On the use of fractional autocorrelation to correct mismatches for chirp scale focusing for real SAR image formation

The fractional Fourier transform (FrFT) was shown to be an effective signal processing technique in many synthetic aperture radar (SAR) applications, and most recently, it was used to enhance the focusing capabilities of the chirp scaling algorithm (CSA). We propose the use of the fractional autocorrelation function in a local optimization procedure to detect mismatches in the fast-time linear frequency-modulated rate and correct these mismatches with the FrFT before CSA processing. Additionally, we enhance slow-time processing with the FrFT in order to maximize the contrast of targets in each range-bin. As we will demonstrate using SAR images, this processing increase SAR image quality.