The Applied Research Into The Kernel Function Fit Method Based On Linear Filtering For Data Processing In Vertical Electric Sounding

Electrir-resistivity method had hundred years history. Its theory, technology, equipment, forward and inverse methods are mature. From simple electrical profiling and electrical sounding to high density resistivity method, techniques of electrical prospectings became more and more advanced,but their most important parts were original simple electrical profiling still.Most datas of electrical prospectings were gathered on the ground besides electrical logging. So it was difficult to meet the actual surveying requirements when geologic setting was complicated. It therefore is essential to have a post processing of field datas that is suitable to that condition, to make up for many-sided deficiencies of field surveying to a certain extent. Kernel function fit method based on linear filtering was developed, following the popularization of computer application, as a data processing technology. Now, it is widely applied in field of electrical sounding data processing.The author studies the practical methods about directly processing and interpretation of apparent resistivity data collected in field, that proposed by Koefoed in 1968, and the practical methods about extracting the resistivity kernel function from actual apparent resistivity curve based on linear filter method, that proposed by D.P.Ghosh. According to the properties of conversion function curve of symmetrical four-pole sounding, with the same way of BOSTICK in magnetotelluric sounding, the resistivity kernel function was derived for the inversion methods.This paper expounds the basic theory and the formula of linear filter and the fitting method of kernel function, and how to use them for electrical sounding data processing. The electrical model is established with different thickness,different depth,different resistivity,and to verify the application effect of fitting method of kernel function in pure conditions. Finally, after testing six models of the resistivity curve of the conversion function, then the inversion method of fitting the kernel function is applied to solve the problems of two actual works.In this paper, through the study of kernel function fit method based on linear filtering,it showed this method has good application effect in the field of resistivity sounding technique data processing,and provides more choice for solving the complex geological problems.