Entity

Time filter

Source Type


Cao C.-H.,Central South University | Cao C.-H.,Key Laboratory of Non ferrous Resources and Geological Detection | Tong X.-Z.,Central South University | Tong X.-Z.,Key Laboratory of Non ferrous Resources and Geological Detection | And 2 more authors.
Zhongguo Youse Jinshu Xuebao/Chinese Journal of Nonferrous Metals | Year: 2015

The frequency domain electromagnetic sounding calculation is a mathematically non-unique problem with instability because the observed data contain noise and its inherent incompleteness. Thus different models can fit the data from the same cross-section well. This problem can be solved by using regularization method. This study implements the two-dimensional inversion of frequency domain line source CSAET. The method of model parameters smoothness constraints and adaptive regularization technique was used to stabilize the inversion process. Besides, the adoption of adjoin equation approximate calculation method is more time efficient in the calculation of sensitivity. The numerical calculation results show that the use of synthetic data can contribute to the accurate inversion results. © 2015, Central South University of Technology. All right reserved. Source


Liu J.-X.,Central South University | Liu J.-X.,Key Laboratory of Non ferrous Resources and Geological Detection | Peng Y.-H.,Central South University | Peng Y.-H.,Key Laboratory of Non ferrous Resources and Geological Detection | And 3 more authors.
Wutan Huatan Jisuan Jishu | Year: 2014

The determination of a suitable regularization parameter is necessary to achieve both resolution and stability in process of DC resistivity sounding inversion of two -dimension. In this paper, we present an inversion scheme for DC resistivity data using self-adaptive regularization parameter with Active Constrained Balancing (ACB) approach. The regularization parameter varies spatially according to the spread function and is related to both the model parameters resolution matrix and the iteration number. The ACB approach assigns a higher value of regularization to low resolution. The varying regularization parameter obtained with the ACB approach is used to balance between the norm of data misfit and the norm of the model. The synthetic tests show that the inversion scheme with the ACB approach performs stable and convergence, and the inversion results can reflect accurately the subsurface geology structure. Source


Liu J.-X.,Central South University | Liu J.-X.,Key Laboratory of Non ferrous Resources and Geological Detection | Zhang W.,Central South University | Zhang W.,Key Laboratory of Non ferrous Resources and Geological Detection | And 4 more authors.
Wutan Huatan Jisuan Jishu | Year: 2014

Because of the highly efficiency of this method, large loop source transient electromagnetic method is widely used by geophysical prospecting workers. Based upon the basic theory, this article has deduced electromagnetic expressions over layered earth model induced by large loop source. Then the magnetic vertical components inside and outside the loop are computed by quadrature with extrapolation (QWE). Comparing with the results from fast hankel transform (FHT), both methods performed well for the imaginary component. And when the transmit loop was located few meters away from the model surface, the results of the two method performed well, but when the loop located on the surface, QWE performed better than FHT. Source


Cao C.-H.,Central South University | Cao C.-H.,Key Laboratory of Non ferrous Resources and Geological Detection | Liu J.-X.,Central South University | Liu J.-X.,Key Laboratory of Non ferrous Resources and Geological Detection | And 7 more authors.
Zhongguo Youse Jinshu Xuebao/Chinese Journal of Nonferrous Metals | Year: 2013

The inversion technique of CSAMT method which is widely used in the field of geophysical prospecting was investigated. Firstly, one-dimensional Bostick inversion method was used in the inversion of data measured in the field; secondly, the cross-section of one-dimensional inversion was taken as an initial cross-section model of the two-dimensional inversion since the probing depth determined by Bostick inversion is relatively accurate, and we Occam inversion method was used for positive inversion; thirdly, geological interpretation was concluded, which improves the accuracy of the initial geoelectric section model indirectly; at last, this data processing method was analyzed and a conclusion was drown while integrating the CSAMT survey results of eastern Kunlun Cu, Pb and Zn polymetallic ore. The results show that step by step inversion technique contributes directly to the survey result, which provides useful experience for future investigation. Source

Discover hidden collaborations