Implement of optimal separable approximation in seismic migration
地震偏移的最优可分近似算法实现

An optimal separable approximation(OSA) is applied to the characteristic function of one-way wave operator in the seismic migration algorithm.The characteristic function is expressed as products of functions in space variable(g) and functions in wave number variable(k).Based on the optimal separable approximation,the mixed domain algorithm with Fourier and inverse Fourier transformation is used to approximate the one-way wave operator.To overcome numerical instability from approximating characteristics function near the singular point,an equivalent sticking skill is adopted to improve algorithmic stability.Moreover,separate frequency computation and linear interpolation for space variables are used to improve precision and save time.The impulse response of one-way wave operator on simples and the complex lateral variable velocity model shows that the optimal separable approximation can apply to lateral velocity variation in the case of small steps.Results on the Marmousi model test show the new method can also be used to image complex structure.