Analysis of errors induced by angle tuning in direct detection Doppler wind lidar

The wind measurement accuracy was influenced by the errors of angle tuning in direct detection Doppler wind lidar. Aiming at the errors of angle tuning, theoretically, we deduced the expression between the transmission of F-P etalon and the incident angle and divergence of laser, by which the errors induced by the incident angle, divergence, line-width and stepping angle were analyzed. In the direct detection Doppler wind lidar system using aerosol scattering, simulation results show that when the system resolution is 2 × 10⁶, the diameter of F-P etalon should be larger than 8 cm; in the region of approximate normal incidence, with the divergence below 150 μrad, the peak of transmission spectrum shifts 1 MHz when the incident angle is altered for 10 μrad, it means that the measured error is 0.5 m/s for a wavelength of 1064 nm.