Optical fiber hydrophone background noise self-adaptive offset method based on self-adaptive algorithm

Abstract

The invention discloses an optical fiber hydrophone background noise self-adaptive offset method based on a self-adaptive algorithm. The method comprises the steps: adding a reference interferometer which has the same structural parameters as a sensing Michelson interferometer and is insensitive to sound pressure in an optical system, and serving as a reference channel; acquiring the high-correlation noise introduced into each interferometer by a common noise source such as a light source, a circuit and the like; and then, offsetting a noise part, highly related to the reference signal, in the sound pressure signal by using a self-adaptive algorithm. The method is based on a self-adaptive noise offset method, the background noise tracking capability of the optical fiber hydrophone is improved, the background noise of the system is effectively reduced, and finally a clean sensing signal, namely the sound pressure signal, is obtained.

Description

technical field [0001] The invention relates to the technical field of noise elimination, in particular to a method for adaptively canceling background noise of an optical fiber hydrophone based on an adaptive algorithm Background technique [0002] With the development of acoustic "stealth" technology, the radiation noise of underwater targets has been continuously reduced, which poses new challenges for low-frequency and long-distance detection in shallow seas. The noise floor is one of the important indicators to measure the performance of the interferometric fiber optic hydrophone system, which determines the minimum measurable phase shift of the system, and thus directly determines its ability to detect weak low-frequency long-distance targets. At present, most of the fiber optic hydrophones that can meet the practical requirements adopt the fiber Michelson interferometer structure. In order to reduce the background noise of the system, many researchers studied various...

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Problems solved by technology

However, in practical applications, due to the influence of temperature and external environment, the phase signals of the reference interferometer and the sensing interferometer have different degrees of low-frequency random drift, so although the phase noise introduced by the laser into the two interferometers has a high waveform similarity , but not exactly the same

So the method of using cross subtraction is not ideal

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