Processador SAR em tempo real para geração de imagens digitais

Abstract

The aim of this work was to develop a signal processor for synthetic aperture radars (SAR), operating in real-time, for applications that require imaging in a short period of time and independently of the atmospheric conditions.In that sense, a real-time SAR processor was implemented, which is based in a processing algorithm quite fast, to be used in airborne SAR system operating in X band.To the end of surveillance, the processor presents SAR images of a big area in real-time to an operator located in the aerial platform.The implemented algorithm works in the time domain and it uses the subaperture method to produce high quality, full resolution images.The subaperture processing principle consists of dividing the received SAR signal into subapertures, each corresponding to a small part of the total signal bandwidth.An approximation of the phase history correction is carried out in each subaperture, this approximated correction is done through an up/down-conversion of the signal, followed by a moving average operation.By adding all the subapertures coherently, a high resolution image is obtained.