PDE-based magnetic measurement data equivalent source upper continuation and lower continuation method

Abstract

The invention provides a PDE-based magnetic measurement data equivalent source upper continuation and lower continuation method, which comprises the steps of S1, obtaining magnetic field data d0, andestablishing a topographic relief curved surface according to topographic height information of an area where the magnetic field data is located; s2, determining a spatial range of mesh generation, and performing non-uniform multilayer mesh generation; s3, according to the magnetic inclination angle, the magnetic declination angle and the magnetic induction intensity of the geomagnetic field, carrying out PDE three-dimensional inversion calculation with a depth regularization factor, a positive value constraint term and a regularization term on the magnetic field data d0 to obtain a multi-layer equivalent source model of the magnetic anomalous body; and S4, performing PDE-based magnetic field forward modeling calculation by using the multilayer equivalent source model to obtain upper continuation and / or lower continuation magnetic field data generated by the magnetic anomalous body. The invention has the beneficial effect that self-adaptive and high-precision upper continuation or lower continuation can be carried out on underground magnetic anomaly data in a complex environment.

Description

technical field [0001] The invention relates to the technical field of geophysical surveying, in particular to a PDE-based equivalent source up-extension and down-extension method for magnetic survey data. Background technique [0002] When geophysical magnetic methods (such as aeromagnetic survey and ground magnetic survey) are used for detection, the measurements are distributed on the surface of the undulating observation surface. Since the distance between the measurement position and the magnetic anomalous body is different, the main anomaly information reflected by the magnetic survey data also varies. difference. In practical applications, it is necessary to convert the measurement position of the data to meet the interpretation requirements of magnetic data processing. That is to extend the data on the observation surface to a higher observation surface to eliminate the influence of anomalous bodies closer to the observation surface on the magnetic field, thereby hi...

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Problems solved by technology

[0005] However, these techniques have the following problems: 1) The number of equivalent source layers constructed by the above method is less than or equal to three layers, and the grid division is discontinuous; 2) The depth position of each equivalent layer needs to be estimated separately, and then 3) The traditional continuation method has a limit on the continuation distance of data (generally less than 6 times the data point distance), and the calculation accuracy of continuation greater than the limit distance is poor; 4) The above method adopts linear forward modeling method and linear model The inversion method calculates the equivalent source, and the anti-interference ability and calculation accuracy are poor

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