Abstract：
Frequency sweeping interferometry (FSI) based absolute distance ranging has high precision and no ranging blind area. It can be used to realize large-scale and non-cooperative target measurement. However, the nonlinear frequency modulation of the laser seriously affects the ranging accuracy. In this manuscript, a measurement method assisted by Hilbert Transform (HT) and Chirp-z Transform (CZT) is proposed, which can realize the phase unwrapping of the beat signal, the length reduction in the delay fiber of auxiliary optical path, and the improvement of the frequency resolution. The narrow-band frequency suitable for HT is further studied. In the experiment, the ranging resolution is 70 μm and the standard deviation is 12.6 μm within a distance of 4005 mm.
摘要：
基于频率扫描干涉测量(FSI)的绝对距离测距具有高精度和无测距盲区。可用于实现大规模非合作目标测量。然而,激光器的非线性调频严重影响测距精度。在这份手稿中,提出了一种希尔伯特变换(HT)和Chirp-z变换(CZT)辅助的测量方法,可以实现拍频信号的相位展开，辅助光路延迟光纤的长度减少，频率分辨率的提高。进一步研究了适合HT的窄带频率。在实验中,在4005mm的距离内，测距分辨率为70μm，标准偏差为12.6μm。
