Lidar measurements of temperature turbulence in the atmosphere

摘要

Optical turbulence is an important characteristic for laser propagation in the atmosphere. The optical turbulence causes refractive index fluctuations in the air. The accumulative atmospheric refractive index fluctuations can incur deleterious effects to a laser beam propagating in the atmosphere by distorting its wavefront. Accurate characterization of turbulence in the atmosphere is important to many light propagation studies and related applications. Temperature fluctuations/turbulences in the atmosphere are highly correlated with the atmospheric optical turbulence. In many occasions, optical turbulences profiles in the atmosphere were obtained through the measurements of temperature turbulence and other other atmospheric quantities, for example, air humidity. Therefore determination of temperature fluctuations/turbulences parameter C_T~2 is helpful to the measurement of optical turbulence. Thermosonde was commonly seen in measurements of C_T~2 in the past. Here we show that a direct lidar system is able to fulfillrnthe task of C_T~2 measurements. And compared to the thermosonde measurements the proposed lidar method has many advantages.