The Acoustic Encoded Full Waveform Inversion Method Research In Areas With A Rugged Surface

With the development of FWI,FWI has been involved in research of seismic wave field simulation,objective functional,gradient estimation,parallelism strategy etc.Recent years,the full waveform inversion with aliasing data,gradually become a hot research topic.At present,some aspects restrict practical process of FWI,such as: computational stability,convergence of inversion iterative,iteration efficiency.To solve these problems,many researchers had conducted a lot of research,encoding was a popular strategy.On the basis of the programming,through trial for simple sub-sag model and complex Marmousi model,we get several understanding: 1?aliasing data with no coding exist crosstalk noise,the residual increased after 15 inverse iteration times,the inversion is not convergence;2?optimum step length coding FWI is better solve the problem of the convergence and stability of inversion,the inversion results error function curve is smoothing and has decreasing residual,this method verifies the validity and applicability of the new method.Full waveform inversion(Tarantola,1984),as a kind of important velocity modeling method,especially in geologically complex areas,has been the hot topics in the study of geophysical workers.Forward modeling is the basis of the full waveform inversion,and have a lot of calculation.The key of irregular surface waveform inversion algorithm is forward algorithm considering the influence of the surface of the earth.For irregular surface,we put forward a method of coordinate transformation,transforming irregular surface mapping into horizontal surface,then we inverse velocity model based on phase encoded.On the basis of the programming,model trial of zhong yuan model shows that this method can accurately simulate the seismic wave field and imaging correctly,greatly improves the efficiency of the inversion,verifies the validity and better adaptability.