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List:       postgis-users
Subject:    Re: [postgis-users] Geodetic Support
From:       Paul Ramsey <pramsey () refractions ! net>
Date:       2007-06-27 16:29:43
Message-ID: 46829077.6070801 () refractions ! net
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Speaking of which, the more I think about it, the more I like 
Microsoft's "solution" to the problem of supporting both planar and 
polar coordinates, which is to just declare the one problem to be two 
problems, with both a "geometry" (planar) and a "geography" (polar) 
type.  Means you don't have to do SRID lookups to figure out if you are 
geodetic or not, you can have completely different index types without 
any sort of magic switches hiding in the backend, etc.  Really cleans up 
a lot of things.

P

Paul Ramsey wrote:
> There are definitely issues with dateline and poles when working in 
> 4326, since the coordinates are treated as planar, not polar. 
> Workarounds for the dateline are relatively easy to do, usually in the 
> form of double-entry inserts (we should probably write a standard 
> trigger for doing that (if something crosses the dateline, insert it 
> twice, once on each side of the plane)).  The poles I think are a harder 
> problem.
> 

   Paul Ramsey
   Refractions Research
   http://www.refractions.net
   pramsey@refractions.net
   Phone: 250-383-3022
   Cell: 250-885-0632
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