Digital Calibration Procedure for Laser Doppler Velocimetry in Acoustics

This paper propose a digital calibration procedure for errors compensation of the output signals of an analogical Quadrature Demodulation (QD) hardware. This kind of device is used for Laser Doppler Velocimetry (LDV) measurements in acoustics. The method developed is based on the use of a Maximum Likelihood Estimator (MLE) in order to estimate the amplitudes, the tension offsets, and the phase shift of two quadrature signals. Such a technique provides a good and a simple way for QD calibration.