Fast forward modelling of gravity anomalies of two-dimensional bodies of arbitrary shape and density distribution?
Chen Xin, Chen Long-Wei, Xiong Bin, and Luo Tian-Ya
1. College of Earth Sciences, Guilin University of Technology, Guilin 541006, China
2. Bowen College of Management, Guilin University of Technology, Guilin 541006, China
Abstract：
A spatial domain high-precision and fast algorithm is presented for forward modelling of gravity anomalies of two-dimensional (2D) bodies of arbitrary shape and density distribution. The new algorithm takes advantage of the convolution property of the expression for 2D gravity anomalies, uses a rectangular cell as a grid subdivision unit, and then 2D bodies with irregular cross section is approximated by the combination of 2D bodies with rectangular cross section. The closed-form expression is applied to calculate the gravity anomalies of the combination of the 2D bodies with rectangular cross section. To improve the computation efficiency, the new algorithm invokes a fast algorithm for the implementation of Toeplitz matrix and a vector multiplication. The synthetic 2D models with the rectangular and circular cross sections and constant and variable densities are designed to evaluate the computational accuracy and speed of the new algorithm. The experiment results show that for a grid subdivision with 10000×10000 elements, the computation costs less than 6 seconds. Compared with the traditional forward modelling methods, the proposed method has significantly improved the computational efficiency while guaranteeing the computational accuracy.
. Fast forward modelling of gravity anomalies of two-dimensional bodies of arbitrary shape and density distribution?
[J]. APPLIED GEOPHYSICS, 2018, 15(3-4（2）): 657-667.
2018, Vol. 15 
