A PDE-Based Method of Equivalent Source Upward Extension and Downward Extension of Magnetic Measurement Data

Abstract

The present invention provides a PDE-based equivalent source up extension and down extension method for magnetic measurement data, including: S1, obtaining magnetic field data d 0 , and establish a terrain relief surface according to the terrain height information of the area where the magnetic field data is located; S2, determine the spatial range of grid division, and perform non-uniform multi-layer grid division; S3, according to the magnetic inclination angle, magnetic declination angle and Magnetic induction, for magnetic field data d 0 Carry out the PDE three-dimensional inversion calculation with depth regularization factor, positive constraint term and regularization term, and obtain the multi-layer equivalent source model of magnetic anomalies; S4. Use the multi-layer equivalent source model to carry out magnetic field forward modeling based on PDE Calculate and obtain the magnetic field data after the upward continuation and / or the downward continuation produced by the magnetic anomaly. The beneficial effect of the present invention is that it can carry out self-adaptive and high-precision upward or downward continuation on underground magnetic anomaly data in complex environments.

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...

AI Technical Summary

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

Images