A Frequency Nonlinearity and Fluctuation Correction Method for Terahertz ISAR Imaging

摘要

Due to the high frequency band and wide bandwidth of Terahertz imaging radar, the high frequency generally performs unstable in system. In detail, the linearly frequency modulated (LFM) signal shows nonlinearity and the frequency center fluctuates randomly with time. It will potentially lead to the degradation of Terahertz inverse synthetic aperture radar (THz-ISAR) imaging quality. To address this problem, this paper presents a frequency nonlinearity and fluctuation correction method based on minimum entropy (ME). Following the error model, both the error can be corrected by applying the ME metric to the range and azimuth direction. The feasibility and adaptability of this proposal have been validated by simulation and real data experimental result.