The Ghost wrote:

Bob Cain wrote in message ...

fd = f*c/(c + v),

Randy, that equation is only defined for a static v.


You say that with such authority, but you most certainly don't have
the authority required to make such a bold assertion. Can you
provide a reference to the technical literature to support such a
claim? The answer is no, because no such reference exists. The fact
of the matter is that your assertion is nothing more than a personal
belief, which you have accepted without questioning its validity.
Had you looked into it, as I have, you would have discovered that the
equation applies under both constant velocity and dynamic velocity
conditions. You will find the derivation in Allan Pierce's book
entitled "Acoustics: An Introduction to Its Physical Principles and
Applications."

To be more precise it says on page 453, "The source does not
have to be traveling with constant velocity or in a straight
line for Eq. (5) to apply; however, determination of the
point on trajectory from which the wavelet originates
requires additional labor to match the kinematics, possibly
a graphical solution if the motion is not rectilinear."

I would add "and not constant."

He disqualifies the whole section for direct application to
a local analysis of a superimposed HF and LF signal in the
third sentence of the section. I'll leave it as an exercise
for the student to figure out what is wrong with the way fd
= f*c/(c + v) has been applied to that analysis. For now
that is. :-)


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein