Dongsong SUN^1,2, Zhiqing ZHONG², Jun ZHOU², Huanling HU² and Takao KOBAYASHI³

¹Beihang University, Beijing 100083, P. R. China
²Anhui Institute of Optics and Fine Mechanics, Hefei 230031, P. R. China
³Fukui University, Fukui, Japan

(Received January 17, 2005; Accepted July 15, 2005)

A direct detection Doppler wind lidar with the dual Fabry–Perot technique has been built in Hefei, China, and the system is described in this paper. A dual, air-spaced Fabry–Perot etalon is designed as the frequency discriminator and the transmission characteristics are measured with a stabilized cw laser and a pulse laser. The experimental data are found to be in agreement with the designed parameters. The Doppler shift is measured by taking the ratio of the transmitted intensities from the dual etalon. Analysis of the accuracy of Doppler measurement is made by considering the factors of the number of iterations in converting the measured ratio to the Doppler shift, the laser intensity fluctuation and the signal-to-noise ratio. In the sufficient signal-to-noise ratio the velocity accuracy of the Doppler lidar system is estimated to be better than 0.5 m/s.

Key words: lidar, wind, Fabry–Perot etalon, aerosol, direct detection