Comparison and Verification of Coherent Doppler Wind Lidar and Radiosonde Data in the Beijing Urban Area

Abstract

As a new type of wind field detection equipment, coherent Doppler wind lidar (CDWL) still needs more relevant observation experiments to compare and verify whether it can achieve the accuracy and precision of traditional observation equipment in urban areas. In this experiment, a self-developed CDWL provided four months of observations in the southern Beijing area. After the data acquisition time and height match, the wind profile data obtained based on a Doppler beam swinging (DBS) five-beam inversion algorithm were compared with radiosonde data released from the same location. The standard deviation (SD) of wind speed is 0.8 m s⁻¹, and the coefficient of determination R² is 0.95. The SD of the wind direction is 17.7° with an R² of 0.96. Below the height of the roughness sublayer (about 400 m), the error in wind speed and wind direction is significantly greater than the error above the height of the boundary layer (about 1500 m). For the case of wind speeds less than 4 m s⁻¹, the error of wind direction is more significant and is affected by the distribution of surrounding buildings. Averaging at different height levels using suitable time windows can effectively reduce the effects of turbulence and thus reduce the error caused by the different measurement methods of the two devices.