This paper presents a novel measurement technique for long-term, high-temporal resolution wind velocity observations in offshore wind farms, while also addressing the need for spatial coverage. The approach involves the deployment of a ship-based lidar system consisting of two co-located lidars on a vessel. This strategy is designed to enable a detailed assessment of vertical wind velocity within and around offshore wind farms.

We present a new structure function model to estimate the turbulence energy dissipation rate using lidar velocities. The model corrects for turbulence filtering due to the lidar probe volume by applying a Gaussian weighting function. By utilizing the high 3 m range-gate resolution of the BEAM 6x pulsed lidar, we achieve excellent agreement between turbulence energy dissipation rate values derived from lidar and sonic anemometer at three heights, with correlation coefficients exceeding 0.9.

A simple adaptive variant of the Doppler Beam Swinging (DBS) method is presented to improve the availability of wind velocity measurements in profiling lidars, particularly at higher altitudes. Following validation at the Østerild test site in Denmark, using three profiling lidars compared with cup anemometers and wind vanes, excellent agreement was observed. Availability assessments indicated a maximum increase of 16.9 percentage points over the standard approach.

This research investigates a novel method for directly estimating wind velocity variances from averaged Doppler spectra in the frequency domain. Compared to the conventional time-domain approach, the proposed method offers a substantial improvement. Despite some limitations, this study marks a significant advancement in turbulence estimation using pulsed Doppler lidars, which presents promising potential for wind turbine load assessments.

Dual-lidar measurements are explored here as a cost-effective alternative for measuring the wind at great heights. From measurements at a mountainous site, we showed that this methodology can accurately capture mean wind speeds and turbulence under different flow conditions, and we recommended optimal lidar placement and sampling rates. This methodology allows the construction of vertical wind profiles up to 430 m, surpassing traditional meteorological mast heights and single-lidar capabilities.