On 3/9/2013 1:45 PM, Jim Wilkins wrote:
"Transition wrote in message
news:955542dd-0234-410f-a0ce-
-Somebody apparently already has and invented something called
"doppler
-radar". "Doppler radar can tell when a thunderstorm has Tornado
-Vortex Signature (TVS)" I doubt you could afford one, but you may be
-able to make one of your own.

In the 70's I built a low-powered Doppler radar for about $50; they
aren't very complicated. The diode detector's output is an audio tone
proportional to the speed of the target towards or away from you, so
the faster it moves the higher the pitch. Cop speed radars use the
principle. The ~200 MPH debris in a tornado would make it scream.
http://www.advancedreceiver.com/page31.html

It gave out a really strange Boioioingggg from the reflection off and
between the steel beams when driving under a bridge. It also triggered
every radar detector around and was fun to flash at passing speeders.




Pics (or schematics), or it didn't happen.

Weather doppler is a bit tougher.
THE air mass is not a steel structure.
And it's coming at you and going away at the same time and pretty much
same speed (by comparison).