Doppler-Shift Measurement with Fizeau Fringe Imaging Technique

As Fizeau interferometer(FI) produces linear fringes which can be conveniently detected by a linear detector, the direct detection Doppler lidar based on Fizeau fringe technique may prior to that based on Fabry-Perot fringe technique. The principle of Fizeau fringe technique and the retrieved method for Doppler frequency are discussed elaborately. In order to further study the Fizeau fringe imaging technique, an experimental system based on FI and linear detector has been set up, and the parameters of FI are optimized for practical wind lidar system. The correction method for Doppler frequency retrieval error by using Gaussian correlation algorithm is proposed. The measurement results show that the correction method can effectively improve the Doppler frequency retrieval accuracy, and after correcting, the standard deviation of Doppler frequency measurements is 4.8 MHz in the very large dynamic range of -645 MHz~ 645 MHz, which is equivalent to 3.9% of the detector resolution.