Design and experimental verification of a novel Mie Doppler wind lidar based on all-fiber Mach-Zehnder frequency discriminator

Abstract

Spaceborne Doppler wind lidar is currently one of the hot spots on the lidar technology. The all-fiber Mach-Zehnder interferometer (FMZI) as a frequency discriminator of Doppler wind lidar is proposed for profiling the atmospheric wind velocity. The frequency discriminator system parameters are optimized, and the retrieval method of wind velocity based on FMZI is deduced. The arm length difference of FMZI for the aerosol backscattering signal is optimized to be 74.8cm at the laser wavelength of 532nm. The maximum system sensitivity for wind profiling can reach up to 2.62%/(m/s), and the dynamic range of wind velocity is ±18.2m/s. The system simulation shows that the detection range is up to 6.7km for 1m/s wind velocity error at a wind velocity of 15m/s with laser energy of 250mJ and telescope diameter of 406mm. A rotating disc experimental system is designed to simulate the atmospheric wind field for verifying the feasibility of the system, and the results show that there is good agreement between the retrieved wind velocity and simulated wind velocity. The simulation and experimental test results show that FMZI is feasible as a frequency discriminator and can be suitable for direct Mie Doppler lidar, especially for satellite-based platform lidar due to its desirable characteristics, including its small volume, light weight, good stability and compact structure.