[postgis-users] spherical calculations in PostGIS

[Jérôme Vuibert]

If you get informations about this, i would be interested in getting them, 
as i am currently evaluating PostGIS

Sincerely.

Jerome
----- Original Message ----- 
From: "Bruce Raup" <braup at nsidc.org>
To: <postgis-users at postgis.refractions.net>
Sent: Wednesday, September 22, 2004 12:01 AM
Subject: [postgis-users] spherical calculations in PostGIS


> Hello PostGIS users and developers,
>
> What is the status of how spatial calculations are done (planar vs.
> spherical) within PostGIS?  I have searched the archives of this list, and
> found a message from Dave Blasby from 2001
> (http://postgis.refractions.net/pipermail/postgis-users/2001-September/000331.html)
> wherein Dave asked, "does anyone know of any open source software 
> libraries
> for doing calculations on an ellipse?"  Was one found?
>
> I see that there is a function "distance_spheroid", but what about the
> spatial operators such as &&?  If your data coordinates are geodetic
> (lon/lat), is there a way to make the operators operate on the sphere?  I
> don't need them to operate on the ellipsoid -- the sphere is good enough.
> But I work with large (continental scale) areas, so the plane is not good
> enough.
>
> If a spherical calculation package hasn't been found, then one developed 
> at
> my institute (National Snow and Ice Data Center) may be of use.  See
> http://nsidc.org/data/tools/spheres/
>
> It's written in Java, but much of it has already been ported to C.
>
> Thanks,
> Bruce
>
> -- 
> Bruce Raup                                               Phone: 
> 303-492-8814
> National Snow and Ice Data Center, U. of Colorado, 449 UCB, Boulder, CO 
> 80309
> http://cires.colorado.edu/~braup/
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