Cross-spectral phase method for time delay estimation in acoustic leak detection

This paper introduces a method for estimating time delays in acoustic/vibration leak signals within water distribution systems, using linear segmentation of the cross-spectral phase. The method applies linear regression to undistorted regions of the phase, automatically identified by a simple algorithm, to calculate the time delay. Simulation and experimental results demonstrate that the method accurately estimates time delays without the need for pre-filtering, even in the presence of multiplicative noise that distorts the cross-spectral phase—offering a significant improvement over correlation-based techniques. Furthermore, the method provides a confidence interval that quantifies the uncertainty in the estimated leak location, thereby enhancing the reliability of leak localisation.