Converted-wave pre-stack time migration in volcanic area
火山岩地震屏蔽层的转换波叠前时间偏移成像

How to get exact common converted points is a key problem in processing reflection seismic converted wave data.Using pre-stack time migration technology(PSTM),we can exactly image the converted waves on the true reflection points and avoid sorting common converted point(CCP) gathers.In this paper,we research the imaging problems beneath volcanic area.We sort common asymptotic conversion point(CACP) gathers and perform velocity analysis to establish the initial velocity which will be used in PSTM.By scanning migration velocity and Vp/Vs,we get the optimum migration velocity and Vp/Vs.Using real data from a seismic exploration,we achieved the migration sections of converted wave beneath volcanic area,and it is proved that the method is effective for computing common asymptotic conversion point and pre-stack time migration.