Study On Frequency Response Characteristics Of Pressure Difference Fiber Optic Vector Hydrophone

The tiny difference between the presure at two points in space is approximately equal to the gradient of acoustic pressure.This principle has been used apply in using a gradient hydrophone to get vector information in an underwater acoustic field.Its sensing principle was theoretically analyzed,and a means for standing wave calibration was designed.Then theoretical analysis and a computer simulation of standing wave calibration for a gradient hydrophone were carried out.The result agreed well with theoretical analysis and the computer simulation.These studies should improve the range of application for gradient hydrophones.In this paper the design principle of the composition of pressure gradient hydrophone is based on optical fiber Michelson interferometer for sensing signal based on variable cylinder and diaphragm pressure induction vector hydrophone,to demodulate the sound field in the sound field and the sound pressure difference vector information to analyze electrical signals.In the sensing principle,differential pressure hydrophone to accept water pressure gradient information or particle velocity information of acoustic pressure sensor through variable ends of cylinders,and then the pressure information in the field through the variable cylinder conduction to the cylinders and cause smooth physical variable cylinder variable then by winding in cylinders at both ends of the optical fiber Michelson interferometer signal detected by the sensing arm volume deformation information and the deformation signal into the optical fiber interferometer in the light interference signal.Based on variable cylinder under static stress and strain analysis on the analysis of the deformation equation of variable cylinder along in the outside world under the sound pressure,and based on the analysis of pressure gradient hydrophone of variable cylinder diaphragm structure with composite fiber winding between acoustic coupling deformation under pressure the.At the same time,the principle of sound pressure phase shift sensitivity of vector hydrophone is put forward.Then analyze the influence of the design parameters on the pressure phase sensitivity of vector hydrophone,and the one by one and the computer simulation analysis is conducted for it's influence facts,and based on the analysis of the influence of resonant vector hydrophone in dynamic measurement under the condition of the vector measurement.Finally,based on the summary and the dynamic conditions of the pressure phase sensitivity are analyzed by simulation analysis in the front,and the influence of various elements of the output vector hydrophone phase shift are discussed and analyzed in detail.At the same time in the vector hydrophone sound-phase sensitivity frequency response analysisis based on the analysis of the vector hydrophone directivity curve under different the condition.