Sensitivity analysis of microseismic positioning accuracy based on distribution models of influencing factors

Based on microseismic positioning equation and minimum error principle, an input and output mathematical model for evaluating sensitivity of microseismic positioning accuracy was constructed. Distance error between microseismic sources and sensors, seismic wave velocity error and trigger times error were selected as analysis factors. Factor distribution fanction was discussed by using information entropy, and the corresponding expression was obtained by functional variation. Scheme of 16 groups was designed by using orthogonal method. Level value of each factor was given according to the factor distribution function. And the global sensitivity analysis was performed. The results show that three factors accord with uniform distribution in a given interval; for both the internal and external field sources, seismic wave velocity error is the most influential factor that affects the positioning results, and the significant order from big to small of influence on positioning accuracy is Ve, Te and De. For internal field source, all three factors have some significant influence on positioning accuracy; while for the external field source, only the seismic wave velocity error has some significant influence on positioning accuracy, which may probably be affected by the interaction between the factors or experimental errors. The research conclusions may offer specific guidance for the accurate location analysis of microseismic monitoring in the similar projects. © 2015, Central South University of Technology. All right reserved.