A multi-layer equivalent source extension and data conversion method for gravity data

Abstract

The invention provides a gravity data equivalent source continuation and data conversion method, comprising: inputting the gravity field data d on the undulating observation surface 0 , according to the terrain information of the area where the observation surface is located, establish a terrain undulation surface; according to the undulation observation surface and the set inversion maximum depth, determine the grid division range, and perform grid division on the range to determine the model space; According to the gravity background field, based on the model space to the gravity field data d 0 Carry out the three-dimensional inversion calculation of the integral equation with constraints and regularization terms to obtain the equivalent source model of the gravity anomaly body; determine the sensitivity matrix G′ according to the position of the continuation surface, and then use the equivalent source model to carry out gravity calculation based on the integral equation The field forward calculation is used to obtain the extended gravitational field data U generated by the abnormal body s ; to U s Perform gradient tensor transformation. The invention can self-adapt to the gravity anomalous body and quickly, efficiently and accurately generate the required extended and data-converted data.

Description

technical field [0001] The invention relates to the technical field of gravity exploration, in particular to a multi-layer equivalent source extension and data conversion method for gravity data. 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 results is low, which ...

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Problems solved by technology

[0004] The application of these technologies enables people to use the equivalent source technology to perform polarization and data type conversion calculations for ground gravity data, but there are the following problems: 1) The number of equivalent source layers constructed by the above method is usually less than or equal to three layers, and the network The grid division is discontinuous; 2) The depth position of each equivalent source needs to be estimated separately, and then placed separately; 3) The traditional continuation method has limitations on the continuation distance of the data (generally less than 6 times the data point distance) , the calculation accuracy of continuation larger than the limit distance is poor

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