Evaluation of a sequential phase comparison data processor for laser anemometry

Measurements are presented which constitute an evaluation of a sequential phase comparison data processor operating on individual realization laser Doppler anemometer signals. The function of the processor is to carry out a continuous, discrete, 'sliding', phase comparison as each cycle is received, under an adjustable tolerance. One advantage of present processor over other similar devices is that a dropped pulse on the front end of a Doppler burst can be discarded with the system being reset in time to make a good measurement with the remaining pulses. Measurements which demonstrate duty cycle and rejection rates are presented in the paper, along with processed data compared with data reduced by visual verification.