An analytical model for wind velocity uncertainty estimations in ground-based Doppler lidar measurements

This article presents an analytical model to estimate wind velocity uncertainties in ground-based (dual) Doppler lidar measurements. The model follows the principles of uncertainty propagation as recommended by the Guide to the Expression of Uncertainty in Measurements. Key-input quantities of the measuring model considered uncertain include elevation and azimuth angles and focus distance, or range. The uncertainty model also accounts for bias and random errors originating from hardware components and data processing techniques. Uncertainty correlations within a single lidar and between instruments in a dual-lidar system are addressed. The measurement model assumes perfect spatio-temporal synchronisation between the lidar instruments while probing a non-turbulent wind inflow described by a vertical shear model. Results from the analytical solution are verified using Monte Carlo simulations, obtaining very good agreement from the comparison. The pattern of the uncertainty distributions is predominantly influenced by the relative positioning of the measuring system(s) and the intended measurement point(s). The magnitude of the uncertainty distributions is principally determined by the intrinsic uncertainty of the lidar, modulated by the set of relevant uncertainty correlations.