基于STA/LTA和分形维算法的微震事件初至自动拾取方法

精确拾取微地震事件初至是微震定位的关键技术之一。根据STA/LTA和分形维数两种微地震初至拾取方法的原理,采用理论模型数据对两种初至拾取方法进行了测试,并选取不同信噪比的实际数据从初至拾取精度、算法效率两个方面进行了对比。结果表明,对于高信噪比微震事件,两种方法都能获得精度较高的初至,但对于低信噪比微震事件,分形维数与STA/LTA比较其拾取精度相对要高。鉴此,运用STA/LTA和分形维两种算法相结合的微震事件初至拾取方法,对实际数据进行了处理,实现了微震事件初至较为准确的自动拾取。

Automatic Picking of Microseismic Event Primary Arrival Based on STA/LTA and Fractal Dimension Algorithm

The microseismic primary arrival picking accurately is one of key technologies in microseismic positioning. Based on the two picking method principles of the STA/LTA and fractal dimension, have carried out tests using theoretical model data, and selected practical data of different S/N ratios contrasted from two aspects of primary arrival picking accuracy and algorithmic efficiency. The result has shown that to the high S/N ratio microseismic events, the two methods can both obtain rather high accurate primary arrivals, but to the low S/N ratio microseismic events, the accuracy from fractal dimension is relatively higher than from STA/LTA. On this account, using combined algorithms of the two methods processed practical data and realized rather accurate automatic picking of microseismic event primary arrivals.