High-Resolution ISAR Imaging for Maneuvering Targets Based on Iterative Adaptive Processing

Abstract

Inverse synthetic aperture radar (ISAR) imaging for maneuvering targets undergoing significant angular motions in a high-resolution radar system is a complicated task due to the presence of time-varying Doppler phases, resulting in the substantial performance degradation by using the conventional range-Doppler (RD) algorithm. In this paper, a novel range instantaneous Doppler (RID) technique based on high-resolution time-frequency distribution (TFD) is proposed to realize the ISAR imaging for maneuvering targets with complex phase fluctuation. After motion compensation, the target signal in a range unit is transformed into high-resolution time-frequency domain by means of the short-time iterative adaptive approach (STIAA), which can avoid the troubled cross-term interference and effectively break through the time-frequency resolution restriction in comparison with the conventional short-time Fourier transform (STFT). Finally, the reconstruction of high-resolution ISAR image for a maneuvering target can be obtained in the RID domain. The effectiveness of the proposed ISAR imaging algorithm is validated by both simulated and real-measured SAR/ISAR data processing results.