(Peter Stickney) wrote in message ...

All Gunners hy gyroscopic lead computing sights with stadiametric
ranging. As the Gunner tracked teh target, the gyroscopes measured
the rate of movement of the target in Azimuth and Elevation, The
Gunner would also track teh target in range, by using a "Motorcycle
throttle" type grip in the sight to size a ring of dots in the sight
picture to match the airplane's wingspan. Since the wingspan of an
attacking fighter would be known, or estimated slose enough, this
would give Range and Range Rate (Closing speed) information to hte
sight.

To add to this fine explanation, starting right around the beginning
of 1945, AN/APG-15 radars started making there way in B-29s. This was
a fairly small, cheap set that took much of the guesswork for figuring
range out of the gunners hands (although they could always go back to
the manual method, especially when the radars broke down).

--
William Donzelli