Key focusing optics supplied to new low-cost fibre lidar system, for making local wind speed measurements in front of wind turbines
Optical Surfaces has supplied the key focusing optics for a new low-cost fibre lidar system recently launched by Qinetiq for making local wind speed measurements in front of wind turbines. Qinetiq has been a pioneer in the development and implementation of Lidar systems for wind sensing for over 20 years.
Its new fibre lidar anemometer provides remote wind speed and direction measurements up to 200m distant.
Apart from many meteorological and air traffic control applications, the lidar offers a unique advantage to the wind energy industry by providing warning of turbulence and wind speed changes that will permit intelligent blade pitch control.
Optical Surfaces was selected by Qinetiq to produce a lens design that would provide a focus at 200 metres that was diffraction-limited, so as to give the ultimate in performance.
The use of an aspheric surface allowed the designer to achieve the reqired performance with the fewest components - reducing the build cost of the system.
The lens design created comprised a 200mm focal length aspheric doublet with a durable V-coat to optimise performance at 1.5um, but also to allow the lens to be cleaned.
The aspheric doublet was supplied mounted and tested after coating by topographic and interferometric analysis. Operating at a wavelength of 1.5um, the fibre lidar is inherently eye-safe and may be installed, operated and maintained without the need for special precautions.
