The COTUR campaign at Obrestad, January-December 2019

COTUR (Measuring COherence and TURbulence with lidars) is a joint reserach project under the lead of NORCE (former CMR) with the Geophysical Institute of the University of Bergen, the University of Stavanger, and Equinor as partners.

One of the WindCube 100S on top of its measurement rack in front of Obrestad lighthouse. (Photo: Pablo Saavedra, UiB)

Main goal is the investigation of coherence in the turbulent wind field at scales that are relevant for state-of-the-art offshore wind turbines, with rotor diameters of beyond 150 m (GE recently announced their new Haliade-X 12 MW machine with a rotor diameter of ca. 220 m).

Measurement setup of the three scanning lidar systems at Obrestad Lighthouse

Core of the campaign is the deployment of three scanning lidar systems (Leosphere WindCube 100S) in a triangular setup. The lidars will mainly be operated in stirring mode with parallel or slightly diverging beams into the main wind direction, to allow for the analysis of coherence in the offshore wind field based on different separation distances. A static lidar wind profiler (Leosphere WindCube v1) will continuously provide wind speed and wind direction information up to 300 m above ground, that will also be used to modify the measurement direction of the three scanning lidar systems for the coherence investigations. Temperature and humidity profiles in the lowest 3 km of the atmosphere are measured by a passive microwave radiometer (Radiometer Physics HATPRO RG4).