Hi,
Your projectin setting is likely to give you unpredictable results, because
init:epsg:26915 means
<26915> +proj=utm +zone=15 +ellps=GRS80 +datum=NAD83 +units=m +no_defs <>
and now you are giving additional, different definitions for the type of
projection, ellipsoid and datum.
What do you know about your old maps? Obviously they were not originally in
digital format but they have been scanned later, oriented to North-South and
georeferenced with world file or something? It is quite possible that you can
find out the exact projection that was used for producing the map but it is a
good start that you know it is Gauss-Krüger. Below are two proj4 strings for
Gauss-Krüger projections
# DHDN / 3-degree Gauss zone 2 (deprecated) German
+proj=tmerc +lat_0=0 +lon_0=6 +k=1 +x_0=2500000 +y_0=0 +ellps=bessel
+datum=potsdam +units=m +no_defs <>
#Finnish KKJ
tmerc +lat_0=0 +lon_0=27 +k=1 +x_0=3500000 +y_0=0 +ellps=intl
+towgs84=-96.0617,-82.4278,-121.743,4.80107,0.34543,-1.37646,1.4964 +units=m
+no_defs <>
What you need to chase up are
proj=tmerc #this is clear, Gauss-Krüger is a transverse Mercator projection
lat_0 #origin of latitude
lon_0 #origin of longitude, the central meridian of the projection zone
k #scale factor, I suppose it is usually 1 in European Gauss-Kruger
projections
x_0 #false easting in meters
y_0 #false northing in meters
ellps #name of the ellipsoid; may be hard to find an accurate equivalent
to 1908 situation
datum #name of the datum; same as above
towgs84 #affine transformation parameters, usually either datum or towgs84 are
needed
-Jukka Rahkonen-
________________________________
Lähettäjä: mapserver-users-boun...@lists.osgeo.org
[mailto:mapserver-users-boun...@lists.osgeo.org] Puolesta Daiane Fraga
Lähetetty: 16. marraskuuta 2010 13:02
Vastaanottaja: Fuchs Juan Carlos; mapserver-users@lists.osgeo.org
Aihe: RE: RE: [mapserver-users] Gauss-Krüger
Hi,
I understand what you say. But this is not my question. I'm with a map
in a coordinate system outdated (the maps are dated from 1908). And I'm using
an application that interacts with Google Maps, which has caused problems. Did
you know how to do some kind of conversion from the Mapserver?
We can do a conversion to the WGS 1984, but it has to be done manually
for each map.
I'm not sure that may maps have a known Mapserver projection.
I'm using this:
PROJECTION
"init=epsg:26915"
"proj=latlong"
"ellps=WGS84"
"datum=WGS84"
END
Thanks!
Daiane Fraga
---------- Forwarded message ----------
From: Fuchs Juan Carlos <jf...@indec.mecon.gov.ar>
Date: 2010/11/12
Subject: RE: [mapserver-users] Gauss-Krüger
To: Daiane Fraga <daiane.a.fr...@gmail.com>
Hi Daiane
You have to find in Prij.4 the right EPSG code for your maps
in wich country / region are you interested?
yust to sart with ...
in the .map you have to insert two groups of code
in the header (first zone) goes the poyection of the map you are
producing
PROJECTION
"init=epsg:heregoesyourcode"
END
for each Layer you call to build the map
Layer
....
PROJECTION
"init=epsg:heregoesyourcodeof thesourcelayer"
END
....
end
hope it help someway
Cheers
JC
-----Mensaje original-----
De: Daiane Fraga [mailto:daiane.a.fr...@gmail.com]
Enviado el: Viernes, 12 de Noviembre de 2010 12:03 p.m.
Para: mapserver-users@lists.osgeo.org
Asunto: [mapserver-users] Gauss-Krüger
Hello,
Did someone have any problems using Mapserver with Gauss-Krüger?
I know that Mapserver is compatible with proj.4 library and the
proj.4 library supports Gauss-Krüger. But I dont know how to use it.
Somebody could help me?
Thanks.
Daiane
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