Software-Oriented Adjustable Concentration of ISAR Images—Toward Super-Resolution

This article presents the concept of adjustable inverse synthetic aperture radar (ISAR) image concentration using the Levenberg-Marquardt optimization algorithm and the windowed 2-D Fourier transform (W2D-FT). A recently developed method for strong ISAR focusing is revised, allowing the user to obtain a stronger or weaker concentration of energy reflected from scatterers. As a result, the target image obtained using the proposed method can be of an intermediate resolution, leading to a target shape perception that outperforms other methods. The proposed technique fits the current software-oriented ISAR image resolution trend, as the whole method is based on efficient implementation and can work in real-world systems. The presented technique is validated using both simulated and real-life data employing bistatic radar for target imaging. The open-source MATLAB code for the software-oriented ISAR image improvement is also provided.