[postgis-users] Confusing Distance

[David William Bitner]

How did you chose to use 32661?  You should use an SRID that uses a
projection that works well for the area that you are working in.

On Wed, Dec 17, 2008 at 2:34 PM, sub3 <steve at subwest.com> wrote:

>
> Hi,
> I was trying to calculate the distance (in NM) from two points.  I've found
> a method using distance_spheroid, but I am curious why my original method
> didn't work correctly:
>
> select distance (
>  transform( GeomFromText('Point(-76.29145663 -45.9229366415 )', 4269),
> 32661),
>  transform( GeomFromText('Point(-76.42922377 -45.2098919078 )', 4269),
> 32661)
> ) / 1852
>
> gives me 297 NM, but it is really a lot closer.  I thought distance() would
> return the number of meters, then I divide by the number of meters in a NM.
>
> Thanks for any help.
>
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-- 
************************************
David William Bitner
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