Which of the following statement about Doppler is most correct?
A. non-directional Doppler uses phase-singular processing, while bi-directional Doppler uses phase-quadrature processing
B. non-directional Doppler uses FFT processing, while bi-directional Doppler uses Nyquist processing
C. non-directional Doppler uses autocorrelation processing, while bi-directional Doppler uses phase-quadrature processing
D. non-directional Doppler uses phase-quadrature processing, while bi-directional Doppler uses coherent processing
E. non-directional Doppler uses non-coherent processing, while bi-directional Doppler uses phase-quadrature processing.
