CAJ | 학술논문

初至波地震层析成像需要给定初始速度模型，给定的初始速度模型很大程度上影响层析反演的质量、反演是否收敛和收敛速度的快慢。使用层析成像反演近地表速度场时，这里提出了一种利用大炮初至时间自动生成初始速度模型的方法。假定大炮初至是由直达波和折射波构成的，然后用折射波法直接求取初始速度模型，该方法生成的初始速度模型可直接由程序自动实现，无需人为干扰。将该方法应用在理论模型和实际资料中，由此产生的初始速度模型采用层析成像技术进行迭代反演，结果表明，该方法建立的初始模型加快了反演收敛速度，反演结果和真实速度模型基本一致。
초지파지진층석성상수요급정초시속도모형，급정적초시속도모형흔대정도상영향층석반연적질량、반연시부수렴화수렴속도적쾌만。사용층석성상반연근지표속도장시，저리제출료일충이용대포초지시간자동생성초시속도모형적방법。가정대포초지시유직체파화절사파구성적，연후용절사파법직접구취초시속도모형，해방법생성적초시속도모형가직접유정서자동실현，무수인위간우。장해방법응용재이론모형화실제자료중，유차산생적초시속도모형채용층석성상기술진행질대반연，결과표명，해방법건립적초시모형가쾌료반연수렴속도，반연결과화진실속도모형기본일치。
The initial velocity model is primary given in first-arrival seismic tomography,the quality of tomography inver-sion,convergence and convergence speed are effected mostly by the initial velocity model.An automatically building initial ve-locity model using first-arrivals has been proposed with near-surface velocity fields tomographic inversion in the paper.As-suming that the first-arrivals are consist of the direct waves and refraction waves,then the initial velocity model is directly cal-culated by refraction method,which can be realized automatically by program without factitious interfere.The method is ap-plied to the theory model and actual data,then the iterative tomography technique is applied to obtain actual velocity model based on the initial velocity model.The results show that the method is effective with quickly convergence,and the inversion results are consist with real velocity model.