Theoretical Precision Limits of LiDAR in Turbulent Channels

Atmospheric turbulence channels represent a critical factor that must be considered when developing free-space laser applications. While extensive research has been conducted on optical wireless communication (OWC) in turbulent conditions, investigations into light detection and ranging (LiDAR) in turbulent channels remain relatively unexplored. In this letter, theoretical modeling and derivations are developed to characterize the ranging and velocity precision of LiDAR in turbulent channels. The derived Cramér-Rao lower bounds (CRLBs) in Gamma-Gamma channels are verified by Monte Carlo simulation. The CRLBs reveal that, under identical signal-to-noise ratio (SNR) conditions, the precision values at a Rytov variance of 0.3 and 0.6 are 1.56 and 2.37 times those at a Rytov variance of zero for the time-of-flight (ToF) LiDAR, respectively. In the frequency-modulated continuous wave (FMCW) LiDAR system, the corresponding precision value ratios are 1.15 and 1.29. These findings enable rigorous performance evaluation and optimized design of LiDAR systems operating in turbulent environments.