The optimization of sensitivity of frequency response of interferometric fiber-optic hydrophones

One of the most important parameters of sonar array is its dynamic range determining, in particular, by the frequency response of the hydrophone sensitivity. When using piezoelectric hydrophones the response sensitivity is optimal, providing that the sea noise spectrum at the output of the spatial filtration unit is suppressed. The salient feature of sonar arrays with interferometric fiber-optic hydrophones is a tract overload that occurs at the lower signal level the higher its frequency is. In this paper we have analyzed the factors determining the limits of the dynamic range. The formulation of the problem for finding the optimal frequency response sensitivity of hydrophones was stated. Examples of optimal parameters calculations using two models (monotonically decreasing and resonant ones) for frequency response shape sensitivity were given. When the results obtained were compared it was apparent that taking into account the shape of the frequency response sensitivity allows expanding the dynamic range of sonar array with interferometric fiberoptic hydrophones (in the case being considered the range was 9 db wider).