Abstract：Improving the fitting precision of zero-offset seismic trace is one of key links of amplitude-preserved seismic data processing.In comparison with conventional seismic stack technique,the second-order polynomial fitting technique can improve the fitting precision of zero-offset seismic trace,but the AVO character of reflected signal is variation for the strata in different times,which means that only using second-order polynomial to implement the zero-offset seismic trace fitting is not enough.Using orthogonal polynomial to describe the AVO character of reflected signal for the strata in different times on CMP gathers and self-adaptive determining the orders needed for fitting the signals of zero-offset traces in different times based on the energy of useful waves evaluated by SVD,the paper realized high-precision zero-offset seismic trace fitting.The synthetic records and practical data processing showed that the method is able to effectively reduce the fitting errors of zero-offset seismic trace and improve the fitting precision.
