ZHANG YanHui,
WENG AiHua,
LI ShiWen et al
.2019.Estimation of C-responses of geomagnetic depth sounding based on global smooth constraint Chinese Journal of Geophysics(in Chinese),62(5): 1898-1907,doi: 10.6038/cjg2019M0199
基于全局光滑约束的地磁测深C-响应估计
张艳辉, 翁爱华, 李世文, 李建平, 杨悦, 唐裕
吉林大学地球探测科学与技术学院, 长春 130026
Estimation of C-responses of geomagnetic depth sounding based on global smooth constraint
ZHANG YanHui, WENG AiHua, LI ShiWen, LI JianPing, YANG Yue, TANG Yu
College of Geo-Exploration Science and Technology, Jilin University, Changchun 130026, China
Abstract:C-responses of geomagnetic depth sounding (GDS) contain effective information on the internal structure of the earth, so the accurate C-responses estimation is very important for revealing the accurate electrical structure in the earth. To this end, a new method to estimate the C-responses of GDS is proposed in this paper. Different from the previous single frequency estimation methods, this approach simultaneously estimates the C-responses of all frequencies based on the continuous smoothing characteristic of the adjacent frequency. First, the linear equations are constructed from the observed Hr and Hθ based on the Z/H method. In order to enhance the stability of the equations and overcome the influence of noise, the estimated C-responses are required to satisfy the smoothness condition, and the unconstrained C-responses estimation is transformed into an optimization problem of the damped least squares theory. The tests of synthetic data and real observational data indicate that the smooth constrained technology can obtain more reasonable and continuous curves than the traditional methods. Although the regularization parameter has an important influence on the estimation, the optimal regularization parameter determined by L-curve and V-curve methods can obtain the best C-responses while ensuring the authenticity of the data. The C-responses obtained by this method lay the foundation for improving the reliability of the inversion results, and provide technical support for the high-resolution electrical structure of the earth's interior by using C-responses of more observatories.
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