[postgis-users] Lat/lon bounding box to area?

[Paul Ramsey]

How accurate do you need your area to be? Best bet would be to treat the 
lat/lon "box" as a trapezoid (which more closely approximates its 
"ground shape"). Use distance_sphere or distance_spheroid to calculate 
the metric length of the top and bottom and the height, then basic math 
to calculate the area.

P

Steve Benzo wrote:
> Hi,
> 
> This might be a stupid question, but is there a way using PostGIS that I 
> can take a bounding box (polyline) supplied by a user (they're drawing a 
> box on the map, from which I get the xmin/ymin/etc from), which I'd like 
> to use to get an area from (utlimately acres). My first step will be to 
> get that polyline into PostGIS (struggling, but should be able to figure 
> it out) and then apply a trigger which populates an area field from 
> that. Thanks in advance.
> 
> SB
> 
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   Paul Ramsey
   Refractions Research
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   pramsey at refractions.net
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