Three-dimensional high-efficiency and high-precision numerical simulation of gravity and magnetic potential fields of complex body
ZHOU Yinming1,2,3, DAI Shikun1,2, LI Kun1,2, LING Jiaxuan1,2, HU Xiao-ying3, XIONG Bin4
1. School of Geosciences and Info-physciences, Central South University, Changsha, Hunan 410083, China; 2. Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring, Ministry of Education, Changsha, Hunan 410083, China; 3. GME & Geochemical Surveys of BGP, CNPC, Zhuozhou, Hebei 072751, China; 4. College of Earth Sciences, Guilin University of Technology, Guilin, Guangxi 541006, China
Abstract：The forward modeling of gravity and magnetic potential fields is the basis of inversion and interpretation.For applicable forward algorithms,it is difficult to consider both calculation accuracy and calculation efficiency in complex conditions.A three-dimensional numerical simulation method for gravity and magnetic potential fields is proposed.It transforms the three-dimensional integration of gravity and magnetic potential fields to one-dimensional integration with independent wave number through two-dimensional Fourier transform in the horizontal direction.The one-dimensional integral can be discretized vertically into the sum of the integrals of multiple elements,and shape function interpolation is conducted within the element.Both the calculation accuracy and efficiency are high.This method makes full use of the high accuracy of the shape function integral and the high efficiency of the Fourier transform. Finally,a prism model is designed,and the analytical solution to the model is compared with the numerical solution to the method,indicating that the theory of the method is correct and the accuracy is high.A complex model with continuous vertical variation is designed,and the accuracy of traditional prism uniform subdivision is compared with the quadratic interpolation of shape function method,proving that the method has a high applicability to the complex model.
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