Patent ID: 8733164

Claim:
A wind turbine optical wind sensor apparatus, comprising: a first light source arranged to emit multiple beams of light as a first sensor beam, the first sensor beam comprising two or more individual beams of light, wherein each individual beam of light has a different frequency characteristic in comparison to at least one other individual beam of light in the sensor beam; at least a second light source arranged to emit multiple beams of light as at least a second sensor beam, the multiple beams in the at least a second sensor beam light comprising two or more individual beams of light, wherein each individual beam of light has a different frequency characteristic in comparison to at least one other individual beam of light in the at least a second sensor beam; wherein the first sensor beam and the at least a second sensor beam are arranged such that they are at least partly orthogonal to each other and point in different directions at least with reference to a two dimensional detection plane; a first light receiving device coupled to an optical sensor for detecting flashes of light, caused as matter carried in the wind passes through the multiple beams of light; a first focussing device for focussing the individual beams of light in the first sensor beam at respective focal points in the vicinity of the first light receiving device, such that the focal points of the individual beams are adjacent one another; at least a second focussing device for focussing the individual beams of light in the at least a second sensor beam at respective focal points in the vicinity of the first or at least a second light receiving device, such that the focal points of the individual beams are adjacent one another; and a controller, coupled to the optical sensor, for processing the flashes of light detected by the optical sensor as matter carried in the wind passes through the first and the at least a second sensor beam, and based on the flashes of both the first and at least the second sensor beam determining both the speed and direction of motion of the matter and the wind in the two dimensional detection plane.