Assessing the potential of a commercial pulsed lidar for wind characterisation at a bridge site

Characterisation of atmospheric turbulence is a central step prior to the construction of long-span bridges. The present paper investigates the potential of a long-range scanning pulsed coherent lidar to measure the wind field at the inlet of a fjord. The wind velocity data acquired by the lidar is compared to the data recorded by sonic anemometers installed on the bridge. The focus is on the ability of the lidar to capture single and two-point statistics of turbulence in complex terrains. Satisfying results are obtained with the Line-of-Sight scanning mode, which provides the best sampling frequency (1 Hz). The low temporal resolution and the low signal-to-noise ratio for the Range Height Indicator and the Plan Position Indicator scanning modes are important limiting factors in the pilot study performed. Better results may be achieved for a lidar measurement set-up which is adapted specifically for investigating coherence.