On Mon, 10 Oct 2005 22:04:02 +0100, david@djwhome.demon.co.uk (David
Woolley) wrote:

What you also have yet to account for is that the signal is reflected from
many different ranges so is convoluted in time by the distribution of
reflector by range. 

Since the lunar orbit is an ellipse and not a perfect circle, the
orbital speed is not constant, but the lunar rotation speed is
constant, the moon does not turn exactly the same side towards the
earth. Due to libration, about 55 % lunar surface can be seen from
earth, when making observations at different times of the month.

Due to the libration "rotation", when the signal is reflected from
various places all around the lunar disk, some signals will be
reflected with a positive doppler, while other signals from the
opposite part of the moon will have a negative doppler. This libration
fading will spread out even a constant frequency carrier. CW (Morse)
signals sometimes sound quite funny and are hard to read. 

Paul