Fransdimensional Bayesian inversion of timedomain airborne EM data  

作　　者：Gao Zong-Hui Yin Chang-Chun Qi Yan-Fu Zhang BO Ren Xiu-Yan Lu Yong-Chao 

机构地区：[1]College of Geo-Exploration Sciences and Technology, Jilin University, Changchun 130026, China [2]School of Geology and Survey Enginneering, Changan University, Xi'an 710054, China

出　　处：《Applied Geophysics》2018年第2期318-331,365,共15页应用地球物理（英文版）

基　　金：This paper was financially supported by the Key National Research Project of China （Nos. 2017YFC0601900 and 2016YFC0303100）, and the Key Program of National Natural Science Foundation of China （No. 41530320） and Surface Project （No. 41774125）.

摘　　要：To reduce the dependence of EM inversion on the choice of initial model and to obtain the global minimum, we apply transdimensional Bayesian inversion to time-domain airborne electromagnetic data. The transdimensional Bayesian inversion uses the Monte Carlo method to search the model space and yields models that simultaneously satisfy the acceptance probability and data fitting requirements. Finally, we obtain the probability distribution and uncertainty of the model parameters as well as the maximum probability. Because it is difficult to know the height of the transmitting source during flight, we consider a fixed and a variable flight height. Furthermore, we introduce weights into the prior probability density function of the resistivity and adjust the constraint strength in the inversion model by changing the weighing coefficients. This effectively solves the problem of unsatisfactory inversion results in the middle high-resistivity layer. We validate the proposed method by inverting synthetic data with 3% Gaussian noise and field survey data.为改善反演效果,获得全局最小解,减小反演结果对初始模型的依赖程度,本文将变维数贝叶斯反演应用于时间域航空电磁数据反演。变维数贝叶斯反演方法在贝叶斯方法基础上利用可逆跳跃马尔科夫链蒙特卡洛方法(RJMCMC)实现反演模型层数的变化。这种方法根据建议分布并利用蒙特卡洛方法充分搜索模型空间进行随机采样。只统计同时满足数据拟合要求和接受概率的候选模型,受初始模型影响小,收敛稳定,反演结果可靠,最终可获得反演模型的概率分布和不确定度信息。由于实际飞行中发射源高度很难精确测量,因此本文在反演过程中将发射源高度分为不变和发射源高度变化两种情况。同时本文在电阻率先验概率密度函数中引入加权系数以调整对反演模型的约束强度,可有效地解决电阻率断面中间层反演效果不理想的问题。本文通过反演中心回线装置的H型和分离装置K型、HK型断面添加高斯噪声后的仿真数据以及实测数据,验证了变维数贝叶斯方法反演时间域航空电磁数据的有效性。

关 键 词：Time-domain airborne EM Bayesian inversion WEIGHING DECONVOLUTION 

分 类 号：TF3[冶金工程—冶金机械及自动化]