Fast 3D forward modeling of the magnetic field and gradient tensor on an undulated surface
Li Kun1,2,3, Chen Long-Wei4, Chen Qing-Rui1,2,3, Dai Shi-Kun1,2,3, Zhang Qian-Jiang1,2 ,3,4, Zhao Dong-Dong1,2,3, and Ling Jia-Xuan1,2,3
1. Hunan Key Laboratory of Nonferrous Resources and Geological Hazards Exploration, Changsha 410083, China.
2. Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring of Ministry of Education, Central South University, Changsha 410083, China.
3. School of Geosciences and Info-Physics of Central South University, Changsha 410083, China.
4. School of College of Earth Sciences of Guilin University of Technology, Guilin 541004, China.
Abstract：
Magnetic field gradient tensor technique provides abundant data for delicate inversion of subsurface magnetic susceptibility distribution. Large scale magnetic data inversion imaging requires high speed and accuracy for forward modeling. For arbitrarily distributed susceptibility data on an undulated surface, we propose a fast 3D forward modeling method in the wavenumber domain based on (1) the wavenumber-domain expression of the prism combination model and the Gauss–FFT algorithm and (2) cubic spline interpolation. We apply the proposed 3D forward modeling method to synthetic data and use weighting coefficients in the wavenumber domain to improve the modeling for multiple observation surfaces, and also demonstrate the accuracy and efficiency of the proposed method.
. Fast 3D forward modeling of the magnetic field and gradient tensor on an undulated surface[J]. APPLIED GEOPHYSICS, 2018, 15(3-4): 500-512.
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2018, Vol. 15 
