描述了一种在层状介质中,从一束源激发产生反射记录上获取速度、密度的反演方法。通过把测点的所有波分解为两类,一类是第 n 层反射所得的波,另一类是前 n-1层反射所得的波。在假设已知前 n 层介质的情况下,把反演第 n+1层的问题化为一...描述了一种在层状介质中,从一束源激发产生反射记录上获取速度、密度的反演方法。通过把测点的所有波分解为两类,一类是第 n 层反射所得的波,另一类是前 n-1层反射所得的波。在假设已知前 n 层介质的情况下,把反演第 n+1层的问题化为一个线性回归。一些数值例子表明该反演方法较好地恢复了产生标准资料的那些参数。因为是线性回归方法,所以计算量小且精度较高。本文所给搜索波方法也是一个适合于计算机实现的较好的正演方法。展开更多
We present a method to unify the calculation of Green＇s functions for an electromagnetic（EM） transmitting source embedded in a homogeneous stratified medium.A virtual interface parallel to layer interfaces is intro...We present a method to unify the calculation of Green＇s functions for an electromagnetic（EM） transmitting source embedded in a homogeneous stratified medium.A virtual interface parallel to layer interfaces is introduced through the source location.The potentials for Green＇s function are derived by decomposing the partial wave solutions to Helmholtz＇s equations into upward and downward within boundaries.The amplitudes of the potentials in each stratum are obtained recursively from the initial amplitudes at the source level.The initial amplitudes are derived by coupling with the transmitting sources and following the discontinuity of the tangential electric and magnetic fields at the source interface.Only the initial terms are related to the transmitting sources and thus need to be modified for different transmitters,whereas the kernel connected with the stratified media stays unchanged.Hence,the present method can be easily applied to EM transmitting sources with little modification.The application of the proposed method to the marine controlled-source electromagnetic method（MCSEM） demonstrates its simplicity and flexibility.展开更多
文摘描述了一种在层状介质中,从一束源激发产生反射记录上获取速度、密度的反演方法。通过把测点的所有波分解为两类,一类是第 n 层反射所得的波,另一类是前 n-1层反射所得的波。在假设已知前 n 层介质的情况下,把反演第 n+1层的问题化为一个线性回归。一些数值例子表明该反演方法较好地恢复了产生标准资料的那些参数。因为是线性回归方法,所以计算量小且精度较高。本文所给搜索波方法也是一个适合于计算机实现的较好的正演方法。
基金supported by CNSF(Granted No.40874050)Chinese High Technology Project(Granted No.2011YQ05006010)
文摘We present a method to unify the calculation of Green＇s functions for an electromagnetic（EM） transmitting source embedded in a homogeneous stratified medium.A virtual interface parallel to layer interfaces is introduced through the source location.The potentials for Green＇s function are derived by decomposing the partial wave solutions to Helmholtz＇s equations into upward and downward within boundaries.The amplitudes of the potentials in each stratum are obtained recursively from the initial amplitudes at the source level.The initial amplitudes are derived by coupling with the transmitting sources and following the discontinuity of the tangential electric and magnetic fields at the source interface.Only the initial terms are related to the transmitting sources and thus need to be modified for different transmitters,whereas the kernel connected with the stratified media stays unchanged.Hence,the present method can be easily applied to EM transmitting sources with little modification.The application of the proposed method to the marine controlled-source electromagnetic method（MCSEM） demonstrates its simplicity and flexibility.
