Enhancing SAR image formation using superimposed FFT

This paper discusses the effect of superimposed-Fast Fourier Transforms on synthetic aperture radar (SAR) image formation. In a Fourier Transform, the band-limited property in measured signals causes relatively high sidelobes, which tends to corrupt the “target” or “Image” detected. One technique to reduce side-lobes is windowing; nonetheless, this will also have a broadening effect on the main-lobe. The proposed technique of superimposition attempts to reduce sidelobes while not broadening the target´s main-lobe much. Furthermore, the superimposition technique preserves the amplitude of the targets´ main-lobe while conventional sharpening techniques tend to distort it in one way or another. Results show minimal resolution loss, significant sidelobe reduction and negligible distortion of peak position and amplitude from the original spectrum.