Research on signal acquisition and processing of lidar wind measurement system

In order to meet the requirements of wind speed measurement in wind field, a high-speed signal acquisition and processing module of lidar wind measurement system based on FPGA has been developed, which was responsible for lidar echo signal acquisition, Fast Fourier Transform (FFT) and spectrum data accumulation and averaging operation. The collected 1 024 point echo data was calculated by flow mode and block floating-point structure FFT to obtain single spectrum data and 1 024 cumulative average spectrum data respectively, and the data transmission module was reliably transmitted to the host computer for display and analysis. By building a continuous coherent lidar wind measurement system with the working wavelength of 1 550 nm, the index of the signal acquisition and processing module was tested and the cumulative average filtering algorithm was verified. The experiment results show that the acquisition and processing module can meet the real-time acquisition and processing of echo signal under the 100 MHz clock, and the spectrum resolution reaches 97.66 kHz, and the accuracy of wind speed measurement is improved to 7.57 cm/s.