The algorithm of high order finite difference pre-stack reverse time migration and GPU implementation

Pre-stack reverse time migration (RTM) is a very useful tool for seismic imaging. But it has not been widely used because of the highly intensive computation cost, imaging noise and massy memory demand. In this paper, we illustrate the implementation process of RTM and analyze the stability condition and dispersion relation of finite difference (FD) method. For the problem of intensive computation cost, we use the Graphic Processing Unit (GPU) architecture to realize RTM and get an order of magnitude higher speedup ratio compared to the traditional CPU architecture. Compared to the one way wave equation migration methods, RTM does not have the imaging dip limit and the imaging effect is significantly improved. The test on vertical fault and BP models proves this conclusion. The problems of imaging noise removing and massy memory demand will be discussed in other papers.