Hi!

This question originates from this earlier thread:

http://lists.umn.edu/cgi-bin/wa?A2=ind0801&L=mapserver-users&D=1&T=0&P=37923

But since I learned a lot during that thread and because the thread is
full of all kinds of questions now I would like to ask a very specific
question again in a new thread.

I have also checked out the archives at this list and the PROJ list. I
have found one similar question on this list in 2005:

http://lists.umn.edu/cgi-bin/wa?A2=ind0504&L=MAPSERVER-USERS&P=R75005

Here is my question:

I have set up a mapfile with projection parameters like this:

EXTENT 10.6661 59.9155 10.6824 59.9213
PROJECTION
    "init:epsg:4326"
END

>From this mapfile I get a map over an small area in Oslo, Norway(I
cannot publish the data since the data is not free)

Then I change my map file to this:

EXTENT 37074.96 6669762.95 37982.21 6670408.60
PROJECTION
    "+proj=eqc +lat_ts=60 +lon_0=0 +x_0=0 +y_0=0 +ellps=WGS84
+datum=WGS84 +no_defs +units=m"
END

The extent is calculated by using PROJ like this:
proj "+proj=eqc +lat_ts=60 +lon_0=0 +x_0=0 +y_0=0 +ellps=WGS84
+datum=WGS84 +no_defs +units=m" < test.txt

where test.txt consists of the geographic coordinates in my first map file.

This mapfile creates a map about 18000 meters north of my first
mapfile. This is similar to the post from 2005. Longitude seems to be
correct.

I do not understand why Mapserver does not create approximatly the
same map in both map files? Is it not possible to use PROJ to convert
coordinates like this? If I set lat_ts=0 I do of course get the same
map, but that is not the projection I would like to use.

And if I cannot do it like this, how can I calculate the shift in the
y-coordinate(about 18000 meters in this example)?

Kind regards,
Espen

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