Goos-Hnchen效应对自由表面全反射SV波校正时差的影响

The influence on normal moveout of total reflected SV-wave by Goos-Hnchen effect at a free surface of stratum

利用SV地震波(偏振化方向在入射面内的横波)在自由表面反射系数的附加相角导出了SV波Goos-Hnchen效应所引起的横向偏移和横向偏移渡越时间,给出了Goos-Hnchen效应正常时差动校正量,讨论了Goos-Hnchen效应对反射SV波正常时差的影响,绘出了横向偏移、Goos-Hnchen效应正常时差及Goos-Hnchen效应正常时差校正量曲线.曲线表明:反射地震波存在负横向偏移效应,在大多数入射角度范围,横向偏移(横向偏移渡越时间)与波长(周期)为同一个数量级.对掠入射波或入射角在临界角附近的入射波,Goos-Hnchen效应对正常时差有较大的测量误差,对反射P、SV波的传播走时产生了不可忽略的影响,因此在实际的地震资料处理中应进行横向偏移效应误差校正.

Using the phase shift of reflection coefficient of SV seismic wave at the free surface of stratum, we derived the lateral shift and group time delay of total reflected SV seismic wave, gave the formulae of normal moveout of Goos-Haenchen effect, discussed the influence of Goos- Haenchen effect on normal moveout of SV-wave, and drew the curves of lateral shift , normal moveout of Goos-Haenchen effect and error of normal moveout caused by Goos-Haenchen effect with respect to the angle of incidence. The results show that reflected wave has negative Goos- Haenchen shift; for glancing wave or near-critical incidence angle, a large error can be caused by Goos-Haenchen effect. In other angle of incidence the lateral shift is the same order of magnitude as the wavelength. So Goos-Haenchen effect can bring about large influence on the travel time of P-wave and SV-wave. The error correction of Goos-Haenchen effect should be made before seismic data processing.