Date & Time:
Thursday, December 13, 2012; 12:00 PM
Electromagnetic (EM) remote sensing is a well-established modality for the detection, tracking, and identification of concealed targets. The degree of freedom offered by the operating frequency (and the associated propagation or induction regimes) make EM waves sufficiently versatile to interrogate both large as well as small structures, metallic as well as dielectric objects, in close proximity or further away. This wide flexibility has made EM remote sensing a modality of choice in many applications. This presentation will focus on two implementations of non-destructive and non-contact EM sensing. The first is based on a tomographic approach, whereby EM waves are used to infer material properties within the volume of accessible structures. The two examples to be discussed are breast cancer detection, i.e. locating areas of high vascularity in otherwise healthy biological tissues, and inspection of concrete structures, i.e. identifying volumetric material property variations to locate rebars and cracks. The second area we will discuss is that of subsurface target detection, with again two very different applications. The first pertains to ground penetrating radars with frequencies in the GHz aimed at the detection of buried weak dielectric scatterers, whereas the second focuses on the detection of metallic targets in the magnetic induction regime, for which much lower frequencies are used. In all these applications, the data collected by the appropriate hardwares are processed by combining fundamental EM concepts with inverse methods for parameter estimation. We will discuss both a deterministic method -- Gauss-Newton -- and a stochastic method -- Kalman filters for real time target detection.
Dr. Tomasz M. Grzegorczyk
Tomasz M. Grzegorczyk (SM'07) received his Ph.D. degree from the Swiss Federal Institute of Technology, Lausanne, in December 2000. From January 2001 to July 2007 he has been a research scientist with the Research Laboratory of Electronics (RLE), Massachusetts Institute of Technology (MIT), USA, and research affiliate with MIT until January 2011. During this period, while leading various research projects at the Center for Electromagnetic Theory and Applications, he had the opportunity to collaborate with Dr. Hara and Dr. Suwa of Mitsubishi Electric, Kamakura, Japan. In 2007 Dr. Grzegorczyk founded Delpsi LLC to provide consulting services in the areas of electromagnetic remote sensing to agencies such as MIT Lincoln Laboratory, the USA Engineer Research Development Center (ERDC), the Army Research Office, Dartmouth College, the Electronics and Telecommunications Research Institute (ETRI), South Korea. His research interests include the detection of subsurface targets, the use of electromagnetic induction for the detection and classification of unexploded ordnance, biomedical microwave imaging for breast cancer detection, microwave imaging for non-destructive assessment of concrete structures, optical binding and trapping, wave propagation in bianisotropic media and left-handed metamaterials. He is a senior member of IEEE and has served as editor and board member of two international peer-reviewed journals (the Progress In Electromagnetic Research and the Journal of Electromagnetic Waves and Applications) and one international conference (the Progress in Electromagnetics Research Symposium). He recently co-authored a book on metamaterials.