The magic incantation to put into the great hive mind is "trilateration"

There's also another recent thread that may lead to some useful
reference... [EE]:: RF time of flight distance measurement with Arduino. -
Magic.

Some time ago (10 years perhaps) I spent some time thinking about
navigation systems for small robots. Most of the details are lost to the
fog of time, but I remember being quite surprised at how the error terms
worked out. A very small error worked out to be a fairly significant
positional uncertainty.

-Denny
--=20
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