[mapserver-users] New User - Projection Question

[Mike Boone]

Thanks for your help. Thanks to everyone else who responded too.

I finally got it working. First I had a PROJ compile problem which I worked
out, then I figured out that the lcc projection wanted EXTENTs in meters (or
something like that with large # values) for some reason, even though I had
UNITS DD defined.

At any rate my US map is now all curvy like I wanted it.

Thanks.
Mike.
mike at boonedocks.net

-----Original Message-----
From: owner-mapserver-users at lists.gis.umn.edu
[mailto:owner-mapserver-users at lists.gis.umn.edu]On Behalf Of Jeff
McKenna
Sent: Monday, July 16, 2001 1:17 PM
To: Mike Boone; mapserver-users at lists.gis.umn.edu
Subject: Re: [mapserver-users] New User - Projection Question

Hi Mike,

Although I am no expert myself when it comes to projections, I think I can
help
you (I was one of the developers involved in the Species At Risk site that
you
were looking at).
The shapefiles that you see in the Species application are all in the
Lambert
Conforml Conic (LCC) projection.  From your description of your data I would
guess that your data is in generic lat/longs (a 'Geographic' projection).  A
solution to your problem could be to specify LCC as your default projection
in
your mapfile, through a PROJECTION object, and then declare 'Geographic' as
the
layer(s) projection:

eg.


# Main map and default projection definition
#
PROJECTION
  "proj=lcc"
  "ellps=GRS80"
  "lat_0=49"
  "lon_0=-95"
  "lat_1=49"
  "lat_2=77"
END
...
LAYER
  NAME States
  DESCRIPTION "States_poly"
  TYPE POLYGON
  STATUS ON
  DATA bounds
  # Specify the data's projection
  PROJECTION
    geographic
  END
  ...
  CLASS
    ...
  END
END # Layer



Declaring 'PROJECTION geographic END' in each layer will re-project your
data to
the default projection that you specify in the PROJECTION object.
I hope this helps you, good luck.


Jeff



--------------------------
Jeff McKenna
GIS Specialist
DM Solutions Group Inc.
Ottawa, Ontario
http://www.dmsolutions.ca