Seeing Through Walls: An Electromagnetic Perspective (for general audience)

Bldg: Pavillon Principal, B 600.16, la Galerie Rolland, 2500 Chem. de Polytechnique, Montréal, Quebec, Canada, H3T 1J4

The ability of electromagnetic waves to penetrate through various building materials, together with advances in design of ultra-wideband compact radar modules, has made see-thru-wall technology, also known as Through-the-wall radar imaging (TWRI), of increasing importance in a wide range of both civilian and defense applications. In this lecture, an overview of various TWRI technologies, including the latest research in several areas important in the design of TWRI systems, will be presented. Electromagnetic-based techniques for wall parameter estimation to mitigate the adverse wall effects and enhance the efficient imaging and classification of targets within and/or behind walls will be discussed. For efficient imaging, details of fast polarimetric and tomographic based imaging algorithms for both 2D and 3D scenarios will be given, and imaging results for various realistic scenarios using both numerical simulations and laboratory measurements will be presented, Development of wideband and ultrawideband antenna arrays, which are essential in successful implementation of see-thru-wall technology, together with hardware descriptions of two constructed portable systems will conclude the presentation. Throughout, I will include a personal perspective from my own two-decade journey in this interdisciplinary research area. Speaker(s): Prof. Ahmad Hoorfar, Bldg: Pavillon Principal, B 600.16, la Galerie Rolland, 2500 Chem. de Polytechnique, Montréal, Quebec, Canada, H3T 1J4

Real Time and Sparse Reconstructed Radar Imaging Through Stratified Media

Bldg: Pavillon Principal, B 600.16, la Galerie Rolland, 2500 Chem. de Polytechnique, Montréal, Quebec, Canada, H3T 1J4

The problem of imaging of objects within or through multilayered dielectric media appears in many areas, including those in ground-penetrating radar (GPR) imaging, through-the-wall radar imaging (TWRI), intra-wall and subsurface imaging, and medical imaging. These general areas cover many important defense and civilian applications such as those in counterterrorism and law enforcement operations, firefighting, earthquake rescue missions, detection of buried subsurface objects and minerals in GPR, millimeter wave imaging of concealed weapons and contraband carried by personnel, to name a few. In many situations, however, the dielectric media induce shadowing effects on targets, resulting in image degradation and errors in geo-locating or, possibly, complete masking of targets. Furthermore, in most practical situations the imaging of targets should be done in real-time, requiring the development of fast data acquisition schemes as well as highly efficient microwave imaging techniques that can fully account for wave propagation through various dielectric layers or walls. In this lecture, a comprehensive overview of various image reconstruction techniques for objects in stratified media will be given for both SAR-based and multiple-input multiple-output (MIMO) based systems, and for both real-time imaging and sparsity-based imaging scenarios. For the former, we will describe the use of efficient 2D and 3D Diffraction Tomography (DT) techniques which use first order Born approximation together with successive implementations of spatial fast-Fourier transform (FFT) and inverse-FFT (IFFT), to arrive at high-resolution images. Such fast-imaging techniques, however, do not address the problem posed by long data acquisition time associated with most microwave-imaging scenarios. To address this problem, assuming a sparse target space, one can resort to the use of Compressive Sensing (CS) to significantly reduce the number of antennas and/or collected frequency points. In our implementation of CS, the wall or multilayered media effects are accurately and efficiently accounted for in the sparse-image reconstruction through the use of approximate expressions for the Green’s functions of multi-layered lossy dielectric medium. In particular, the use of total variation minimization (TVM) and its advantages over the l1-norm minimization, which is often used in the standard radar implementation of CS, will be detailed. Numerical and experimental results for DT-based and CS-based radar imaging in various GPR and TWRI scenarios will be given in the presentation. Speaker(s): Prof. Ahmad Hoorfar, Bldg: Pavillon Principal, B 600.16, la Galerie Rolland, 2500 Chem. de Polytechnique, Montréal, Quebec, Canada, H3T 1J4

InAs/InP Quantum-Dash Mode-Locked Laser For Duplex Radio Over Fiber Links

Virtual: https://events.vtools.ieee.org/m/388262

An InAs/InP quantum-dash mode-locked laser (QD-MLL) with phase-locked comb lines is an excellent optical source and a microwave source for, respectively, optical and wireless transmission. In this talk, a duplex radio over fiber (RoF) link using a QD-MLL for RoF transmission is reported. A few implementation issues including phase noise impairment, MIMO transmission, and photonic integrated implementation will be discussed. RoF links with integrated sensing and communication (ISAC) functions for next generation wireless communications (6G) applications will also be discussed. Laser à verrouillage de mode InAs/InP tirets quantiques (Quantum-Dash) pour radio duplex sur liaisons fibre optique Un laser à verrouillage de mode quantique InAs/InP (QD-MLL) avec des lignes de peigne à verrouillage de phase est une excellente source optique et une source micro-ondes pour, respectivement, la transmission optique et sans fil. Dans cet exposé, une liaison radio duplex sur fibre (RoF) utilisant un QD-MLL pour la transmission RoF est rapportée. Quelques problèmes de mise en œuvre, notamment la dégradation du bruit de phase, la transmission MIMO et la mise en œuvre photonique intégrée, seront abordés. Les liens RoF avec des fonctions intégrées de détection et de communication (ISAC) pour les applications de communications sans fil (6G) de nouvelle génération seront également abordés. Co-sponsored by: National Research Council, Canada. Optonique. Speaker(s): Prof. Jianping Yao (University of Ottawa), Virtual: https://events.vtools.ieee.org/m/388262

Webinar: OpenPMU, PTP, and Time Synchronised Sampled Values – The Data Hoarder’s Approach

Virtual: https://events.vtools.ieee.org/m/388536

Webinar presented by the IEEE Montreal Section Power & Energy Chapter and IEEE Northern Canada PES/IAS Joint Chapter. Abstract: "When you can measure what you are speaking about and express it in numbers, you know something about it." - Lord Kelvin. Synchronized measurement technology, specifically the Phasor Measurement Unit (PMU), has provided tremendous insight into power system phenomena over the last few decades. However, the PMU is an instrument not well understood by many who utilize its measurements. The time-synchronized phasor, or synchrophasor, is a double-edged sword. On one hand, it has made it possible to apply classical methods of power system analysis to "real" data from actual systems. On the other hand, the synchrophasor eliminates all the nuances of the voltage or current waveform present in the sampled values from which it is estimated. What if we keep all of the time-synchronized sampled value (TSSV) data and use that for our studies? Building machines capable of doing this is more than feasible. This talk will discuss the approaches and challenges that engineers pursuing this strategy face, particularly the not-so-small matter of the many terabytes of data such a system will create, with "needle in a haystack" levels of useful information. The talk will describe an effort on the island of Ireland to build a national system to record TSSV and also synchronize using PTP instead of GNSS and its "space-based" vulnerabilities. Speaker(s): Dr. David Laverty, Reader (Full Professor) of Queen’s University Belfast Virtual: https://events.vtools.ieee.org/m/388536