Impact of Phase Error on Coherent LiDAR: Analysis and Validation

Phase error is one of the main causes of performance degradation in coherent LiDAR system. The impact of phase error is commonly quantified using the signal-to-noise ratio based on additive white Gaussian noise (AWGN) model, whereas this oversimplification disregards frequency-dependent information and fails to describe the real behavior of phase error in practical applications. In this paper, a comprehensive and concise model is derived and validated through simulations and experiments, which can accurately describe the influence of phase error on coherent LiDAR measurement. Utilizing this model, we conclude that phase-modulated continuous wave (PMCW) signal exhibits superior phase error resistance compared to commonly used frequency-modulated signals. Consequently, we achieved PMCW based synthetic aperture LiDAR (SAL) imaging at a distance of 22.5 km, which is the farthest distance according to our knowledge.