[Proj] Middle Europe projection setup problem
Mikael.Rittri at carmenta.com
Wed Feb 23 10:50:59 EST 2011
If I understand you right, I think your problem is just that longlat
(or Plate Carrée) isn't a good projection for map display (except near
the equator). Longlat will show one degree of longitude to be as long
as one degree of latitude, but since the meridians approach each other
away from the equator (and meet at the poles), that's not true in general.
At the latitude of Budapest, one degree of longitude is about 75 km,
but one degree of latitude is about 111 km.
Perhaps you can try using
<Layer srs="+proj=utm +zone=34 +ellps=WGS84 +datum=WGS84 +no_defs">
From: proj-bounces at lists.maptools.org [mailto:proj-bounces at lists.maptools.org] On Behalf Of Tamas Janovics
Sent: den 23 februari 2011 12:10
To: proj at lists.maptools.org
Subject: [Proj] Middle Europe projection setup problem
I use Mapnik with openlayers and postgis database. I have an osm map
from hungary and another hungary map in the postgis/postgresql
When I visualize the maps in my browser i get the following
maps/pictures. See below:
Hungary OSM map:http://img14.imageshack.us/img14/4318/hungaryosm.png
My other Hungary map:http://img7.imageshack.us/img7/2817/hungaryroad.png
My problem is that the projection isn't good enough, because Hungary is "thicker" or "higher". My map (not the osm map) is in WGS84 projection, and I use this in my mapfile:
<Map srs="+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs"
<Layer srs="+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs">
I think that the view center of my map is by the 0.0 (lat) and 0.0 (lon) coordinates, that's why my maps are "thinner" than on other maps.
Is that really my problem? What should i change in my settings?
Thank you for your help!
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