A Space-Variant Sidelobe Suppression Method for Short-Range SAR Imaging

In this letter, a space-variant sidelobe suppression method for short-range microwave synthetic aperture radar (SAR) imaging system is proposed. The space-variant characteristics of local spectrum of SAR imaging results are analytically analyzed, taking the sector shape and uneven weighting factors of the spectrum support into consideration. Accordingly, a space-variant spectrum windowing method is designed. Furthermore, windowing operations in the wavenumber domain are converted to the weighting operations in the aperture domain for SAR signals using the principle of stationary phase, to avoid the computationally intensive space-variant convolution calculations in the spatial domain. Compared with the traditional methods in short-range settings, the sidelobes of imaging results are substantially suppressed with better effective field-of-views. The sidelobe suppression performance of the proposed method is validated with numerical simulations and experiments.