An Improved Positioning Algorithm With High Precision for Dual Mach–Zehnder Interferometry Disturbance Sensing System

An improved positioning algorithm for dual Mach–Zehnder interferometry (DMZI) disturbance sensing system is proposed. We employ zero-crossing method, which can be computed easily to extract the disturbance signal segment with maximum zero-crossing rate. Meanwhile, we use general cross correlation based on Wiener filtering and $G_{\rm nn}$ subtraction weighting function (WG-GCC) to estimate the time delay of the extracted signal, which is robust to the correlated noise. Finally, we experimentally demonstrate that the proposed positioning algorithm can greatly improve the positioning accuracy with positioning error of ±20 m. Compared with the traditional positioning algorithm, the positioning error has been reduced by an order of magnitude. This algorithm has a promising potential in real-time fence perimeter applications.