The Doppler Lidar system measures the upper-air wind field by emitting a laser beam into the sky and receiving the light backscattered by aerosols (dust and fine particles in the atmosphere that cannot be seen by the eye). The wind speed and direction are calculated from the Doppler frequency shift of the scattered light due to the aerosol movement.
Under a typical daytime atmospheric condition, the Doppler Lidar StreamLine unit can measure wind direction and wind speed up to an elevation of 1000m at a time resolution of 1–30 seconds and at a spatial resolution of 10m or less. It was confirmed to produce very precise measurement data in a comparison test with a certified cup anemometer by the Technical University of Denmark.
Due to the high directivity of the laser beam, measurement is possible as long as the field of view in the target direction is unobstructed. Vertical profiling of the horizontal wind will be possible if the sky is clear of obstructions within approximately 30 degrees around the zenith.
As the laser beam is eye-safe and produces hardly any noise, it will not pose any human hazard or adversely affect the surrounding environment.
Contributing to Aviation Safety
Doppler lidar StreamLine enables the visualisation of various types of turbulence that can affect aviation safety.
An example of such is wingtip vortices, which are trails of air that form from each wingtip and remain in the air after the passage of the aircraft.
Another type of turbulence, one that affects flight operations in mountainous areas, is mountain waves. Mountain waves are the oscillations that form down wind of a mountain when air currents are forced upwards by the mountain.
StreamLine is used to ascertain and monitor such meteorological phenomena. In this way, it is contributing to today’s aviation safety.