Parameterized two-dimensional representation for multicomponent cubic phase signals and its application in ISAR imaging of fluctuating ship

The cubic phase signal (CPS) can be determined by two physical quantities, the chirp rate and quadratic chirp rate. With this characteristic, this paper proposes the parameterized two-dimensional representation (PTDR), which can be seen as an extension of the chirp rate-quadratic chirp rate distribution (CRQCRD). The goal of the PTDR is to accurately estimate parameters of multicomponent CPSs under low signal-to-noise ratios (SNRs). The PTDR is simple and can be implemented by using the complex multiplication, fast Fourier transform (FFT) and nonuniform FFT (NUFFT). In this paper, the computational cost, resolution, cross term suppression and anti-noise performance are analyzed for the PTDR. With several synthetic examples, comparisons with other five algorithms are performed and demonstrate that the PTDR can achieve higher resolution, cross term suppression and anti-noise performance with a moderate computational cost. Finally, the PTDR is employed to reconstruct inverse synthetic aperture radar (ISAR) image of the fluctuating ship and the real radar data simulations validate the effectiveness of the PTDR-based ISAR imaging algorithm.