A Novel Range Profile Compensation Method of High Speed Target for ISAR

摘要

High Speed Motion of target will lead to the peak splitting and spectrum spreading of the range profile, which does harm to the traditional R-D imaging algorithm. Due to the low processing bandwidth, the previous high speed compensation methods are mostly based on the Stretch system, where the echo signals are modeled as multi-component LFM signals, and motion compensation is achieved by estimating the chirp rate. However, these methods cannot be directly applied to the matched filtering system, so the coherence of the echoes cannot be utilized. For this, a range profile compensation algorithm of high speed target for ISAR based on wideband Radon-Fourier transform (WRFT) is proposed. The response function of the wideband matched filter is firstly given, and at second the motion of the target is projected to the range-velocity plane by WRFT, so as to realize the coherent accumulation of signal energy. At last, with the accurate estimated velocity of the target, a compensation function is constructed to eliminate the range walk. Furthermore, a compensation method based on wideband generalized Radon-Fourier transform (WGRFT) for high speed high maneuvering is deduced. Simulation results show the effectiveness of the range profile compensation algorithms.