Método de detecção de alvos para imagens SAR VHF de intensidade com resolução na ordem do comprimento de onda

Abstract

This document presents a study carried out to develop a target detection method for intensity wavelength resolution synthetic aperture radar (SAR) images. The studies presented in this work are supported by a literature review referring to the concepts used, encompassing information on synthetic aperture radar systems and a set of data from the SAR VHF CARABAS-II system, this set is composed of 24 SAR images, each one, containing 25 vehicles distributed under dense vegetation. The low frequency of operation of this system allows the partial visualization of these vehicles. In the course of this work, a method is developed that uses intensity SAR images, aiming at the detection of the targets present in it, minimizing the level of false alarms. Initially a proposal using the exponential bivariate distribution as a basis for the Likelihood-Ratio Test is considered and its results are exposed. A statistical study is carried out in order to obtain a faithful description of the background of SAR VHF images, where it was found that the ideal distribution is the bivariate Gamma distribution. The original method was adapted to use intensity difference images, using the bivariate Gamma distribution as the basis for the LRT. The results achieved are compared with renowned works in the literature, obtaining superior performance. Keywords: Target detection, SAR VHF UWB System, CARABAS-II, Likelihood-Ratio Test.