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由紧密排列的阻抗界面引起的调谐作用影响着地震振幅。在零炮检距处,当层厚减小时,合成反射信号的形状接近原始脉冲的时间导数。对于厚度小于调谐厚度一半的层来说,反射振幅被佃当于两倍于薄层时间厚度的因子修正。与炮检距有关的调谐作用可用一次反射之间的时差来近似表示。在速度差异很大时,局部转换波也影响着总的反射地震响应。在多数情况下,层间多次波的影响可被忽略。在常规AVO分析前应对与炮检距有关的调谐效应进行校正。
The tuning effect caused by the close-packed impedance interface affects the seismic amplitude. At zero offset, as the layer thickness decreases, the shape of the composite reflected signal approximates the time derivative of the original pulse. For layers less than one-half the thickness of the tuning, the reflection amplitude is corrected by a factor equal to twice the thickness of the layer. The tuning effect associated with the offset can be approximated by the difference in time between reflections. When the velocity varies a lot, the locally converted wave also affects the total reflected seismic response. In most cases, the effects of inter-layer multiples can be neglected. The tuning effects associated with the offset should be corrected before routine AVO analysis.