Relation Of Infrared Doppler Lidar To Remote Wind Measurements In The Turbulent Atmosphere

The performance of a coherent Doppler lidar is affected by the atmosphere. Refractive index inhomogeneities limit the effective aperture of our system to 15.5 cm + or - 4% on the average for a 2.6 km horizontal path 2 m above the surface under daytime conditions. Effective aperture scales as range to the -3/5 power. A differential Doppler technique can measure the wind vector in a single atmospheric volume with three (or mor) closely-spaced beams. This method works even when the distribution of velocities in the volume is wider than the velocity separation from beam angle differences. The structure function for backscatter and wind inhomogeneities scales approximately as r to the 2/3 power between the minimum detectable scale in our experiment and an outer scale of 100 to 500 m, depending on atmospheric condition. (Author).