[Proj] datum does not change?

Robert Jaeschke robert-j at gmx.de
Mon Mar 21 16:46:01 EST 2005


On Mon, Mar 21, 2005 at 03:53:58PM -0500, you wrote:
> > Why do I always get the same result? Changing the datum doesn't seem to
> > have an effect on the output? I expect something that is much nearer to
> > "12d10'27.403"E  51d41'38.33"N" than the result below.
> The proj and invproj commands do not utilize datum information. If
> you want to convert locations between two datums you will need
> to use the cs2cs commandline program.  The proj and invproj
> programs stick strictly to the projection<->lat/long conversion on the
> stated ellipsoid. 

I knew, it was my mistake. All examples used cs2cs because they converted 
to UTM and I needed lat/long, so I thought invproj would be best ...

But that leads me to another question: if I use 
> invproj +init:epsg=31464 
then the datum isn't converted, although EPSG:31467 has the
+datum=potsdam switch? I think, that would be very strange.

So what I want is:

cs2cs +init=epsg:31467 +to +proj=latlong +datum=WGS84


Thank you, Robert

"I don't even have an e-mail address. I have reached an age where my main
purpose is not to receive messages." 
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