Methods for Increasing the Accuracy of Geoacoustic Emission Signal Models Based on Sparse Approximation

The acoustic emission phenomenon arises due to local changes of dynamic structure of solid body. Main sources of emission are micro and macro cracks, friction and shifts. Active and passive acoustic emission methods are widely used to study the strength of materials, the landscape stability and various stages of seismic process. Geoacoustic emission is an acoustic emission of the sound range and it describes the interaction of micro and macro dislocations. Anomalies of geoacoustic signals may be earthquake precursors and they are of great interest to researchers. A typical geoacoustic signal consists of sequence of specific shape short pulses. Authors propose an additive model of geoacoustic signal. According to the model the signal decomposes into a sum of components described by the modulated Berlage and Gauss functions. The use of the matching pursuit method was offered to determine model coefficients. Unfortunately, this method has cubic computational complexity depending on number of functions on which the signal is decomposed. This article is devoted to ways to improve accuracy of the model offered by authors. Various numerical schemes allowed to increase the adaptive property of matching pursuit method with respect to geoacoustic emission signals are considered and compared.