Estudo da influência de parâmetros de simulação em algoritmos de detecção de alvos para imagens SAR VHF UWB

Abstract

Synthetic aperture radars (SAR) stand out for their application in environmental and terrestrial monitoring systems. This application is convenient because of the characteristic of this system in providing, when desired, high resolution images as well as being less susceptible to climatic conditions when compared to optical systems. This type of system, when used at low frequencies, has a resolution similar to the wavelength of the signal, so as to be suitable for applications in forest regions, since this resolution softens the influence, in the image formation, of foliage, branches, among other structures. In this scenario, the SAR system CARABAS II (Coherent All RAdio BAnd Sensing) is inserted, which will be the object of study of this work. The VHF (Very High Frequency) frequency band used by this system provides good penetration into the vegetation and to some extent on the ground, making this device a system of high interest for military applications, or for the detection of camouflaged targets in forests or even obtaining topographic maps. Among the target detection algorithms used for this application, it is possible to emphasize the change detection algorithms, which are the focus of study of this work. Change detection algorithms aim to highlight variations between images in such a way as to differentiate the targets from other noise signals, clutter (echoes resulting from the data acquisition environment). Thus, this paper presents the study carried out on the influence of the main parameters used in the target detection algorithms for VHF Ultra-wideband (UWB) SAR systems. As a result of the study, we obtained an increase in terms of the probability of correctly detecting a target, as well as reducing the occurrence of false alarms.