Validation of near-shore wind measurements using a dual scanning light detection and ranging system

Abstract

This paper reports results from a 2-month validation campaign of near-shore wind measurements taken by a dual scanning light detection and ranging (LiDAR) system at a coastal site in Japan. A meteorological mast and a vertical profiling LiDAR device were deployed at an offshore research station approximately 1.5 km from the coast. Offshore winds at heights of 66, 120, and 180 m above sea level were observed by the scanning LiDAR system. Comparisons with a sonic anemometer found that the radial velocities had a coefficient of determination of more than 0.99 without unreasonable bias. The accuracy of 10-min mean wind speeds and directions was then evaluated. The 10-min values from the dual scanning LiDAR system were accurate enough to satisfy the acceptance criteria used for floating LiDAR systems. In addition, the vertical velocity and direction profiles from the dual scanning LiDAR system were compared with those from a vertical profiling LiDAR device. The performance of turbulence intensity (TI) measurements was also evaluated. Although the TIs from the dual scanning LiDAR system were slightly lower than those from the sonic anemometer, they were equivalent to those from the cup anemometers. This investigation concluded that the near-shore wind measurements using the dual scanning LiDAR system are beneficial for reducing near-shore wind measurement costs, because the system can measure not only 10-min wind speed and direction, but also parameters associated with assessing site-specific conditions without installing offshore meteorological masts.