A SAR sidelobe suppression algorithm based on modified spatially variant apodization

The existing spatially variant apodizations (SVAs) either cannot depress the sidelobes effectively or reduce the energy of the mainlobe. To improve this, a modified SVA (MSVA) is put forward in this paper, which expands the traditional filter from 3-taps to 5-taps and sets relevant parameters according to different sampling rates to get the excellent result that satisfies constrained optimization theory. A method for synthetic aperture radar (SAR) sidelobe control based on MSVA is presented, which applies MSVA to range compression and azimuth compression to control sidelobes. This method which is available for any Nyquist sampling rate can both depress the sidelobes effectively and keep the energy of the mainlobe and the resolution of the image. The method can reduce sidelobe levels more effectively than classical amplitude weighting while maintaining the image resolution, as demonstrated by the result of the experiment.