Performance comparison of microtremor detection of coal mine goaf with seismic node array and DAS systems

Goaf detection is a primary challenge in the prevention and control of secondary disasters in coalfields. The precise detection of coal mine goaf has always been a crucial factor in preventing and controlling secondary disasters in coalfields. We propose a non-invasive microtremor survey-based goaf detection method and has investigated the application of seismic node array and two different distributed acoustic sensor (DAS) arrays for microtremor detection in coal mine goafs. By analyzing dispersion curves and shear wave velocity profiles, the study evaluates the performance of seismic node array and DAS arrays while also assessing the feasibility of employing DAS technology for microtremor detection in shallow buried coal mine goafs. High-density datasets, acquired using HDAS interrogation unit (IU) with a channel and point spacing of 1 meter, were processed and interpreted. The results demonstrate that the high spatial sampling rate and broad frequency bandwidth of DAS allows for the rapid acquisition of large-scale velocity structure images with high lateral resolution.