Algorithms for Automatic Detection and Location of Infrasound Events in the PSDL System

The paper presents a description of an automated system and the algorithms implemented in it for detection, association and location of low-frequency acoustic events based on infrasound array data. An algorithm for detecting infrasound signals by calculating the cross-correlation function between records of individual sensors in a array is described. The implemented algorithm is optimized for working with arrays consisting of a large number of sensors, which allows minimizing the computational load on the monitoring system in near-real time mode. A procedure for recognizing long-term signals with a source position that may change over time, such as moving vehicles or snow avalanches, is described. The paper also describes algorithms for associating infrasound signals recorded by different arrays, as well as locating a signal source based on data from several infrasound arrays. The system is capable of simultaneously analyzing seismic and infrasound monitoring data and detecting pairs of two types of signals associated with a common source. The algorithm for such an association is also given in the paper. The described system of automatic detection and location of infrasound signals can be used for monitoring dangerous natural and man-made processes and phenomena in a mode close to real time.