# Microseismic Electronic Fencing for Monitoring of Transboundary Mining in Mines
## 2 Factors Affecting Localization Accuracy
### Analysis of Observing Systems  
Microseismic observation systems consisting of different sensor arrangements have a large impact on the localization accuracy, which is due to the different localization ranges focused by different observation systems. For transboundary microseismic monitoring in mines, we propose a nested observation system with well-ground association (Figure 2d,e), which is different from the general observation system with sensors arranged in the roadway for the daily monitoring of mining (Figure 2a), and consists of sensors on the ground and sensors inside the wells. The ground sensors are organized into a large circle located at the edge of the measurement area and a smaller circle situated within it, thus creating a nested configuration. Figure 2 illustrates five types of observation systems. The following sections provide a comparative analysis of the accuracy of these five observation systems in locating microseismic events around the mine boundary. \begin{table}
\begin{tabular}{c c c c c c c c} \hline
**Event** & \(\mathbf{X_{0}}\) & \(\mathbf{Y_{0}}\) & \(\mathbf{Z_{0}}\) & **Method** & \(\mathbf{X}\) & \(\mathbf{Y}\) & \(\mathbf{Z}\) & **Location Error** \\ \hline  & 750.000 & 400.000 & 200.000 & Grid & 750.000 & 398.440 & 199.220 & 1.744 \\ \(1\) & 750.000 & 400.000 & 200.000 & Simplex & 749.770 & 398.750 & 199.260 & 1.471 \\  & 750.000 & 400.000 & 200.000 & Geiger & None & None & None & Unable locate \\ \hline  & 750.000 & 300.000 & 200.000 & Grid & 750.000 & 299.220 & 198.440 & 1.744 \\ \(2\) & 750.000 & 300.000 & 200.000 & Simplex & 749.920 & 299.290 & 198.610 & 1.563 \\  & 750.000 & 300.000 & 200.000 & Geiger & 752.730 & 224.210 & 84.740 & 137.973 \\ \hline  & 750.000 & 200.000 & 200.000 & Grid & 750.000 & 198.440 & 199.220 & 1.744 \\ \(3\) & 750.000 & 200.000 & 200.000 & Simplex & 750.260 & 198.030 & 198.490 & 2.496 \\  & 750.000 & 200.000 & 200.000 & Geiger & 750.020 & 11.530 & 349.310 & 240.446 \\ \hline  & 200.000 & 400.000 & 200.000 & Grid & 200.780 & 400.780 & 202.340 & 2.587 \\ \(4\) & 200.000 & 400.000 & 200.000 & Simplex & 200.600 & 400.680 & 202.290 & 2.463 \\  & 200.000 & 400.000 & 200.000 & Geiger & 267.590 & 499.340 & 222.340 & 122.213 \\ \hline  & 500.000 & 700.000 & 200.000 & Grid & 499.220 & 699.220 & 199.220 & 1.351 \\ \(5\) & 500.000 & 700.000 & 200.000 & Simplex & 499.540 & 699.190 & 199.060 & 1.323 \\  & 500.000 & 700.000 & 200.000 & Geiger & 365.160 & 615.270 & 124.190 & 176.375 \\ \hline  & 750.000 & 750.000 & 200.000 & Grid & 750.000 & 750.000 & 200.000 & 0.000 \\ \(6\) & 750.000 & 750.000 & 200.000 & Simplex & 749.900 & 750.300 & 199.940 & 0.322 \\  & 750.000 & 750.000 & 200.000 & Geiger & 662.020 & 671.860 & 552.030 & 371.176 \\ \hline \end{tabular}
\end{table} 
Table 1: Localization results of the three localization methods (Unit: m). 3 (750, 200, 200)) that were near the boundary of the ore body were localized using the five arrangements, and the results of the localization are shown in Figure 3. To reduce the error caused by picking up the first arrival time, the results in Figure 3a are shown after five repetitive localizations for each of the three events for each observing system. Figure 3b shows that the average errors of the circular observation system in the horizontal and depth directions are 5.118 m and 12.550 m, respectively, which are the largest among the five observation systems. The error in the horizontal direction is 9.979 m for the observation system with sensors laid along the roadway, and the error in the depth direction is the smallest, mainly because the sensor settings are located at the same level as the seismic source. The average error of the regular arrangement observation system is 0.802 m in the horizontal direction and 3.561 m in the depth direction.