Spatially variant apodisation for sidelobe suppression in near range radar imagery

High sidelobes greatly reduce the quality of radar imageries. Under the near range condition, sidelobe suppression becomes more intractable due to the space-variant characteristic of the wavenumber spectrum. The Spatially variant apodisation (SVA) method is extended for sidelobe suppression in near range radar imageries. The method first multiplies the original image by a compensation term so that the wavenumber spectra of all targets shift to the same central position. Then, a spatially variant weighting scheme with the changeable weighting range is adopted to suppress sidelobes. Based on these two procedures, the method effectively overcomes the effect of the space-variant characteristic of the wavenumber spectrum. Similar to the original SVA method, the proposed method can greatly suppress the sidelobe while maintaining the mainlobe width. In addition, since it is implemented in the image domain, this method is a post-processing operation and is very conducive to parallel processing. Both 2-D and 3-D measured data verify its effectiveness.