利用能量比法拾取地震初至的一种改进方法

An improved method for first arrival pickup using energy ratio

中国地质大学地球物理与信息技术学院,北京 100083

Faculty of Geophysics and Technology Information, China University of Geosciences, Beijing 100083, China

介绍了能量比法拾取地震道初至的一种改进方法,即利用时窗滚动来计算能量比值,并从比值特征中判断初至。在以前的计算中是把要计算的地震道划分成许多个时窗,然后逐个求能量比值。由于各道初至的到达有先有后,如果静态地划分时窗,有可能初至到达前后时窗的能量比值并不是最大的,也就是说这时的拾取结果是错误的。但是通过时窗滚动可以多次计算初至前后时窗内的能量比值,经比较得出最佳比值。改进的方法能快速准确地拾取地震道的初至,并且可以提高拾取的精度和稳定性。

This paper presents an improved method for first arrival pickup using er.ergy ratio. This method calculates the energy ratios in rolling windows, and then estimates the first arrival from the ratios. Previously energy ratios were calculated in time windows predefined on seismic traces. First arrivals varied with traces, thus predefined windows sometimes leaded to wrong pickups because the calculated energy ratios may not reach to the maximum in the given windows. Optimum energy ratio can be determined by comparing different energy ratios calculated in th rolling windows. The improved method is stable and it can pick up first arrivals on seismic traces more quickly and accurately.