[uf-discuss] Geo precision (was: hCard multiple locations)

Andy Mabbett andy at pigsonthewing.org.uk
Sat Aug 25 02:28:36 PDT 2007

In message 
<73766b160708241616j7a13fc7bnde57e741041e07b9 at mail.gmail.com>, Kevin 
Marks <kevinmarks at gmail.com> writes

 >The longitude and latitude values MUST be specified as decimal degrees
 >and should be specified to six decimal places.

That's interesting; it's clearly not suitable when giving the 
coordinates for very large sites like a county or a park, where 
precision to 1 metre is unwarranted; nor for giving very precise 
coordinates for, say, the location of the camera taking a picture of a 
single flower or insect. It's certainly not what's used in practice.

Perhaps the Geo spec, and those of the other microformats which use it, 
should allow fewer or more decimal places, and require parsers to 
convert to six places when exporting as a vCard? Or perhaps a revision 
to the vCard spec is required?

The spec does, though, emphasise the points I've always made; the number 
of decimal place for latitude and longitude should be equal; and 
trailing zeroes are significant.

Andy Mabbett

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