The Seismic Camera Method for Water Leak Pinpointing

Water leakages in buried plastic pipelines pose significant challenges due to high wave attenuation, which limits the effectiveness of conventional acoustic detection methods. A widely used approach relies on the crosscorrelation of leak noise signals measured at two distinct positions along the pipeline to estimate the time delay and infer the leak location from pipe vibration data. In practice, the method may become unreliable when the propagation velocity of the leak noise or the time delay is poorly estimated, which frequently occurs in plastic pipes and heterogeneous soils. To assist correlation-based surveys, this paper presents a non-invasive leak pinpointing technique termed the Seismic Camera Method (SCM). The approach uses a mobile array of groundmounted vibration sensors combined with beamforming and seismic wave analysis to generate real-time visual maps that guide users to the leak location. The method accurately estimates the direction of arrival (DOA) of leak-induced body waves propagating to the ground surface, thereby transforming the sensor array into a directional imaging tool. Depth averaging and summing over multiple frequency bands are used to reduce errors due to grating lobes, ensuring robust leak pinpointing performance. Numerical simulations and experimental validations demonstrate that the approach reliably converges on the leak location despite uncertainties in wave speed and soil properties. The proposed methodology demonstrates the feasibility of the seismic camera concept for supporting leak surveys in plastic water distribution systems, indicating its potential to reduce search area and perhaps inspection time