A FMCW — Interferometry approach for ultrasonic flow meters

Abstract

This paper is devoted to description of the interferometry approach utilization of frequency-modulated continuous-wave (FMCW) modes in ultrasonic flowmeters. We propose the new algorithms of the time-delay difference measurement based on the phase approximation in the time domain (so called a class of Smooth Centroid Finite Difference Estimators — SCFD). Within this utilization of the beat signal model as a function of delay, it allows reduction of the signal to noise ratio (SNR) influence and the reverberation on the accuracy of estimations. This paper presents the results of the numerical and experimental modeling which prove the advantages of the proposed approach.