Some OP OP'ed:
>> I plan on making the mower as dumb as possible. I will have
>> my computer perform the processing and relay course and
>> direction to the mower through my wifi network or something
>> similiar (zigbee, bluetooth, etc...).

So, uh... belated reaction... Is your requirement really "Control 
mower's position with 6 inches of precision" and not "Make it mow where 
I want, but not where I don't want"?  I'm wondering if it might be 
easier to do it Roomba-style and put markers around to define where you 
*don't* want it to go, then send it on some kind of random walk that 
will generally mow about everything.
-- 
Timothy J. Weber
http://timothyweber.org
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