PDE-based gravitational field data equivalent source continuation and data type conversion method

Abstract

The invention provides a PDE-based gravitational field data equivalent source continuation and data type conversion method. The method comprises the steps of: S1, inputting gravitational data d0, andestablishing a topographic fluctuating curved surface according to topographic height information of an area where the gravitational field data is located; S2, determining a spatial range of mesh generation according to the elevation information of the fluctuating observation curved surface of aerial survey and a set inversion maximum depth, and performing continuous structured non-uniform mesh generation on the spatial range according to the topographic fluctuating curved surface to further determine an equivalent source inversion mesh space; S3, according to a gravity background field U0, performing PDE three-dimensional inversion calculation with a depth regularization factor, a positive value constraint term and a regularization term on the gravity field data d0 based on the equivalentsource inversion mesh space to obtain a multi-layer equivalent source model of a gravity anomalous body; and S4, giving different observation parameters, and carrying out nonlinear PDE gravity fieldthree-dimensional forward modeling calculation by utilizing the multi-layer equivalent source model to obtain one or more of gravity anomaly vertical data, gravity anomaly field data Us' and gravity gradient tensor data generated after the continuation of the gravity anomaly body at different observation positions. The method can achieve the adaptive and high-precision continuation and data type conversion calculation of underground gravity abnormal data in a complex environment.

Description

technical field [0001] The invention relates to the technical field of geophysical surveying, in particular to a method for equivalent source extension and data type conversion of gravity field data based on PDE. Background technique [0002] In gravity detection, people usually detect the vertical first derivative of the gravity field, but in actual data interpretation, it is often necessary to convert these data into required parameters and types, such as different observation heights (continuation), The conversion of gradient tensor data, etc., the main challenge of gravity field data type conversion lies in the undulating measurement surface of aerial survey and the irregular measurement position of data (non-grid measurement), traditional data type conversion and continuation calculation are difficult to process these data , while using traditional single-layer, double-layer, and three-layer equivalent source data conversion methods, the accuracy of the processing resul...

AI Technical Summary

Problems solved by technology

[0007] The application of these technologies enables people to perform polarization and data type conversion operations of ground gravity data through equivalent source technology, but there are the following problems: 1) The equivalent source grid can only be constructed with a maximum of three layers, and the grid division discontinuous, the existing technology has limited layers of equivalent sources and unreasonable grid division of underground space, which affects the accuracy and speed of gravity field continuation and data type conversion; 2) each equivalent source needs to be separately estimating the depth position of the layer, and then placing it separately; 3) Using the linear forward modeling method and the linear model inversion method to calculate the equivalent source, the anti-interference ability and calculation accuracy are poor

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