广义WKB法在波场模拟中的应用研究

针对地震勘探中的波场模拟和反演困难等问题，本文从二维波动方程出发，采用Fourier变换得到了赫姆霍兹方程，并创造性地提出了一种全新的近似解法－广义WKB法；该法可以更加近似赫姆霍兹方程，且它的解中包含WKB的近似值.数值模拟显示了WKB法与广义WKB求解的异同.结果表明：广义WKB法是WKB法的一种推广，在求解非线性波数问题时具有更好的优势.

Study of gGeneralized WKB applied to wave field's simulation

Based on 2-deminsion wave equation using Fourier transform this paper gives Helmholtz equation and the generalized WKB,which is a new approximation method for solving difficulties in wave field analogy and difficulties of inversion in seismic exploration.The method can make it more approximation to Helmholtz equation and it's answers include WKB approximation.The difference between WKB and generalized WKB is illustrated in numerical experiment by figures.From the results,we may draw that the generalized WKB is the development of WKB method with greater dominance in solving the problems with nonlinear wave number.