High precision location of micro-seismic sources in underground coal mine

Accurate location of micro-seismic sources in underground coal mine has great significance for monitoring and early warning of dynamic disaster. Micro-seismic source information is generally extracted through inversion of the data acquired by the underground sensors. The installation of the sensors is limited around underground roadway. The seismic location precision will be greatly decreased in the case of unreasonable arrangement of sensors along the roadway and approximately in a plane. As for the ill-posed problems caused by the inversion for source location with sensor-received information, high precision location algorithm of micro-seismic source based on monitoring pbints arrangement optimization is presented in this paper. Firstly, the ill-posed problems are judged by calculating the coefficient matrix condition numbers. The ill-posed matrix is then pretreated by centralization and row balance jointly. The regularization parameters of pretreated matrix A and b are calculated by the L-curve method. The seismic source coordinates regularization solution is obtained using Tikhonov regularization algorithm. The results show that the matrix magnitude is decreased effectively with centralization method, ill-posed condition numbers are reduced with row balance pretreatment. The minimum seismic source coordinate error of Tikhonov regularization solution after pretreatment is 3. 09 m, and is greatly decreased compared to the error by Gaussian elimination solution before pretreatment. High precision seismic source location is realized in limited space of underground roadway by means of the above optimization processing.