Abstract：My method involves the following essential points:·Reflection coefficients are derived from reduced Zoeppritz's equation,then convolved with seismic wavelet.·The least square problem of the convolution result and real seismic data can be considered as the solution of a huge rarefactional matrix equation,which can be solved by singular value decomposition.·The influence of wavelet error must not be neglected in the convolution.·Acoustic log velocity or laboratorial velocity should be used in calibration in solving the equation and matrix.·The velocities of P and S-waves in medium can be downward estimated in one pass.
