Estimating parameters of ship's echoes using matching Fourier transform

To improve the inverse synthetic aperture radar (ISAR) imaging quality with maneuvering un-cooperative ships, echoes were regarded as multi-components of linear frequency modulated (LFM) signals. The matching Fourier transform is a new technique for parameter estimation of LFM signals. Based on the principle of matching Fourier transforms, asymptotic statistical results were derived for the parameters estimated in this paper. The mean-squared error of the amplitude, initial frequency and frequency modulation rates approached the low bound of the Monte Carlo simulation. These Monte Carlo results supported the theoretical results. Finally, Doppler parameters of the ships were accurately estimated to get high resolution instantaneous images, deriving both shape and position. Raw data results verified this approach.