Tests validate new Lidar software

Lidar outfit Leosphere has validated a next-generation wind modelling system that sharpens measurement data on project sites with complex terrain.

Tests of a Windcube V2 Lidar oufitted with its new flow complexity recognition (FCR) software, carried out by Danish R&D centre DTU at ERS' 48MW Hrgud wind farm in Bosnia & Herzegovina, showed the upgraded unit trimmed the measurement bias from -4.1% to +1.5% compared to the cup anemometer met mast.

"Traditional Lidars weren't able to measure the wind speed in complex terrain with sufficient accuracy because the wind speed is not horizontally homogeneous," says Leosphere chief executive Alexandre Sauvage.

"The FCR technology is essentially an on-line correction system [with a] unique fifth vertical beam [that] accounts for the impact of the terrain complexity on the measurements. The FCR upgrade enables our Windcube V2 Lidar to reach a measurement difference of only 1.5% compared to met mast-based measurements."

The field tests at Hrgud, a turbulent and complex wind site, on an oblong 100-metre-high hill about 1.5km north of a 1,000-metre-deep and 2,000-metre-wide canyon, checked the new systems against a 77.5-metre reference met mast set up by consultancy COWI as part of a larger feasibility study.

"Until now, in both complex terrain and complex flow situations, all remote sensors on the market have shown a measurement bias due to the lack of flow homogeneity across the measured volume. With our FCR option, we offer a product that significantly reduces this bias," says Sauvage.