Two-beam lidar measurements in a non-homogeneous wind field

Nacelle based wind lidars are designed to sit atop a wind turbine structure and make measurements at given distances from it. Most times the lidar faces the turbine’s upstream direction to sense oncoming wind. Two lidars were set up looking upstream on two adjacent offshore turbines in Denmark. The case considered was for when the turbines were oriented such that one lidar was looking into the free stream while the other lidar had one beam in the first turbine’s wake and the other beam in near free stream conditions. This enabled the possibility to look at horizontal wind speeds reconstructed inside homogeneous and non-homogeneous wind fields. Data for the two lidars were processed and averaged over different intervals. Correlations of radial and horizontal wind speeds in different wind fields were performed. Results in this case show horizontal wind speeds reconstructed in non-homogeneous field similar to those reconstructed in a (assumed) homogeneous one.