A Ship Target Calibration Method Based on GRFT

Calibration is a key technology in ISAR (Inverse Synthetic Aperture Radar) processing. Traditional calibration techniques are typically aimed at uniformly oscillating targets. However, for sea surface moving targets, their oscillation exhibits significant sinusoidal characteristics, reducing the performance of traditional algorithms. To address this issue, this paper proposes a GRFT-based (Generalized Radon-Fourier Transform) calibration method for sea surface ships. Based on the construction of the ship's echo model, the relationship between the motion parameters and the calibration-required angular parameters is established. The PSO-GRFT-CLEAN (Particle Swarm Optimization, PSO) algorithm is then used to estimate the motion parameters of the two sub-apertures, completing the calibration of the ISAR image. Simulations on ship models demonstrate the effectiveness of the algorithm.