yes, any em wave will be shifted in frequency/wavelength when there is a
relative velocity between the tx and rx.

doppler shift is NOT 'a tone frequency'. it may be heard as a tone in a
receiver if you beat it against a fixed local oscillator. But the doppler
shift does not modulate the wave or change the type of modulation that may
already be imposed on the wave by the transmitter.

now if you are talking about a doppler direction finder system... those work
best with unmodulated signals, but will work with modulated signals but may
have difficulty getting reliable directions, especially if the modulation
frequency is near the rotational frequency of the array.


"mazerom" wrote in message
oups.com...
the doppler shift is fundamentally a tone frequency brought about by a
continuous wave source moving in and out. is it possible to have
reliable doppler shift when our source is spread spectrum or say some
form of digital modulation?