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