ISAR Imaging of Maneuvering Target Based on the Estimation of Time Varying Amplitude With Gaussian Window

Due to the maneuverability of target’s motion in the inverse synthetic aperture radar (ISAR) imaging, the Doppler frequency of the received signal has the nonlinear time-varying characteristic. Under the circumstances, it is accurate enough to model the received signal of each range bin as a multicomponent quadratic frequency-modulated (QFM) signal. In this paper, the scaled Fourier transform (SCFT) is applied to obtain the phase parameters of the QFM signal. Owing to the phenomenon of the scatterers’ migration through resolution cell (MTRC) and the change of attitude angle, the amplitude of the received signal is no longer constant but time-varying. Thus, a novel and precise method using the adaptive Gaussian window is presented to estimate the time varying amplitude of the received signal. After that, the corresponding ISAR imaging algorithm is presented consequently. The validity of the proposed method is demonstrated by the simulated and real-data ISAR results.