LiDAR by Jim Roby

LIDAR is similar to a radar but sends out a packet of light at a specific wave length. In the case of a wind finding LIDAR, the wavelength is 1.5 to 2.0 microns which is a very short. A certain portion of the light is reflected back to a special "telescope" which is sensitive to the wavelength of the emitted light. i.e 1.5 to 2.0 micons. If the emitted light encounters any object, (in wind finding the objects are small particles of naturally occurring aerosols,) the time and magnitude of the reflected light is received via the telescope by very special detectors. After the return signal is processed, the results can be the velocity of the aerosols which is also the velocity of the wind moving either away from or toward the telescope. Using time, we then know the distance of the computed wind vector. Thus we have a Doppler LIDAR that in concept is exactly like the RADAR. If the light is emitted via a two axis scanner, we can measure the wind velocity and direction surrounding the LIDAR.

By Jim Roby