[chbot] Differential GPS

[Robin Gilks]

Greetings all

I'm just mulling over ideas for a walnut picker-upper and one of the
requirements will be accurate positioning to make sure that I don't run
into trees or irrigation nozzles. I think that if I can get below 0.5m
accuracy within 300m of a fixed reference then it would be doable.

Does anyone have information on such a system, perhaps transmitting in the
433MHz ISM band at very low power.

TAPR did have one but the Motorola Oncore VP OEM GPS receiver they used is
no longer available so it looks like the whole project is dead.

I'm sure with the cheap GPS receivers available now there must be
something available that can lock to a defined set of birds so that mobile
and static receivers look at the same ones and correction information can
be sent at a low rate from the static to the mobile station.

Thoughts appreciated...

-- 
Robin Gilks