| Multiple-reflection is a widespread problem in marine seismic prospecting in our country, it interferes the fidelity of seismic imaging, degrades the rate of S-N, misleads the interpretation of the seismic section. Therefore, multiple attenuation is one of the critical steps in marine data processing. The predict-subtraction method, which predicting the multiples and subtracting it from the seismic data directly, could attenuate multiples without distorting the primary effectively. So it is an important direction of the multiple attenuation.According to the two steps of prediction and subtraction, multiple prediction method based on moveout-equation is engaged for predicting multiple-model traces and matching subtraction method is adopted for subtracting multiple form original data in my study. The independence of the two processes is ensured when bringing the predict-subtraction method to effect. They can attenuate multiple when combining with other prediction or subtraction methods respectively.The multi-order surface-related multiple prediction based on moveout-equation is realized in this paper; We summarize the four methods about single channel matching subtraction, normal multi-channel matching subtraction, pseudo-multi-channel matching subtraction and expanded multi-channel matching subtraction in detail. The improved methods are presented after analyzing the advantage and disadvantage of the four methods. The algorithms of improved multi-channel matching subtraction and improved expanded multi-channel matching subtraction are given. The tests of physical model data and real data show that the improved algorithms are more adaptable and stable, and the calculation capacity is reduced. The main matching parameters on filter length, calculation window and adjacent trace numbers are analyzed and tested. Furthermore, we apply iterative algorithm to the matching subtraction, it indirectly testifies the effectiveness of improved expanded multichannel matching subtraction method.
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