Multiphase pipe flow velocity measurement in strong colored noisy Doppler ultrasound : parametric and non parametric approaches

Real time flow velocity measurement is a problem of considerable practical interest in industrial and biomedical applications. Due to their good frequency resolution, parametric methods such as recursive least squares or their variants are commonly used in such cases. However, some typical problems of these methods, namely correct order selection and fitness of the parametric model, may alter the accuracy of the frequency estimates. This paper provides comparison between specific Instrumental Variable (IV) identification which simultaneously gives model parameters and orders, and different non parametric time-frequency estimators. Results of tests on modelled Doppler signals with known flow velocity profile, are discussed.