Apostolos C. Raptis

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In this paper, we present a novel passive millimeter-wave (PMMW) imaging system designed using compressive sensing principles. We employ randomly encoded masks at the focal plane of the PMMW imager to acquire incoherent measurements of the imaged scene. We develop a Bayesian reconstruction algorithm to estimate the original image from these measurements,(More)
This paper analyzes heart rate (HR) information from physiological tracings collected with a remote millimeter wave (mmW) I-Q sensor for biometric monitoring applications. A parameter optimization method based on the nonlinear Levenberg-Marquardt algorithm is used. The mmW sensor works at 94 GHz and can detect the vital signs of a human subject from a few(More)
In this paper, we briefly describe a single detector passive millimeter-wave imaging system, which has been previously presented. The system uses a cyclic sensing matrix to acquire incoherent measurements of the observed scene and then reconstructs the image using a Bayesian approach. The cyclic nature of the sensing matrix allows for the design of a single(More)
Passive millimeter-wave (PMMW) imagers using a single radio-meter, called single pixel imagers, employ raster scanning to produce images. A serious drawback of such a single pixel imaging system is the long acquisition time needed to produce a high-fidelity image, arising from two factors: (a) the time to scan the whole scene pixel by pixel and (b) the(More)
This report describes the development of a microwave (MW) radar sensing and imaging system to remotely detect and locate gas leaks in natural gas pipelines. It contains theoretical and experimental results to show feasibility of the radar technique. The gas dynamics of the leak jet are modeled first to determine the plume geometry and the variation of gas(More)
—We present observations of microwave scattering from ambient room air ionized with a negative ion generator. The frequency dependence of the radar cross section of ionized air was measured from 26.5 to 40 GHz (Ka-band) in a bistatic mode with an Agilent PNA-X series (model N5245A) vector network analyzer. A detailed calibration scheme is provided to(More)
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