There is an optical interference noise in the conventional Raman-based fiber-optics distributed sensing, which results in a poor temperature resolution performance. In addition, the traditional whole-fiber demodulation principle complicates the operation steps of the system. In this paper, a novel dynamic difference attenuation recognition (DDAR) principle is operated in the DDP scheme (dual demodulation principle) and the SDP scheme (self-demodulation principle) respectively. It not only helps to eliminate the optical interference noise, but also omits the whole-fiber calibration process. In this experiment, a temperature resolution of 0.30 °C (17.0 km) is achieved through using the DDP scheme based on the DDAR principle, and the measurement time can be shortened to 1.5 s. Meanwhile, a temperature resolution of 0.18 °C (17.0 km) is obtained for the SDP scheme under the DDAR principle. The SNR of DDP and DSP schemes can be optimized to 12.82 dB and 13.32 dB by the proposed DDAR technology. Furthermore, the temperature resolution performance under a large temperature measurement range (0–1000 °C) is theoretically analyzed. The results indicate that the temperature responsivity for DDP and SDP schemes are parabolic and linear type respectively, which causes the temperature resolution of the two schemes to show a different trend with the change of temperature. The proposed DDAR method also can improve the temperature resolution in such a large temperature measurement range.

中文翻译：

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动态差异衰减识别的基于拉曼的光纤分布式传感器的温度分辨率提高

传统的基于拉曼的光纤分布式传感中存在光学干扰噪声，这导致较差的温度分辨率性能。另外，传统的全光纤解调原理使系统的操作步骤复杂化。本文分别在DDP方案（双重解调原理​​）和SDP方案（自解调原理）中运用了一种新颖的动态差分衰减识别（DDAR）原理。它不仅有助于消除光学干扰噪声，而且省略了整个光纤校准过程。在本实验中，通过使用基于DDAR原理的DDP方案，可以实现0.30°C（17.0 km）的温度分辨率，并且测量时间可以缩短至1.5 s。同时，温度分辨率为0.18°C（17。在DDAR原理下，对于SDP方案可获得0 km）。所提出的DDAR技术可以将DDP和DSP方案的SNR分别优化为12.82 dB和13.32 dB。此外，从理论上分析了在较大温度测量范围（0–1000°C）下的温度分辨率性能。结果表明，DDP和SDP方案的温度响应分别为抛物线型和线性型，这导致两种方案的温度分辨率随温度的变化而呈现不同的趋势。提出的DDAR方法还可以在如此大的温度测量范围内提高温度分辨率。理论上分析了在较大温度测量范围（0–1000°C）下的温度分辨率性能。结果表明，DDP和SDP方案的温度响应分别为抛物线型和线性型，这导致两种方案的温度分辨率随温度的变化而呈现不同的趋势。提出的DDAR方法还可以在如此大的温度测量范围内提高温度分辨率。理论上分析了在较大温度测量范围（0–1000°C）下的温度分辨率性能。结果表明，DDP和SDP方案的温度响应分别为抛物线型和线性型，这导致两种方案的温度分辨率随温度的变化而呈现不同的趋势。提出的DDAR方法还可以在如此大的温度测量范围内提高温度分辨率。