Dumb question : the signification of SRS?

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Dumb question : the signification of SRS?

Adrien Anselme
Hello,

As it is an optional argument when sending requests, I never really
cared about SRS. But what is it exactly? I did some googling but found
so much different definitions that I don't know what's the truth...

Thanks for your help :)

--
Adrien


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Re: Dumb question : the signification of SRS?

Chris Holmes-2
Sorry for the late response, this got lost in the vacation shuffle.  
First, there's no such thing as a dumb question.  I've worked on this
stuff for a while now, and I feel I still don't really understand srses.  
Basically it has to do with the fact that the earth is round and maps are
flat.  So you have to warp the image in some way, using like matrix
transformations and whatnot.  This is why greenland generally looks about
15 times the size of DRC, when they're actually about the same size.

So GIS data is always stored in a particular projection, generally
countries have one or a few projections that are good for their area of
the world, that they keep their data in.  You get into problems when
you're combining data, which is one of the biggest uses ofa WMS.  So they
allow you to specify if you want it in a different srs from the one that
it's stored in, and if the server can, it will do the transformation of
coordinates for you.  

Does this make sense?  And could someone who knows more than me please
correct me if I'm wrong about it all?

Chris

On Mon, 27 Jun 2005, Adrien Anselme wrote:

> Hello,
>
> As it is an optional argument when sending requests, I never really
> cared about SRS. But what is it exactly? I did some googling but found
> so much different definitions that I don't know what's the truth...
>
> Thanks for your help :)
>
> --
> Adrien
>
>
> -------------------------------------------------------
> SF.Net email is sponsored by: Discover Easy Linux Migration Strategies
> from IBM. Find simple to follow Roadmaps, straightforward articles,
> informative Webcasts and more! Get everything you need to get up to
> speed, fast. <a href="http://ads.osdn.com/?ad_idt77&alloc_id492&op=click">http://ads.osdn.com/?ad_idt77&alloc_id492&op=click
> _______________________________________________
> Geoserver-users mailing list
> [hidden email]
> https://lists.sourceforge.net/lists/listinfo/geoserver-users
>

--



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