"Porky" wrote in message ...
"Bob Cain" wrote in message
...


Jim Carr wrote:
Here's a link that you tech folks can argue about:

http://www.pcavtech.com/techtalk/doppler/

What's to argue? What it all means?

Here's an observation based on intuition that I'd like
someone to dispell. Since the high frequency component is
supposed to be continuously oscilating in frequency between
two extrema, why is the spectrum at its location in the FFT
composed of peaks instead of a tabletop. Seems to me that
all values of the frequencies between those extrema should
show up and show up in equal amounts if the model everyone
talks about is valid.

I think you're right, Bob, that certainly seems logical to me. If it is
Doppler distortion, the tone should be vary in a continuous warble
from -50Hz to +50Hz because the woofer's velocity is continuously changing.

Uhm, no. Frequency modulation does *not* produce a flat tabletop.

http://www2.sfu.ca/sonic-studio/hand...odulation.html

Perhaps you both should review your basic signals & systems course
before continuing this discussion?

Ken