Observation And Study Of Low-Frequency Atmospheric Infrasonic Waves Based On Wide-Spread Sensor Network Array

Using a wide-spread sensor network array, atmospheric infrasound has been monitored for a long time. Low-frequency atmospheric infrasonic waves, according to continuous observations and statistic analyses, which closely related with nature event, have been studied in this paper.Through setting infrasound microphone in wide-area, radiated infrasonic waves can be better received and used. The basic data acquisition unit is absolute infrasound microphone InSYS2008 & multiple channel digitizer InSYS2008. Basing on the 16 channel standard checking arrangement, proposed accurate calibration method for batch processing, and realized compensation function data fixing. On the other hand,16 bit high-precision sample and GPS synchronous calibration reduced acquisition error, and improve the accuracy of data. For information analysis and features extraction, waveforms, spectra, time-frequency charts and correlations of these infrasonic waves among sensors have been studied. Results show that the precursory infrasonic waves have good regularities, which occur either in one group or intermittently in several groups with frequencies in a range of 0.001 Hz-0.02Hz and amplitudes in a range of 30Pa-200Pa, etc, and have high SNR. In addition, infrasonic signal processing software is designed using MATLAB. Through the user interface operating, signal analysis can be realized conveniently.This topic research is beneficial to the development of infrasonic signal array detection and processing technology. As such kind of infrasonic wave was usually observed repeatedly several days before strong earthquakes. The results provided in this paper may propel the study of atmospheric infrasonic waves and the correlations with natural events, especially with earthquakes.