The Research Of Downward Continuation Of Regularization Methods For Magnetometric Field Based On The Depth Change

Volcanic reservoir, which was found in many basins and blocks of the world, showed the huge exploration potential and caused widespread condern. Because of the shielding effect, the response characteristics of seismic profiles were complex, and the imaging was poor, the method of seismic is difficult to distinguish the volcanic. With a significant magnetic susceptibility of igneous rocks, it has many advantages when using magnetic method.The continuation of potential field is an important method. Upward continuation, which can be derived strictly in accordance with math method, can get a good result when used for dealing with actual data; downward continuation, which direction is from observation plane to field source, is a typicall ill-posed problem. Upward continuation would be failed because of the high frequency oscillations effects of the process. In order to get more detailed characteristics of source field, it must be closeer to it. So it is necessary to search a more reasonable method to suppress high frequency oscillation and to achieve stability and accuracy during downward continuation.On the basis of previous studies, this paper put forward a magnetic regularization downward continuation method based on the depth changes. This paper contains the regularized solution of ill-posed problem, the solutions of filter parametersαandβ, and focusing on the obtain of cut-off frequency which was based on the depth changes. Finally, during model test and actual data processing of Chepaizi, it was found that the method is accurate, stable and practical.