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Design and Implementation of Signal Acquisition System for Laser Doppler Velocimeter

To meet the requirements of signal collection in multidimensional laser Doppler velocimeter (LDV), a multichannel signal acquisition system is designed based on DSP and FPGA technologies. In addition, in order to extract the frequencies of signals in multidimensional LDV system, fast Fourier transform approach combined with energy centrobaric rectifying algorithm are applied. The structure and realization of multichannel signal acquisition system are detailedly introduced. The FPGA technology is been used for high-speed signal gathering while the DSP technology is used for real-time signal processing. Besides the algorithm of Doppler frequency extraction is explained. The experiment results of signal detection indicate the design in this work can realize the high-speed acquisition of three-channel signals in LDV system and achieve high precision in the extraction of Doppler frequency.