By Topic

Two nonlinear inverse methods for electromagnetic induction measurements

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

2 Author(s)
Zhong Qing Zhang ; Dept. of Electr. & Comput. Eng., Duke Univ., Durham, NC, USA ; Qing Huo Liu

The authors develop two nonlinear inverse methods to reconstruct the conductivity profile from electromagnetic induction (EMI) measurements: the improved two-step inverse method based on the extended Born approximation (EBA) and the combination of the EBA and the contrast source inversion (CSI) method. In the first method, the nonlinear problem is recast as a two-step linear inversion and is solved by using the extended Born approximation. The authors improve this method with the fast Fourier transform (FFT) algorithm and by a conjugate-gradient optimization procedure. For a problem with N unknown pixels and ill measurement data points, the computational time of this inverse EBA procedure is reduced to O(MN) in the first step (i.e., the underdetermined linear problem) and to O(Nlog2N) in the second step (i.e., the well-determined linear problem) using the newly developed FFT-EBA method. Furthermore, the memory requirement is reduced to O(MN) (MT is the number of transmitters). In the second inverse method, they apply the contrast source inversion (CST) method, but use the two-step linear inversion result as the initial solution. By using FFT, the CPU time costs O(C1MN+C 2N log2 N) in each iteration of the CSI procedure. Numerical examples illustrate the effectiveness of these methods, even up to a high contrast of 100:1

Published in:

IEEE Transactions on Geoscience and Remote Sensing  (Volume:39 ,  Issue: 6 )