5824

5439

كارشناسي ارشد

مخابرات﴿ميدان﴾

اصفهان: دانشگاه صنعتي اصفهان، دانشكده برق و كامپيوتر

1389

نه،102ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

صفيان

5/2/90

برجي، زيدآبادي نژاد

مهندسي برق و كامپيوتر

ID5439

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

103 Isfahan University of Technology Department of Electrical and Computer Engineering Linear Sampling Method in Solving two dimensional Inverse Scattering Problem Abstract Scattering problems in electromagnetic are divided in the two main branches 1 Direct scattering problem and 2 Inverse scattering problem In direct scattering problems the shape material and position of the scatterers are known In this case we can write a partial differential equation inside and outside of scatterer and then enforce boundary conditions so the field will be clear inside and outside of the scatterer In inverse scattering problem we should measure the scattered field from the object to obtain some kind of information about the shape and or material and the position of it there are several applications for solving inverse scattering problems in medical science non destructive microwave testing and military applications generally there are two kinds of methods for solving inverse scattering problems Quantitative and qualitative Quantitative techniques concerns with minimizing a parameter to obtain an unknown properties of the objects So it is important to use an optimization technique However qualitative methods are concerned with solving an inverse problem in applied mathematics Qualitative methods are faster than the quantitative ones However the former in contrast with the latter are not able to realize the material and are used just for detecting the shape Linear sampling method is a qualitative method which is interested in recent years The method can be implemented easily and worked in single frequency In solving an inverse problem we always need to apply a kind of regularization method to gain a regularized solution in linear sampling method in fact we solve far filed equation which relates a quantitative parameter to the far scattered field However the number of transmitter and receiver antennas working frequency and noise in measured data have a large effect on the quality of reconstruction In this project after implementing linear sampling method we investigate the effect of considered parameters on the result then we present a comparison between reconstructing using TE and TM incident field polarization After that the effect of the earth near the object on the results is considered In the most important part of this project we note how to detect an object metallic or dielectric buried in a larger dielectric one We show that it is important to select an appropriate frequency to eliminate the scattered field from external dielectric to reach to the internal object

صفيان

برجي، زيدآبادي نژاد