Range Non-linearities Correction in FMCW SAR

The limiting factor to the use of Frequency Modulated Continuous Wave (FMCW) technology with Synthetic Aperture Radar (SAR) techniques to produce lightweight, cost effective, low power consuming imaging sensors with high resolution, is the well known presence of non-linearities in the transmitted signal. This results in contrast and range resolution degradation, especially when the system use is intended for long range applications, as it is the case for SAR. The paper presents a novel processing solution, which completely solves the non- linearity problem. It corrects the non-linearity effects for the whole range profile at once, differently from the algorithms described in literature so far, which work only for very short range intervals. The proposed method operates directly on the deramped data and it is very computationally efficient.