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polarimetry
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Probing the Universe with Gravitational Microlensing
, Ph.D. Dissertation Sharif University of Technology ; Rahvar, Sohrab (Supervisor) ; Sajadian, Sedigheh (Co-Supervisor)
Abstract
Gravitational microlensing is one of the experimental tests to confirm the theory of general relativity. In this phenomenon, the light of the source star is deflected by the gravitational field of the foreground star which plays the role of the lens. As a result of this deviation, images of source star are formed on the sky plane. The observer records the light of the source star as a variable with time. The gravitational microlensing illustrates the possibility to discover extrasolar planets, study the atmosphere of stars, and probe the nature of Dark matter. In this thesis, at first, we introduce the basic concepts of gravitational microlensing and its history. Then by simulation of...
Improving the Quality of Standoff Millimeter-Wave Imaging by Using Polarimetry
, M.Sc. Thesis Sharif University of Technology ; Ahmadi Boroujeni, Mehdi (Supervisor)
Abstract
In recent years, the growing importance of imaging in the fields of medicine, security, food quality control, etc. has led to many investigations to find the most efficient imaging methods. In this thesis, the improvement of high frame-rate millimeter-wave stand-off imaging is investigated using the polarimetry method. The main objective of this study was to use Cx-pol scattered waves from rough surfaces, especially the edges of a Perfect Electric Conductor (PEC), to detect the edges of this object from the human body surface. Since the surface of the human body at the desired operating frequency (100 GHz) is almost flat, the background effect can be eliminated by analyzing the Cx-pol...