| Summary: | 碩士 === 國立臺灣大學 === 電子工程學研究所 === 103 === An earthquake early warning system has to rapidly detect the onset of an earthquake to reduce the damages done by the quake. However, the accuracy of earthquake location is often limited by the simplicity of the velocity model.
Numerous researches have been done to shorten the computing times of hypocenter searching processes, raise prediction accuracy, and better simulate seismic wave propagation. However, few have utilized historical event data in practice.
This thesis proposed an earthquake locator that calibrates station trigger times based on their historical behavior. The systematic uncertainties in seismic wave propagation are modeled in the form of trigger offsets. P wave arrival times are adjusted according to the offset obtained from historical records. A station selection method was introduced to further increase calibration accuracy. The proposed calibration scheme would develop with its experience to earthquake events, increasing the stability of its calibration accuracy.
Experiment results indicate a constant improvement in predication accuracy when the station selection technique is solely applied. The effect of offset cancelling is not stable, it has proven to be effective in certain cases, but deteriorates prediction accuracy in others.
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