Detection of solid Earth excitations by laser seismo-acoustic antenna array

Abstract

The spatial and temporal distributions of seismo-acoustic wave fields are investigated. Non-stationary parameters (direction to the sources of oscillations, their intensities and localization) have been studied and estimated. The wave field distribution in elastic solid medium is recorded by the array of strain sensitive units. Every strain detector represents the laser interferometer with base-length 1-400 m, which measures the distant difference between two points of the solid medium. In this way spatial and temporal distribution of a strains field is being evaluated. The output signals of every laser sensors supplies the consequent inputs of multi-channel analog-to-digital converter and the obtained data are stored and subjected to the processing in the PC. The procedure of numerical treatment is based on the Fourier spectral analysis, which results to the tracks of non-stationary source motions to be displayed. The examples of described procedure for laser interferometers being apart up to 140 km and obtained data are presented.