# Coastal Wind Measurements Using a Single Scanning LiDAR
## 5 Conclusions
We first confirmed that the CNR value was closely associated with the accuracy of the measurements by making comparisons with the vertical profiling LiDAR observations. The additional analysis for Case 8 showed that we can expect a data availability level of \(85\%\), \(80\%\), and \(70\%\) at distances of 2000, 2500, and 3000 m, respectively, if we employ a CNR value of \(-30\) dB as the threshold for the data reliability index. We also confirmed that the determination coefficient was connected with the measurement accuracy. The determination coefficient obtained via the curve fitting process in the VVP method was an additional indicator for assessing the data quality. Finally, we also examined the measurement accuracy of TI by comparing the scanning LiDAR-based measurements with the SA measurements near the surface in Case 9. We found that the differences between the standard deviations of the SA and 100s wind speeds were much larger than the differences between the 10-minute mean wind speeds and directions. Due to the coarse temporal resolution and large measurement volume of the 100s, the 10-minute standard deviations from the 100s were expected to be more scattered than those from the SA. In addition, the 90% quantiles of the standard deviations for the SA and 100s measurements were compared. As a result, the difference in the TI was less than the difference between the IEC standard categories. Thus, we found that using a single scanning LiDAR for offshore wind measurements had potential not only for wind resource assessment but also for assessing the site-specific conditions considered in wind turbine design. Overall, the offshore wind measurements using a single scanning LiDAR with the VVP method showed good performance when compared to the reference observations obtained at a distance of 400 m from the scanning LiDAR. An attempt to evaluate the data availability further offshore showed that this measurement method would be equally as accurate within a range from 2000 to 2500 m. Accordingly, we argue that using a single scanning LiDAR with the VVP offers a promising and cheaper alternative to in situ observations using offshore meteorological masts and floating LiDAR technologies. For future research, we plan to conduct measurement campaigns with an offshore met mast and a vertical profiling LiDAR located 2 to 3 km away from the two scanning LiDARs installed on the coast to compare the performance with dual LiDAR measurements. Conceptualization, S.S. and J.P.G. ; Data curation, S.S., J.P.G., T.O., T.K. and S.N. ; Funding acquisition, S.S. and T.K. ; Methodology, S.S. and J.P.G. ; Project administration, S.S.; Writing--original draft, S.S. and J.P.G. ; Writing--review and editing, T.O., T.K. and S.N. All authors have read and agreed to the published version of the manuscript. This work was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Number 17H03492. This research was also supported by an international collaboration project for energy technologies funded by the Japanese Ministry of Economy, Trade and Industry (METI). The authors declare no conflict of interest.