[Geowanking] bounding points in lat/lon

[Daniel Smith]

At 4:18 PM -0400 4/16/03, VTP wrote:
>Maybe i'm missing something here.  If i understand, you want the database to
>do the comparison for you, but it's not a spatially-aware database.


Not necessarily.  I'm still at the point of figuring out
the bounding box around a point...

>
>
>1. Convert your Latlon to UTM
>2. add/subtract the desired distance from the UTM point (linear meters,
>NSEW)
>3. Convert the 4 points back to Latlon
>4. Use the extents of those 4 points to do your SQL query

Worth a look.  thanks!

Thanks Joshua for the PostGIS ref, and the insane
SQL statement (is this what you are doing in GeoURL?)

I just discovered http://www.freegis.org/ ...

Daniel

-- 
Daniel L. Smith - Sonoma County, CA - AIM: SonomaDaniel
JavaJoint.com   - daniel.org        - ThereAndThen.org