[NEWBIE] Using Mapserver and PROJECTION

[Frank Warmerdam]

On 6/26/05, François TOURDE <fr-ms at tourde.org> wrote:
> Hi the list.
> 
> I'm a newbie using mapserver, and in geodata. :( ... I've a probably
> simple problem using the image output:
> 
> On my .MAP file, I have the following lines:
> 
> # Mode latlong
>   EXTENT 2.8830 42.683 7.5 43.950 # Geographic
>   PROJECTION "init=epsg:4326" END
>   UNITS DD
> 
> All my layers have no PROJECTION infos.
> 
> When I replace the above lines by:
> 
> # mode Collignon
>   EXTENT 205512.50       4889370.83 521106.75       5051672.48
>   PROJECTION
>    "proj=collg"
>   END
>   UNITS METERS
> 
> the image is ... blank. No coast lines, no features, etc...
> 
> Could you point me the problem?

François,

It could be a number of things, but your bounds do seem reasonable.
I would suggest adding an explicit ellipse definition:

PROJECTION
  "proj=collg"
  "ellps=WGS84"
END

Use normal debugging techniques.  For instance, check
your error log, try rendering with shp2img, as that can provide
better feedback.  Turn on debugging.  etc.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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