question on projections

Ed McNierney ed at TOPOZONE.COM
Fri Nov 12 10:19:49 EST 2004


FX -

I would first check that you are using MapServer with PROJ support for reprojection.  The "mapserv -v" command should tell you - you want to see SUPPORTS=PROJ in the output.

        - Ed

Ed McNierney
President and Chief Mapmaker
TopoZone.com / Maps a la carte, Inc.
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
ed at topozone.com
(978) 251-4242

-----Original Message-----
From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU] On Behalf Of fx gamoy
Sent: Friday, November 12, 2004 2:35 AM
To: MAPSERVER-USERS at LISTS.UMN.EDU
Subject: Re: [UMN_MAPSERVER-USERS] question on projections

Hello Franck,
In the same idea,
i ve got a set of data in WGS84. I use those datas on a gps track application.
Every layers (data and gps data) are processed in latlong WGS84 and everything works fine.

The only issue is that the map seems to be a little flattened. So i would like to output it in UTM something.
I am working in whole Europe.
I ve made many try using the projection parameter in the map section PROJECTION
  "init=epsg:xxxx"
END
but nothing occur...

Any help will be appreciated...
thanks
fx

----- Original Message -----
From: "Frank Warmerdam" <warmerdam at POBOX.COM>
To: <MAPSERVER-USERS at LISTS.UMN.EDU>
Sent: Thursday, November 11, 2004 11:26 PM
Subject: Re: [UMN_MAPSERVER-USERS] question on projections


> Chris wrote:
> > Hi everyone,
> >
> > I'm wondering how I can change from one projection to the other one
> > the
fly,
> > depending on the area of the map I'm in.
> >
> > For example, if I'm using UTM projections, and I pan from one UTM
> > zone
to
> > ther other, how can I switch my output projection let's say from UTM
> > 16
to
> > UTM 17.  It looks like I can only define one output projection in a
> > map file.
>
> Chris,
>
> This would be tricky.  You would likely need to have a bunch of
> mapscript magic to control something like this.  In "normal" use of
> MapServer, the URL will have the requested region to display in the
> URL but the region is in the coordinates of the map.  So you would
> have to do a whole bunch of preprocessing magic in a mapscript script
> to recognise that a request has wandered from one zone into another
> and transform the requested BBOX as well as overriding the mapObj coordinate system.
>
> I personally would encourage you to select a single coordinate system
> appropriate for the whole region you want to work on if at all possible.
> It would save you alot of headaches.
>
> Best regards,
> --
> ---------------------------------------+------------------------------
> ---------------------------------------+----
----
> I set the clouds in motion - turn up   | Frank Warmerdam,
warmerdam at pobox.com
> light and sound - activate the windows | http://pobox.com/~warmerdam
> and watch the world go round - Rush    | Geospatial Programmer for Rent
>



More information about the mapserver-users mailing list