[aprssig] Clarification of Ambiguity in APRS

Robert Bruninga bruninga at usna.edu
Tue Jan 8 15:10:53 EST 2008

>> I still don't like polygons.  These Boxes 
>> drawn exactly on a LAT/LONG grid imply a 
>> precise boundary of ambiguity which is
>> totally missleading and of drastically 
>> differrent sizes from the equator to the 
>> poles.  They just convey the wrong information
> It's nice that APRSdos wants to show ambiguity 
> with a circle, but I disagree that a line curved 
> into a circle implies anything different 
> that a line formed into a box *ON THE FACE OF IT*. 
> Now, since you say the amb. circle is a 
> representation of something not known, that is 
> fine as it is documented.

Yes, that is the main point.  It was intended to be "by
definition" so that all clients and users would have the same
interpretation.  As long as we have a consistent definition that
everyone understands the same way, then everyone will know what
the circle means.

I just checked and to my surprise, ambiguity is not obviously
clarified in my APRS1.1 addendum.  But it is under the link
there under Symbol Attributes:


I suppose since this debate comes up annually or so, I should
prepare a specific document just for Ambiguity for final


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