Suchergebnisse

A novel, real-time, two-dimensional method to find the shape of a body from its scattered electric fields is presented. The method is based on a unique combination of the information obtained from the target using the SAR formulation with a novel fast model-based inversion. In the first step, a fast implementation of the SAR inversion is used to recover an initial estimate of the body shape. Secondly, the phase and amplitude of the SAR image are used to extract a set of first guess contours close to the actual position of the body under test. In a third step, these contours are used as a starting point for a model-based inversion in order to disregard the contours that do not match the body profile and to improve the final result. Resolution of less than half of a wavelength for the proposed method is achieved using representative simulation results and measured data ; U.S. Department of Homeland Security [2008-ST-061-ED0001]; Ministerio de Economia y Competitividad of Spain/FEDER [CSD2008-00068, TEC2011-24492/TEC]; Galician Regional Government under Plan I2C

This work develops compressed sensing techniques to improve the performance of an active three dimensional (3D) millimeter wave imaging system for personnel security screening. The system is able to produce a high-resolution 3D reconstruction of the whole human body surface and reveal concealed objects under clothing. Innovative multistatic millimeter wave radar designs and algorithms, which have been previously validated, are combined to improve the reconstruction results over previous approaches. Compressed Sensing techniques are used to drastically reduce the number of sensors, thus simplifying the system design and fabrication. Representative simulation results showing good performance of the proposed system are provided and supported by several sample measurements ; This work was supported in part by CenSSIS, the Gordon Center for Subsurface Sensing and Imaging Systems NSF ERC Program (Award number EEC-9986821); by the Science and Technology Directorate, U.S. Department of Homeland Security under the Award Number 2008-ST-061-ED0001; by the Xunta de Galicia under Plan I2C (2011-2015); by the European Union - FP7 under the project 600849 (INSIDDE); and in part by the Ministerio de Economía y Competitividad of Spain/FEDER under projects CONSOLIDER-INGENIO CSD2008-00068 (TERASENSE), and TEC2011-24492/TEC (iSCAT)

This paper presents a novel interrogation system that combines multiple millimeter wave transmitters and receivers to create real-time high-resolution radar images for personnel security screening. The main novelty of the presented system is that the images can be created as the person being screened continuously moves across a corridor where the transmitters and receivers, working in a fully coherent architecture, are distributed. As the person moves, the transmitters and receivers are sequentially activated to collect data from different angles to inspect the whole body. Multiple images, similar to video frames, are created and examined to look for possible anomalies such as concealed threats. Two-dimensional (2-D) and three-dimensional (3-D) setups have been simulated to show the feasibility of the proposed system. The simulation results in 2-D have been validated using measurements ; Ministerio de Ciencia e Innovacin of Spain/FEDER under project MIRIIEM-TEC2014-54005-P, in part by the Gobierno del Principado de Asturias through the PCTI 2013-2017, GRUPIN14-114, in part by the Spanish Government under project TACTICA, in part by the European Regional Development Fund (ERDF), in part by the Galician Regional Government under Projects CN2012/279, CN2012/260 (AtlantTIC) and the Plan I2C (2011–2015), and in part by the Science and Technology Directorate, U.S. Department of Homeland Security under the Award Number 2008-ST-061-ED0001