0.312 arc-second
Y-axis rotation 0.1063 arc-second
Z-axis rotation 0.3729 arc-second
Scale difference 1.0191 parts per million
However, there is a warning _above_ these parameters:
"Care! Ensure application uses this method! See Guidance Note 7-1"
which means that you must scroll _down_ to the bottom line, where you find
+Method [Coordinate Frame rotation]
and, since PROJ.4 uses the opposite sign convention for the rotation
angles (the Position Vector Transform), these angles must be negated.
So, I think you should use
to implement HD72.
From: proj-bounces at lists.maptools.org [mailto:proj-bounces at lists.maptools.org] On Behalf Of Jean-Claude REPETTO
Sent: den 22 september 2009 11:57
To: PROJ.4 and general Projections Discussions; roger at opq.se
Subject: Re: [Proj] Problems with EOV for Hungary (1972 Egyseges Orszagos Vetuleti)
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