Enhancing turbulent fluctuation measurement with tailored wind lidar profilers

This study separately investigates the impact of an enhanced sampling rate and reduced probe length on turbulent measurements using the Vaisala WindCube v2.1 lidar profiler, in comparison to the commercially configured WindCube v2.1. In the first experiment, a tailored lidar sampled four times faster than the standard setup. In the second experiment, a tailored lidar employed a 15 m probe length, compared to the commercial configuration’s 23 m. The study offers a detailed analysis of how these changes affect various aspects of wind measurement, including mean wind speed, standard deviation, velocity spectra, noise level, integral length scale, and dissipation rate. Increasing the sampling rate improves turbulence measurement without affecting mean wind speed measurement. However, a slight reduction in data availability was observed compared to the commercial configuration. Reducing the probe length results in higher standard deviation values compared to the commercial configuration, but this comes at the expense of increased noise levels, making it unclear whether the higher standard deviations are due to the energy of smaller eddies or noise. Additionally, the reduced probe length configuration exhibited a high bias in mean wind speed measurement and had a limited impact on other turbulence metrics. These findings suggest that the best improvement for turbulence measurement with the WindCube lidar profiler is achieved through an increased sampling rate.