Sweet! It must do on-the-fly projections under the covers, right? That's a huge improvement since I used PostGIS last time.
On Jul 7, 2010, at 11:40 AM, Paul Ramsey wrote: > David, > > Consider using the GEOGRAPHY type if your queries are just going to be > ST_DWithin style. That will remove all projection issues. > > P. > > On Wed, Jul 7, 2010 at 11:19 AM, David Jantzen <[email protected]> wrote: >> Hey All, >> >> It's been a couple years but happily I have a reason to work with PostGIS >> again! I'm rusty, and this is pretty a basic question, so if you just >> specify the chapter in TFM I'll happily go read it. >> >> I need to do simple point-and-radius searches for some properties in >> Germany. Very soon I'll need to do this same thing across Europe and North >> America, and some in Asia. My understanding is that the accuracy of such >> measurements will degrade as I use projections covering larger and larger >> geographical areas. >> >> So, some questions: >> 1) Is there a single global projection that I could use for all such >> calculations? How bad would the distortions be and where? >> 2) Assuming the correct path is to switch projections depending on area of >> focus, what are some strategies for this kind of dynamic switching in SQL >> queries? >> >> Thanks for your help (and patience), >> David >> _______________________________________________ >> postgis-users mailing list >> [email protected] >> http://postgis.refractions.net/mailman/listinfo/postgis-users >> > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
