> > Or the other way around. =A0Have the copter emit pulses and multiple re=
ceivers
> > scattered around at known fixed locations pick up the pulses and a mast=
er
> > processing system compares the received times to find position. =A0Ultr=
asound
> > should work for this.
>=20
> Yes, as far as I remember the concept is similar to old "Method for
> determining artillery position". The problem can be reflections from
> walls and other surfaces.

I believe it is also used these days to locate gunfire in American cities. =
I am not sure why microphones exist on lampposts at intersections (they may=
 have been installed for this purpose) but someone had the bright idea to u=
se receiving time differences of gunshots to locate just where they origina=
te from.
--=20
Scanned by iCritical.

--=20
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