6376

5950

كارشناسي ارشد

مخابرات

اصفهان: دانشگاه صنعتي اصفهان، دانشكده برق و كامپيوتر

1390

نه،60ص.: مصور،نمودار

ص.ع.به فارسي و انگليسي

ابوالقاسم زيدآبادي

امير برجي

6/9/90

مهندسي برق و كامپيوتر

ID5950

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Inverse Scattering of Dielectric and Conducting Objects Based on Nonradiating Subspace Recon struction Hamid Reza Siampour h siampour@ec iut ac ir September 17 2011 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Language Persian Degree M Sc Thesis Supervisor Dr Abolghasem Zeidaabadi Nezhad zeidabad@cc iut ac irAbstractElectromagnetic inverse scattering is a problem including of detecting locating shape finding and imagingof the unknown objects by using scattered fields and Maxwell s equations There are different methods forsolving inverse scattering problems which one may group them under qualitative and quantitative titles Inthis thesis modified subspace optimization method SOM with sequential quadratic programming SQP algorithm called SQP SOM for inverse scattering of dielectric conducting and mixed objects which arelocated in different mediums such as free space inhomogeneous background and stratified media isproposed as an accurate and fast quantitative reconstruction method and the effect of nonradiating NR current induced on the scatterer onto renovation process is evaluated For this the direct scattering problemfor each case is formulated by a proper numerical method such as coupled dipole method CDM method ofmoment MoM finite elements boundary integral FE BI and electric field integral equations EFIE andthe corresponding external mapping operator has been spectral analyzed by singular value decomposition SVD technique to determine the radiating and NR singular vectors For expanding the induced currentspace the coefficients of the NR singular vectors have been dependent on the unknown components of thescatterers with least squares procedure This analysis is presented for mixture of dielectric and conductingscatterers and the related equations have been extracted for the first time For reconstructing the unknownscatterers the objective function has been constructed based on induced current residue and data scatteringmismatch and minimized by SQP Also to evaluate the effect of NR current for imaging the radiatingobjective function is defined by eliminating of NR part of the induced current The reconstructed results fromSQP SOM are successful for detecting locating shape finding and imaging levels Comparison with theresults of radiating objective function indicates that NR current reconstruction is necessary for accurateimaging of scatterers KeywordsInverse Scattering nonradiating NR current SQP SOM singular value decomposition SVD FE BI stratified media radiating objective function

ابوالقاسم زيدآبادي

امير برجي