Hyperacuity in antenna systems

摘要

Hyperacuity of the human eye consists in the known capability to see very fine details far away from the limitations set by the number and size of its detectors. The authors of this paper have recently explained the hyperacuity of the human eye based on the use of the pupil diffraction before detection combined with a defined inverse problem. One of the most important concluding remarks of this study is the fact that, under some conditions, the inverse problem could be solved, meaning that some of the general rules used for designing imaging systems, including all the Synthetic Aperture Radar systems, could be reconsidered. Basically, if we are able to afford the inverse problem, we could assume some “blurring” in detecting samples, knowing that afterwards we would be able to restore the information, just by eliminating the known blur introduced at the detection process. In this case, we will try to apply this idea to improve radar applications. The angular resolution of a radar system is limited by the 3 dB beamwidth of the far field pattern. If we perform sampling at smaller angles, the obtained image will just be blurred by the radiation pattern of the system. Under certain conditions this blur could be removed by solving this inverse problem, and thereby restore a higher resolution image or signal. In this paper we will study the possibility to apply the concept of the visual hyperacuity to radar antenna systems, defining the conditions that these systems should satisfy, trying to find simpler and more robust designs.