提出了基于光纤折叠结构的分布式温度传感器系统,该系统只采用反斯托克斯散射光的方法解调温度.由于光纤折叠结构的应用,光纤内相对于半长度处对称的两个不同位置的后向拉曼散射所携带的温度场信息相同,这样就可以只探测反斯托克斯散射光强解调出温度,从而消除了传统方法中由于波长不同而引起的损耗差,有效提高了测量精度.最后用时域累加平均预处理信号,再用小波变换使信噪比由1 dB提升到11 dB.%A new distributed temperature sensor system based on fiber-folded structure was proposed.The sensor system demodulated the temperature by using anti-Stokes scattering only.Due to the application of folded fiber structure,the temperature field information sensed by Raman backscattering was the same at the symmetrical location to the half lengths of the fiber.The temperature could be demodulated by detecting the anti-Stokes backscattering intensity only.The differential attenuation in the traditional method was eliminated between anti-Stokes and Stokes signal and the accuracy of measurement was improved effectively.Finally,cumulative average in time domain and wavelet transform were applied,and the SNR was promoted from 1 dB to 11 dB.
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