The research and application in inversion method of rayleigh surface wave dispersion curves

摘要

Surface wave exploration has an advantage over all other wave exploration in complex shallow geological structure, especially in desert, so it can replace refracting wave method and micro-seismic logging method in oil seismic exploration. The self-adaptively iterative damping least square method by weighting matrix is proposed in this paper. The method increase weighting value for gradient when get gradient, and increase weighing value for independent variable of every component, and standardize to conduct gradient and step size when hunt the least of object function, then bring down abnormal state degree. The new efficient algorithm can overcome such serious shortcoming existent in the classic least square Method as the strict dependence on initial model. The inversion results of the new theoretical model and field dispersion data indicate that this inversion is characterized by good stability, high accuracy and strong resolution and has good application result in shallow geological structure.