Suppression of Ghost Images of Strong Point-Like Targets in SAR Imagery

Due to the characteristics of the practical antenna patterns, there exist non-bandlimited signals from the sidelobes for synthetic aperture radar (SAR), which will result in ghost images in azimuth, especially for strong targets. This paper presents a novel suppression method for the ghost images of the strong point-like targets without increasing the pulse repetition frequency (PRF) or the number of the receive channels. Firstly, the non-bandlimited signals of each strong point-like target are obtained along its range history in the range-compressed signals. Then, the non-bandlimited signals are converted into the single frequency signals by deramp processing. Finally, a finite impulse response (FIR) is designed based on convex optimization to filter out the non-bandlimited signals and suppress the ghost images. Theoretical analysis and experiments demonstrate the feasibility of the proposed method.