Study On Distributed Fiber Optic Sensing System Data Acquisition

Distributed optical fiber sensing technology gradually attracted attention of domestic research institutions, has been in the field of mining, dams and electricity transmission considerable engineering applications, rapid development, and produced better social and economic benefits.First of all, the paper introduces the principle of optical fiber sensor based on Rayleigh scattering, Raman scattering and Brillouin scattering distributed optical fiber sensing technology, and discusses Rayleigh scattering optical fiber sensing system. Then, we analyzed data processing algorithmsbased on wavelet transform and wavelet de-noising technology on the matlab simulation,simulation results showed that the wavelet technology can greatly improve the signal to noise ratio, thereby improving system performance.We studied the distributed optical fiber sensing system technology, which were based on the Visual C ++ 6.0 development of the Microsoft environment and PCI data acquisition card, and built the circuit portion of the OTDR data acquisition system. We mainly carried out the following work for the OTDR data acquisition system:1 In the data acquisition hardware initialization module,we used code achieving the data acquisition card data acquisition hardware parameters and initial configuration; 2 In the data acquisition file operations module, we completed the reading and writing txt, wav and date types of data files, and data analysis to extract data from the backend on the Visual C ++ 6.0 development of the Microsoft environment; 3 In the data acquisition front-end interface operation module, we completed the coordination of cross-ordinate, the underlying hardware of the Data acquisition card, sensing fiber distance placement test of the OTDR data acquisition system and Rayleigh backscatter signal strength, and used the double buffer technology to achieving the coordination of between data storage and data. 4 Using sine wave tests the OTDR data acquisition system performance, and accurately located the optical fiber connector point and fiber pigtail location of the 5km、10km optical fiber.5 Combining results and programming technology, we analyzed the use of software for OTDR data acquisition system’s strengths and weaknesses, and given the key code.Combined OTDR data collection technologies and programming techniques, we focus on the data collection technology of the OTDR system, analyaed each module of the system spatial resolution and signal to noise ratio, and used OTDR data acquisition equipment and software technology to completed the building of OTDR Data Acquisition System and the testing experiment.