The Research On Stable Downward Continuation Based On Inverse Algorithm

Field continuation is an important part of geophysical data processing methods,after half a century of development,many ways technology has been more mature.In the geological data and field research of solid mineral resources exploration and other areas have a wide range of applications.With the social development and progress of potential field continuation of accuracy,stability and computational efficiency are put forward higher requirements.Upward continuation is stable,but downward continuation is unstable,in view of this,potential field downward continuation of technology in recent decades attention of many scholars,and achieved rapid development.The downward continuation is different from the upward continuation,which is a typical ill-posed problem.On the basis of in-depth study of the principle of continuation potential field,combined with the generalized inverse theory,the potential field downward continuation regarded as the reverse process of upward continuation,to construct a linear equation by extension ideas reference linear inversion equation,using the matrix form of the Fourier transform,conjugate gradient method for solving equations.However,the reference is the inversion equations idea,it has a defect in practice equation calculation stability,and therefore,the introduction of improvements in the operator equation to be improved to overcome the downward continuation instability problems.Configured to select functions to select an improved damping factor,herein by reference regularization coefficient selected manner,so that further improves the effect of downward continuation process,improve stability.Based on the principle of generalized inverse theory,it will be seen as the reverse process of downward continuation of the upward continuation,on the basis of downward continuation inverse algorithm,the core operators to improve.Theoretical model tests indicate improved damping factor of the inverse downward continuation algorithm has higher efficiency,effectively shortening the transition frequency data band,high frequency information compressed more obvious,can be more precise and stable continuation result.The paper summarized research mainly in the following areas:The basic principle of the spatial domain and frequency domain above bit extension field analysis are set forth,it discusses the basic process of downward continuation process.Analyze the principle of the common method of iterative downward continuation,and discuss the related problems by referring to the solution of regularization problem for the downward extension instability problem.The downward continuation is regarded as the inverse process of upward continuation.On the basis of the downward continuation algorithm,the original core operator is improved to achieve the purpose of stable extension,and the selection function is constructed to optimize the damping factor.choose.