A generalized high order screen extrapolator of double square root ( dsr ) equation is derived from the non - stationary phase shift formula of wavefield continuation , thus a new prestack depth migration method in the cmp - offset domain is proposed 在波场延拓方面，从非稳态相移公式出发，推导出广义高阶屏双平方根波场延拓公式，从而得出了一种新的共中心点-炮检距域叠前深度偏移方法。
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The migration results of the synthetic and ocean field datasets show that this method is correct and effective . several prestack depth migration methods are proposed and unified to the synthetic source record migration method . these methods include plane wave migration with fourier finite difference ( ffd ) extrapolator , maximum energy plane wave migration and prestack migration with phase encoding of areal shot records 通过对本文提出的平面波傅立叶有限差分叠前深度偏移方法、最大能量面炮记录叠前深度偏移方法和相位编码面炮记录叠前深度偏移方法的研究，试算和对比，提出了合成震源三原则，根据这些原则，提出了合成震源概念和合成震源记录叠前深度偏移方法。
