Getting pre-stack time migration travel times from the single square root operator
Liu Guo-Feng1,2, Liu Hong1, Li Bo1,2, and Meng Xiao-Hong2
1. Key Laboratory of Petroleum Geophysics, Institute of Geology and Geophysics, CAS, Beijing 100029, China.
2. State Key Laboratory of Geological Processes and Mineral Resources Geo-detection Laboratory of the Ministry of Education, Beijing 100083, China.
Abstract：
Improving the focusing capability of pre-stack time migration allows the imaged section to reflect structural characteristics, depth, and interface shape and it is a key step for the preparation of the initial depth migration velocity model. The traditional symmetrical travel time equation is derived based on the assumption of a layered model. It is difficult to achieve the desired effect of focusing in media with strong lateral variation. The non-symmetrical travel time equation based on Lie algebra and a pseudo-differential operator contains a lateral velocity derivative which can improve the focusing capability even in strongly lateral variable media and also the computation precision of the weight coefficients for relative amplitude preservation. Compared with the symmetrical methods, the non-symmetrical method is more effective. In this paper, we describe several key steps of non-symmetric pre-stack travel time calculation and present some test results using synthetic and real data.
LIU Guo-Feng,LIU Hong,LI Bo et al. Getting pre-stack time migration travel times from the single square root operator[J]. APPLIED GEOPHYSICS, 2009, 6(2): 129-137.
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2009, Vol. 6 
