Multiple Electromagnetic Scattering by Randomly Distributed and
\n\nOriented Obstacles
\n\n
Abstract
\nScattering of electromagnetic waves by discrete, randomly distributed objects is addressed. In\ngeneral, the non-intersecting scattering objects can be of arbitrary form, material and shape. The\nmain aim of the talk is to calculate the coherent reflection and transmission characteristics of a\nfinite or semi-infinite slab containing discrete, randomly distributed scatterers. Typical\napplications of the results are found at a wide range of frequencies (radar up to optics), such as\nattenuation of electromagnetic propagation in rain, fog, and clouds etc. The integral\nrepresentation of the solution of the deterministic problem constitutes the underlying framework of\nthe stochastic problem. Conditional averaging and the employment of the Quasi Crystalline\nApproximation lead to a system of integral equations in the unknown expansion coefficients. Of\nspecial interest is the slab geometry, which implies a system of integral equations in the depth\nvariable. Explicit solutions for tenuous media and low frequency approximations can be obtained for\nspherical obstacles. Some numerical simulations that relate to the homogenization problem are also\npresented.
Brief biography for Prof. Gerhard Kristensson
\nGerhard Kristensson received his B.S. degree in mathematics and physics in 1973, and the Ph.D.\ndegree in theoretical physics in 1979, both from the University of Göteborg, Sweden. In 1983, he\nwas appointed Docent in theoretical physics at the University of Göteborg.
\nDuring 1977-1984 he held a research position sponsored by the National Swedish Board for Technical\nDevelopment (STU) and he was Lecturer at the Institute of Theoretical Physics, Göteborg from 1980-
\n1984. In 1984-1986, he was a Visiting Scientist at the Applied Mathematical Sciences group, Ames\nLaboratory, Iowa State University. He held a Docent position at the Department of Electromagnetic Theory, Royal Institute of Technology, Stockholm during 1986-1989, and in 1989, he was appointed\nthe Chair of Electromagnetic Theory at Lund Institute of Technology, Sweden. He retired from his\nchair December 31, 2014, and he is now Professor Emeritus at Lund University.
In 1992, 1997 and 2007 he was a Visiting Erskine Fellow at the Department of Mathematics,\nUniversity of Canterbury, Christchurch, New Zealand. In fall 2015, he was a visiting scientist at\nthe Department of Mathematics, Colorado State University, CO, USA.
\nGerhard Kristensson has served as a member of the Board of Editors of Wave Motion, the Editorial\nBoard and the International Advisory Panel of Inverse Problems, and the Review Board of Journal of
\nElectromagnetic Waves and Applications and Progress in Electromagnetic Research.
He is a Fellow of the Institute of Physics, and during 1991-2014, he served as a board member of\nthe Swedish National committee of Radio Science (SNRV). From 1994-2005, he was the chairman of
\nCommission B of SNRV and Official Member of URSI, Commission B for Sweden. He was the chairman of\nSNRV during 2006-2014, and at the same time, he was the official representative for Sweden in the\nInternational Union of Radio Science (URSI).
Kristensson has a general interest in electromagnetic scattering problems (incl. inverse scattering\nproblems) and wave propagation in inhomogeneous media. The propagation of transient electromagnetic
\nwaves in complex media, such as dispersive anisotropic and bi-isotropic media, are stressed. High\nfrequency scattering methods, asymptotic expansions, optical fibers, antenna problems, and mixture
\nformulas are also of interest, as well as radome design problems and homogenization of complex\nmaterials.
He has written five books and he is the author of over hundred journal and conference publications.
X-ALT-DESC;FMTTYPE=text/html:Multiple Electromagnetic Scattering by Randomly Distributed and
\n\nOriented Obstacles
\n\n
Abstract
\nScattering of electromagnetic waves by discrete, randomly distributed objects is addressed. In\ngeneral, the non-intersecting scattering objects can be of arbitrary form, material and shape. The\nmain aim of the talk is to calculate the coherent reflection and transmission characteristics of a\nfinite or semi-infinite slab containing discrete, randomly distributed scatterers. Typical\napplications of the results are found at a wide range of frequencies (radar up to optics), such as\nattenuation of electromagnetic propagation in rain, fog, and clouds etc. The integral\nrepresentation of the solution of the deterministic problem constitutes the underlying framework of\nthe stochastic problem. Conditional averaging and the employment of the Quasi Crystalline\nApproximation lead to a system of integral equations in the unknown expansion coefficients. Of\nspecial interest is the slab geometry, which implies a system of integral equations in the depth\nvariable. Explicit solutions for tenuous media and low frequency approximations can be obtained for\nspherical obstacles. Some numerical simulations that relate to the homogenization problem are also\npresented.
Brief biography for Prof. Gerhard Kristensson
\nGerhard Kristensson received his B.S. degree in mathematics and physics in 1973, and the Ph.D.\ndegree in theoretical physics in 1979, both from the University of Göteborg, Sweden. In 1983, he\nwas appointed Docent in theoretical physics at the University of Göteborg.
\nDuring 1977-1984 he held a research position sponsored by the National Swedish Board for Technical\nDevelopment (STU) and he was Lecturer at the Institute of Theoretical Physics, Göteborg from 1980-
\n1984. In 1984-1986, he was a Visiting Scientist at the Applied Mathematical Sciences group, Ames\nLaboratory, Iowa State University. He held a Docent position at the Department of Electromagnetic Theory, Royal Institute of Technology, Stockholm during 1986-1989, and in 1989, he was appointed\nthe Chair of Electromagnetic Theory at Lund Institute of Technology, Sweden. He retired from his\nchair December 31, 2014, and he is now Professor Emeritus at Lund University.
In 1992, 1997 and 2007 he was a Visiting Erskine Fellow at the Department of Mathematics,\nUniversity of Canterbury, Christchurch, New Zealand. In fall 2015, he was a visiting scientist at\nthe Department of Mathematics, Colorado State University, CO, USA.
\nGerhard Kristensson has served as a member of the Board of Editors of Wave Motion, the Editorial\nBoard and the International Advisory Panel of Inverse Problems, and the Review Board of Journal of
\nElectromagnetic Waves and Applications and Progress in Electromagnetic Research.
He is a Fellow of the Institute of Physics, and during 1991-2014, he served as a board member of\nthe Swedish National committee of Radio Science (SNRV). From 1994-2005, he was the chairman of
\nCommission B of SNRV and Official Member of URSI, Commission B for Sweden. He was the chairman of\nSNRV during 2006-2014, and at the same time, he was the official representative for Sweden in the\nInternational Union of Radio Science (URSI).
Kristensson has a general interest in electromagnetic scattering problems (incl. inverse scattering\nproblems) and wave propagation in inhomogeneous media. The propagation of transient electromagnetic
\nwaves in complex media, such as dispersive anisotropic and bi-isotropic media, are stressed. High\nfrequency scattering methods, asymptotic expansions, optical fibers, antenna problems, and mixture
\nformulas are also of interest, as well as radome design problems and homogenization of complex\nmaterials.
He has written five books and he is the author of over hundred journal and conference publications.
URL:https://www.ems.elektro.dtu.dk/calendar/2017/06/guest-lecture-by-prof-gerhard-kristensson-lund-university DTSTAMP:20260517T175700Z UID:{D2BBC0E9-7DFA-43CE-AF3E-0361BC28D4B1}-20170626T131500-20170626T131500 LOCATION: DTU Lyngby Campus, Ørsteds Plads Building 348 / room 227 END:VEVENT END:VCALENDAR