[postgis-users] ST_DWithin with radius 0.000001

[Charles Galpin]

On May 25, 2010, at 5:43 AM, nguyen liem wrote:

> One more question, if i would like to use ST_DWithin in projection WGS84 and the radius is in 1 meter, how to do that?

As someone else said it depends on the latitude you are dealing with, but you take the circumference of the earth at your location and divide by 360 to get one degree. So at the equator one degree is roughly 69 miles or 111km.  So 0.00001 is 1m at the equator (but is .8m in NJ for example).

hth,
charles