[mapserver-users] UTM projection

[Thorsten Fischer]

Hi list,

I am using the mapserver in a smoothly working CGI application, similar to the
official example. It lets Netscape display a simple 'document contains no
data' window after I made a change in projection.


I have a .map file with roughly the following content:

----

<header>

PROJECTION
  "proj=merc"
  "ellps=sphere"
END

LAYER
  PROJECTION
    "geographic"
    "ellps=WGS84"
  END
END

<lotsa more layers>

----

which works as it is supposed to. For some reasons, I have to switch the
projection over to UTM, which I thought would be done by replacing the
projection field with:

PROJECTION
  "proj=utm"      # projection
  "ellps=GRS80"   # or whatever ellipsoid seems to fit
  "zone=32"       # we are in germany
  "north"         # northern hemisphere
  "no_defs"       # ?
END

Please bear with me because I am not a cartographer. According to the usual
lists germany is UTM zone 32, and I do not know what 'no_defs' means.

The extents are set correctly (they do not differ much from the mercator
projection, which, as far as I understand these things, is of no surprise).

What am I doing wrong?




On a completely unrelated note, it would me nice to have the syntax of the
.map file's setions unified. I think it would be preferable to have
something like

PROJECTION
  TYPE merc
  ZONE 32
  [ ... ]
END

instead of the syntax you all know about, which may be easier to pass to a call
of the proj library without parsing but which is confusing the user (some of
ours at least).


Greetings from the sun-flooded places of northern Berlin,

Thorsten

-- 

Thorsten Fischer          thfischer at mapmedia.de

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