Title: A multi-channel approach for automatic microseismic event localization using RANSAC-based arrival time event clustering(RATEC),
Abstract: In the presence of background noise and interference, arrival times picked
from a surface microseismic data set usually include a number of false picks
which lead to uncertainty in location estimation. To eliminate false picks and
improve the accuracy of location estimates, we develop a classification
algorithm (RATEC) that clusters picked arrival times into event groups based on
random sampling and fitting moveout curves that approximate hyperbolas. Arrival
times far from the fitted hyperbolas are classified as false picks and removed
from the data set prior to location estimation. Simulations of synthetic data
for a 1-D linear array show that RATEC is robust under different noise
conditions and generally applicable to various types of media. By generalizing
the underlying moveout model, RATEC is extended to the case of a 2-D surface
monitoring array. The effectiveness of event location for the 2-D case is
demonstrated using a data set collected by a 5200-element dense 2-D array
deployed for microearthquake monitoring.