Measurement Improvement of Distributed Optical Fiber Sensor via Lorenz Local Single Peak Fitting Algorithm

Symmetry

Xiaoxue Wang¹  Jianping He²  Jianan Yu²  Yinping Zhang²  Shihai Zhang³  Bin Liu³ 

[1] Dalian Bo Ruixin Technology Limited, Dalian 116024, China;School of Civil Engineering, Dalian University of Technology, Dalian 116024, China;School of Mathematics and Physics, Nanyang Institute of Technology, Nanyang 473001, China;

关键词: optical fiber sensor;    Brillouin gain spectrum;    Brillouin frequency shift;    Lorenz local single peak fitting algorithm;    signal symmetry;   

DOI  :  10.3390/sym13071166

来源: DOAJ

【 摘 要 】

Brillouin frequency shift (BFS) of distributed optical fiber sensor is extracted from the Brillouin gain spectrum (BGS), which is often characterized by Lorenz type. However, in the case of complex stress and optical fiber self damage, the BGS will deviate from Lorenz type and be asymmetric, which leads to the extraction error of BFS. In order to enhance the extraction accuracy of BFS, the Lorenz local single peak fitting algorithm was developed to fit the Brillouin gain spectrum curve, which can make the BSG symmetrical with respect to the Brillouin center frequency shift. One temperature test of a fiber-reinforced polymer (FRP) packaged sensor whose BSG curve is asymmetric was conducted to verify the idea. The results show that the local region curve of BSG processed by the developed algorithm has good symmetry, and the temperature measurement accuracy obtained by the developed algorithm is higher than that directly measured by demodulation equipment. Comparison with the reference temperature, the relative measurement error measured by the developed algorithm and BOTDA are within 4% and 8%, respectively.

【 授权许可】

Unknown