Sidelobe apodization in Fourier imaging

Spatially variant sidelobe apodization (SVA) is a technique that reduces sidelobe levels in a Fourier image while maintaining the image resolution that would be obtained using the rectangular window. The method has been successfully used in inverse synthetic aperture radar (ISAR) imaging. In general, sidelobe apodization techniques can be used whenever a finite amount of data is processed by a discrete-time Fourier transform. Thus, the technique can be extended to magnetic resonance imaging (MRI) and time-frequency analysis. We explore the impact of sidelobe apodization on these Fourier imaging techniques. The characteristics of the data processed in these applications present singular challenges. In one instance the data consist of reflectivity samples from high intensity airborne scattering structures. In another case the data consist of signals with high signal-to-noise ratios in which intensities decay with time. A third instance is that of data consisting of nonstationary and transitory signals. Advantages and disadvantages of sidelobe apodization are discussed.