Geophysical research: article

Аnnotation: The work is devoted to the development of methods and algorithms for automatic detection of useful signals in a noisy environment on the records of infrasonic groups. Overview of the most common methods for processing infrasonic signals is given. A set of algorithms and the sequence of their application for the rapid detection of infrasonic signals on the records of infrasonic groups, implemented in the form of automatic detector, are described. The performance of the described detector is achieved by optimizing the calculations and by preliminary calculation of some of the parameters for infrasonic groups consisting of three sensors. The relevance of the use of fast algorithms for the detection of target signals is dictated by a number of applied problems for the rapid detection of places where infrasonic signals are generated, for example, when searching for spent elements of launch vehicles or monitoring avalanche-prone slopes in mountainous areas. The automatic detector described in the work evaluates a number of standard parameters of the detected acoustic signals, such as source azimuth, angles of incidence of infrasonic waves, and apparent velocities. Additionally, algorithms for estimating the duration of the recorded signals and variability of the source azimuth are implemented. The last two parameters are used to automatically detect moving sources of infrasonic emissions. The testing of the application of the described detector in the near-real time mode was carried out within the framework of experimental work on infrasonic monitoring of avalanche activity on the Kamchatka Peninsula in February-April 2020. The results of using the detector showed a high reliability of the obtained solutions. Automatically detected signals and associated with avalanche manifestations were verified by visual inspection of the area.