SPECTRAL ESTIMATIONS USING LASER DOPPLER VELOCIMETRY WITH AND WITHOUT BRAGG CELL FREQUENCY SHIFTING

摘要

Experimental tests were conducted to demonstrate that laser Doppler velocimetry Bragg cell noise corrupts estimates of the flow variance, the autocovariance function and the power spectral density, particularly in low turbulence flows. A method for removing this noise from LDV measurements using knowledge of the autocovariance function is described. Finally, a discussion of how this noise affects the power spectral density is given.