Study And Design On The Virtual Detection System For Interferometric Fiber-Optic Hydrophone

The fiber optic hydrophone is a science of high-tech based on optical fibersensing technology, involving communication signal processing, automatic control,measurement etc. It is widely used in the military field with the rapid development.Various signal detection technologies have been made more progress from analog todigital detection as demand of high-performance are increasing for fiber optichydrophone. With the development of virtual instrument technology, the virtualmeasuring signal of fiber optic hydrophone makes a new kind of method.The interferometric fiber-optic hydrophone theory is firstly discribed in thisthesis. And the3x3coupling demodulation theory and its mathematical model areanalyzed and compared. Also, a virtual detection scheme is designed. The dataacquisition program for the hs3-100card is developed by calling DLL on LabVIEW.Afterwards, a data processing and displaying program is developed according to theprogram model of "production-consumers" and the design concept of modularity.Finally, the ITT virtual measuring system for the interference fiber optic hydrophonehas been successfully developed.HS3-100card can acquisit data at high-speed and in real-time by calling DLL.Through the simulation of three output signals, the performance of the interferometricfiber–optic hydrophone has been verified. Simulation test is smoothly achieved and ithas shown that the virtual measuring system has a strong resistance to the amplitudedrift of DC voltage and the movement of AC magnitude. Morever, it has a bettertorlerence for the signal phase error. The experiment has demonstrated that the virtualdetection system has good acoustic pressure sensitivity and the acceleration sensitivity,which accords with the industry standards of measurements. Finaly, some referentialsuggestions are put forward for improvement and further research.