分布式光纤传感数据采集系统设计

Design of data acquisition system for distributed optical fiber sensor

基于拉曼散射温度效应和光时域反射技术,设计了100 MHz高速数据采集系统SDLaser_DAQ600,实现对空间环境温度场测量。在数据采集系统中利用现场可编程逻辑门阵列(FPGA),采用实时累加平均算法对原始光纤传感信号进行累加平均,支持10 km光纤实时采样,空间分辨率达到1 m。实验结果表明,65 536次数据累加平均可以得到平滑的斯托克斯和反斯托克斯曲线,使光纤传感信号的信噪比提高到90 d B以上,能够为分布式温度测量提供良好的数据支持。

Based on the Raman scattering temperature effect and the optical time domain reflection technology, a 100 MHz high-speed data acquisition system SDLaser_ DAQ600 was developed to measure the temperature field of space environment. In the data acquisition system, using real time averaging algorithm in the FPGA, DAQ600 has realized 65 536 times cumulative averaging for original fiber sensor signals, which supported real-time sampling of 10 km length fiber with 1m spatial resolution.The experimental results show that, signal-to-noise ratio for optical fiber sensing can be increased to more than 90 dB through the 65 536 times cumulative averaging. Finally, smooth curves of Stokes and anti-Stokes have been obtained, which could provide proper data support for distributed temperature system measurement.