1. School of Geosciences and Info-Physics, Central South University, Changsha, Hunan 410083, China; 2. Key Laboratory of Metallogenic Prediction of Nonferrous Metals, the Ministry of Education, Central South University, Changsha, Hunan 410083, China
Abstract:According to the reverse-time migration imaging principle, we use forward and reverse wave field extrapolations with high order staggered-grid finite difference method to solve wave equations. Forward and reverse wave field extrapolations are carries out on seismic data recorded with different receiving directions, different spread lengths, and different receiver intervals. Then the difference between two fields is obtained, and artifacts on seismic data with different receiving directions are analyzed by reverse time migration. We obtain the following observations: A. a new wave field will be generated in backward wave field extrapolation if the seismic data is not complete, and then artifacts will be present on pre-stack reverse time migration, and these artifacts can be suppressed by staking; B. effects of spread length on reverse time migration is larger than receiver interval.