Near-Field Radar Principles and Low Contrast Target Imaging Methods

点击翻译按钮获取中文摘要

Radar is becoming a widely applied sensor technology for modern applications such as the Internet of Things (IoT) location based services, hand gesture interaction to control wearable electronics - virtual tools, and as an imaging tool for medical diagnosis, monitoring seed germination, oil well monitoring, and tunnel boring machine guidance and control. Most of these applications are very short range, sometimes within a few centimeters (near-field), and demand high precision ranging and image resolution.******In radar methods, travel time of the reflected wave are considered for sensing and imaging. In measurements the radar and target are positioned at a far distance. The fundamental limitation of this imaging method is diffraction limit. To improve the image resolution beyond the diffraction limit, some of the energy from the target proximity should be captured which is defined as a near-field interaction between the radar and the target.******In radar near-field the electric and magnetic fields are very complex either in the frequency domain or in time domain. In the near-field of a time domain radar the pulse shape is not stable, and the pulse propagation is faster than the speed of light. To take the advantage of near-field interaction to improve the detection and imaging capability of the radar, a thorough understanding of the near-field principles and imaging algorithms are needed.******My research program will develop principles and theoretical framework for the near-field radars, methods for near-field imaging, and implement various imaging applications. The goals of the research are to understand the physics of time-domain near-field radars and to develop the radar systems for short range applications that achieve image resolutions beyond the diffraction limit. The application for the research are to (i) Develop a technology, by exploiting near-field interaction of the radar with the target, to monitor small perforations in narrow metal pipes and oil wells, (ii) Develop a technology to image the nonlinear targets such as electronic components improvised explosive devices (IEDs) and their detonators, (iii) Develop microwave imaging technology (MIT) to image low contrast dielectric discontinuities where the difference in dielectric constant is lower than 10%.******This research bridges the technology gap between the traditional far-field radar imaging and microscopic techniques by improving the radar imaging resolution beyond the traditional expectations, while being cost effective, easy to operate, and providing near-real time imaging for various applications. They can bring revolution in medical diagnosis tools, virtual tools to control wearable electronics, and sensors for modern Internet-of-Things based solutions.*****************