Radar imaging by using GTD near-field model and antenna array-factor

摘要

As one of the image processing method of radar sensor, it is most typical method which employs synthetic aperture radar (SAR) processing. In this paper we investigate radar image of scattering models by using an extended idea of array-factor (AF) in antenna theory. Applying phase difference between each element of the array becomes so-called phased array beam-forming and weighting to each element becomes adaptive beam processing [1], [2]. Also, regarding AF as near sources, it has been directly applied to far-field transforming algorithm [3]. Since AF is considered as a sum of delayed phase signals from each antenna element, we can construct image of the signal from the sum which depends on degree of phase matching between the receiving signal and its coordinate. This procedure is a kind of aperture synthesis, also known as delay and sum (DAS), especially in the field of ultrasound medical imaging and acoustics [4].