NASA Dryden Flight Research Center says that recent flight testing of a device designed to detect clear-air turbulence may lead to its installation on commercial aircraft. This follows a spate of incidents which have resulted in injuries to passengers.
The sensor relies on a laser radar (a Lidar) which detects changing velocities of particles in turbulent air. This concept uses an infrared light pulse transmitted from the laser, some of which is reflected off the particles and back to the sensor.
The reflected light has a slight Doppler shift in frequency caused by aircraft motion relative to the particles. By analysing the shift, changes in wind velocity along the beam's path can be determined.
The experiment, called the Airborne Coherent Lidar Advanced In-flight Measurement, was conducted from a Lockheed Electra research aircraft flying over the Rocky Mountains in Colorado. Additional flights are scheduled to add to the turbulence database and to fine tune the sensor.
Source: Flight International