Comparison of turbulence spectra derived from LiDAR and sonic measurements at the offshore platform FINO1

Traditional meteorological masts, that are usually used for instance to perform a wind power curve measurement or wind resource evaluations, are very expensive to install in offshore locations. Therefore, we have to search for an alternative method to replace the standard wind measurements (from cup or sonic anemometers) used on a mast. The LiDAR technique is becoming in the last years a promising substitute with the advantage that higher vertical measurements over the whole rotor diameter can be performed (e.g. [1] [2] ,[3] ). However, before taking LiDAR as an overall accepted wind measurement alternative we have to understand and validate how this technique derives both mean and turbulent wind speed parameters. In the present work, wind measurements given by an up-ward pointing ground-based wind LIDAR (= VAD mode (velocity azimuth display mode) are analyzed and compared with in-situ mast measurements at the research offshore platform FINO1 in the North Sea. The comparison of the 10-min wind values shows a good reliability of the LiDAR in offshore conditions [4] . However, it is not verified sufficiently until now, how the LIDAR technique is performing on the higher frequencies. To this aim, results based on a spectrum study are presented.