Post-processing correction of frequency sweep nonlinearity for FMCW LiDAR based on GPST-SST

Frequency-modulated continuous wave (FMCW) LiDAR features high resolution and strong anti-interference ability, yet its performance is limited by the laser frequency sweep nonlinearity. In this paper, a nonlinear correction method based on time-frequency analysis is proposed, which combines the generalized parametric Stockwell transform (GPST) with the synchrosqueezing transform (SST) and applies phase compensation to the beat signal. For 100 repeated ranging experiments on a fixed target at 1 m, the standard deviation of the measurement error is only 0.3 mm. This study provides an effective technical solution for improving the measurement performance of FMCW LiDAR.