Analysis of the measurement uncertainty for a 3D wind lidar

High-resolution three-dimensional (3D) wind velocity measurements are of major importance for the characterization of atmospheric turbulence. The use of a multi-beam wind lidar focusing on a measurement volume from different directions is a promising approach for obtaining such wind data. This paper provides a detailed study of the propagation of measurement uncertainty of a three-beam wind lidar designed for mounting on airborne platforms with geometrical constraints that lead to increased measurement uncertainties of the wind components transverse to the main axis of the system. The uncertainty analysis is based on synthetic wind data generated by an Ornstein-Uhlenbeck process as well as on experimental wind data from airborne and ground-based 3D ultrasonic anemometers. For typical atmospheric conditions, we show that the measurement uncertainty of the transverse components can be reduced by about 30 %-50 % by applying an appropriate post-processing algorithm. Optimized post-processing parameters can be determined in an actual experiment by characterizing measured data in terms of variance and correlation time of wind fluctuations, allowing for the optimized design of a multi-beam wind lidar with strong geometrical limitations.