[postgis-users] Confusing Distance

sub3 steve at subwest.com
Wed Dec 17 12:34:43 PST 2008


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.

-- 
View this message in context: http://www.nabble.com/Confusing-Distance-tp21060820p21060820.html
Sent from the PostGIS - User mailing list archive at Nabble.com.




More information about the postgis-users mailing list