A noise reduction method based on F-K transform for optical fiber hydrophone towed array

Abstract

Optical fiber hydrophones have many technical advantages, such as: large dynamic range, no electricity in the wet-end, small diameter under zero-buoyancy restriction, and so on. These merits make the optical fiber hydrophone more suitable to towed array for small vehicle. But the problem is that the optical fiber hydrophone outputs more extraneous noise than the piezoelectricity hydrophone when used in a towed array, due to its sensing mechanism. Aimed at this, a noise reduction method based on F-K transform is proposed in this paper in order to increase the Signal to Noise Ratio (SNR). Together with the multi-scale filter and Radon transform, most noise is removed and the signal components are reserved. The method is validated by both simulation and sea experiment data, and the results show that in the 80-120Hz bandwidth this method improves SNR by about 4~9dB.