Analysis of the Degradation in Source Location Accuracy in the Presence of Sensor Location Error

The deviation of microseismic station location will affect the microseismic source location accuracy in microseismic monitoring. The relationship between microseismic station location deviation and source location accuracy is studied in the paper. A global optimization algorithm, particle swarm optimization (PSO), is used to search for the source location. Results show that PSO method is good. The source location error increases with the microseismic station location error. The relationship between them is nonlinear. The microseismic sources outside the microseismic station array are more sensitive to the microseismic station location deviation than inside the microseismic station array. The bigger the microseismic station location error, the greater the difference. Therefore, when the microseismic source is outside the microseismic station array, it is more necessary to ensure the accuracy of microseismic station location.

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Study on Optimization of the Number of DF Stations

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.709.485 ◽

2014 ◽

Vol 709 ◽

pp. 485-490

Author(s):

Xiang Wu ◽

Jun Jun Zong ◽

Xun Xue Cui ◽

Chuan Xu Liu

Keyword(s):

Maximum Likelihood ◽

Maximum Likelihood Estimation ◽

Likelihood Estimation ◽

Direction Finding ◽

Location Error ◽

Location Accuracy ◽

Error Models ◽

Reasonable Number ◽

Simulation Results

Reasonable number of direction finding station is examined in multi-station bearing-crossing location. Though it is believed that increasing the number of station is helpful to improve the location accuracy, In the paper, the maximum likelihood estimation (MLE) as an example. The algorithms and the location error models are given. The simulation results show that the location accuracy will be improved quickly with the increase of the number of the measuring participants, but the improvement will be sharply slowed down if too many station involved, which also boost the complexity of location.

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An at-sea assessment of Argos location accuracy for three species of large whales, and the effect of deep-diving behavior on location error

Animal Biotelemetry ◽

10.1186/s40317-020-00207-x ◽

2020 ◽

Vol 8 (1) ◽

Author(s):

Ladd M. Irvine ◽

Martha H. Winsor ◽

Tomas M. Follett ◽

Bruce R. Mate ◽

Daniel M. Palacios

Keyword(s):

Diving Behavior ◽

Location Error ◽

Location Accuracy ◽

Deep Diving

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Mechanisms of array geometry in the control of AE/MS source location accuracy

International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts ◽

10.1016/0148-9062(89)92643-0 ◽

1989 ◽

Vol 26 (3-4) ◽

pp. A190

Keyword(s):

Source Location ◽

Location Accuracy ◽

Array Geometry

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Artificial Seismic Source Field Research on the Impact of the Number and Layout of Stations on the Microseismic Location Error of Mines

Advances in Civil Engineering ◽

10.1155/2019/1487486 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Bao-xin Jia ◽

Lin-li Zhou ◽

Yi-shan Pan ◽

Hao Chen

Keyword(s):

Wave Velocity ◽

Monitoring Network ◽

Seismic Source ◽

Source Location ◽

Location Model ◽

Location Error ◽

Monitoring Cost ◽

Microseismic Location ◽

Seismic Source Location ◽

The Impact

A site experiment is performed herein within a 100 m range using a high-frequency structure activity monitor to explore the impact of different factors on the microseismic source location and analyze the range of influence of the velocity model, number of stations, and array surface on the seismic source location. Moreover, the impact of wave velocity, velocity-free location algorithm, and position of the seismic source on the microseismic location error of mines is discussed by establishing the ideal theoretical model of the wave velocity location and with particle swarm optimization. The impact of the number of stations and tables on the location precision is also explored by using the microseismic signals produced by the artificial seismic source. The results show that, for the location model containing the velocity, the velocity error would greatly affect the location precision, and the velocity-free algorithm receives good location results. The location result is more satisfactory when the seismic source point falls in between array envelope lines. The seismic source location precision is in direct proportion to the number of stations. According to the experiment, within a 100 m range, when the number of stations is over 12, the effect does not significantly grow with the increase of stations; the number of tables affects the location precision; and the multitable location effect is significantly superior to the single-table effect. The research shows that the optimal station density is 0.0192%, and the appropriate sensor layout to form a multitable monitoring network may effectively enhance the microseismic source precision of mines through the selection of a velocity-free location model. On the contrary, the number of stations can be reduced on the premise of the allowable error of the seismic source location, which may effectively reduce the monitoring cost.

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Sensitivity maps for time-reverse imaging: an accuracy study for the Los Humeros Geothermal Field (Mexico)

Geophysical Journal International ◽

10.1093/gji/ggaa160 ◽

2020 ◽

Vol 222 (1) ◽

pp. 231-246

Author(s):

C Finger ◽

E H Saenger

Keyword(s):

A Priori ◽

Velocity Model ◽

Source Location ◽

Geothermal Field ◽

Location Accuracy ◽

Accurate Localization ◽

Localization Scheme ◽

Priori Information ◽

Initial Source ◽

Sensitivity Maps

SUMMARY The estimation of the source–location accuracy of microseismic events in reservoirs is of significant importance. Time-reverse imaging (TRI) provides a highly accurate localization scheme to locate events by time-reversing the recorded full wavefield and back propagating it through a velocity model. So far, the influence of the station geometry and the velocity model on the source–location accuracy is not well known. Therefore, sensitivity maps are developed using the geothermal site of Los Humeros in Mexico to evaluate the spatial variability of the source–location accuracy. Sensitivity maps are created with an assumed gradient velocity model with a constant vp–vs ratio and with a realistic velocity model for the region of Los Humeros. The positions of 27 stations deployed in Los Humeros from September 2017 to September 2018 are used as surface receivers. An automatic localization scheme is proposed that does not rely on any a priori information about the sources and thus negates any user bias in the source locations. The sensitivity maps are created by simulating numerous uniformly distributed sources simultaneously and locating these sources using TRI. The found source locations are compared to the initial source locations to estimate the achieved accuracy. The resulting sensitivity maps show that the station geometry introduces complex patterns in the spatial variation of accuracy. Furthermore, the influence of the station geometry on the source–location accuracy is larger than the influence of the velocity model. Finally, a microearthquake recorded at the geothermal site of Los Humeros is located to demonstrate the usability of the derived sensitivity maps. This study stresses the importance of optimizing station networks to enhance the accuracy when locating seismic events using TRI.

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