Low-Altitude Wind Measurement Using Incoherent Doppler Lidar by Utilizing Both Absorption Slopes of the Iodine Absorption Spectrum

Abstract

In this study, we perform wind observation in the lower troposphere using the incoherent Doppler wind lidar that we previously developed for the upper troposphere and stratosphere. This Doppler lidar uses both slopes of the iodine absorption spectrum, and the Doppler shift is obtained from the ratio of the two transmission signals. Because this ratio is influenced by Mie contamination, a precise Mie measurement improves the quality of wind observation in the Mie contamination region. If the iodine absorption spectrum completely absorbs the Mie signal, wind measurement will be independent of Mie contamination. The effect of Mie contamination on wind measurement by Mie-Rayleigh backscattering is quantified and the need for the absorption of the Mie signal is assessed. Moreover, we compare the wind profiles measured in the Mie contamination region using the Doppler wind lidar and a wind profiler. The average wind difference between the lidar and the wind profiler is 1.39 m/s. The Mie contamination was completely excluded by the iodine absorption spectrum and lidar comparison experiment demonstrated the high feasibility and good capability of the lidar for measuring wind in the Mie contamination range.