Fundamentals of Tomography and Radar
نویسنده
چکیده
Radar, and in particular imaging radar, has many and varied applications to security. Radar is a day/night all-weather sensor, and imaging radars carried by aircraft or satellites are routinely able to achieve highresolution images of target scenes, and to detect and classify stationary and moving targets at operational ranges. Different frequency bands may be used, for example high frequencies (X-band) may be used to support high bandwidths to give high range resolution, while low frequencies (HF or VHF) are used for foliage penetration to detect targets hidden in forests, or for ground penetration to detect buried targets. The techniques of tomographic imaging were originally developed in the context of medical imaging, and have been used with a number of different kinds of radiation, both electromagnetic and acoustic. The purpose of this presentation is to explore the application of tomographic imaging techniques at RF frequencies to a number of different applications in security, ranging from air defence to the detection of concealed weapons. Of particular interest is the use of ultra narrow band (UNB) transmissions with geometric diversity in a multistatic configuration to image moving targets. In the limit such transmissions could be CW, which would be particularly attractive for operation in a spectrallycongested environment. This arrangement effectively trades angular domain bandwidth for frequency domain bandwidth to achieve spatial resolution. Also of interest is the improvement in target classification performance afforded by multi-aspect imaging. The presentation will review the theory of tomographic imaging, then discuss a range of applications to the overall security problem, the relevant system configurations in each case, the achievable performance and critical factors, and identify promising areas for future research.
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تاریخ انتشار 2005