The paper presents the measurement strategy and data set collected during the COTUR (COherence of TURbulence with lidars) campaign. This field experiment took place from February 2019 to April 2020 on the southwestern coast of Norway. The coherence quantifies the spatial correlation of eddies and is little known in the marine atmospheric boundary layer. The study was motivated by the need to better characterize the lateral coherence, which partly governs the dynamic wind load on multi-megawatt offshore wind turbines. During the COTUR campaign, the coherence was studied using land-based remote sensing technology. The instrument setup consisted of three long-range scanning Doppler wind lidars, one Doppler wind lidar profiler and one passive microwave radiometer. Both the WindScanner software and LidarPlanner software were used jointly to simultaneously orient the three scanner heads into the mean wind direction, which was provided by the lidar wind profiler. The radiometer instrument complemented these measurements by providing temperature and humidity profiles in the atmospheric boundary layer. The scanning beams were pointed slightly upwards to record turbulence characteristics both within and above the surface layer, providing further insight on the applicability of surface-layer scaling to model the turbulent wind load on offshore wind turbines. The preliminary results show limited variations of the lateral coherence with the scanning distance. A slight increase in the identified Davenport decay coefficient with the height is partly due to the limited pointing accuracy of the instruments. These results underline the importance of achieving pointing errors under 0.1^∘ to study properly the lateral coherence of turbulence at scanning distances of several kilometres.

中文翻译：

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COTUR 项目：用于风能应用的海上湍流遥感

本文介绍了在 COTUR（激光雷达的湍流一致性）活动期间收集的测量策略和数据集。该田间试验于 2019 年 2 月至 2020 年 4 月在挪威西南海岸进行。相干性量化了涡流的空间相关性，在海洋大气边界层中鲜为人知。该研究的动机是需要更好地表征横向相干性，横向相干性在一定程度上决定了多兆瓦海上风力涡轮机的动态风载荷。在 COTUR 活动期间，使用陆基遥感技术研究了相干性。仪器设置包括三台远程扫描多普勒风激光雷达、一台多普勒风激光雷达廓线仪和一台无源微波辐射计。WindScanner 软件和 LidarPlanner 软件共同用于将三个扫描头同时定向到平均风向，这是由激光雷达风廓线仪提供的。辐射计仪器通过提供大气边界层的温度和湿度分布来补充这些测量。扫描光束略微向上指向以记录表层内和表层上方的湍流特征，进一步了解表层缩放的适用性，以模拟海上风力涡轮机的湍流风载荷。初步结果显示横向相干性随扫描距离的变化有限。确定的 Davenport 衰减系数随高度略有增加，部分原因是仪器的指向精度有限。0.1 ^∘以正确研究几公里扫描距离处湍流的横向相干性。