Statistical characteristic of spectrum for ambient noise at high frequencies in shallow water

Abstract

As a kind of commonly background signal, Ocean ambient noise is interference in the underwater acoustic channel. Although there are a lot of marine noise sources, the parameter influencing ocean ambient noise field are closely related to the state of the marine environment. From the perspective of theory, the change law of the ocean ambient noise at a fixed-point was difficult to describe. And from the perspective of experiment, some characteristic of the accurate ocean ambient noise cannot be measured at all. And even if the ocean ambient noise have been obtained, the data was still useless. Therefore, this paper would make an intensive study on the random characteristic of ocean ambient noise, and discuss the statistical analysis method, which including the mathematical expectation, the variance, the power spectral density and so on. In this paper, the bottom-placed hydrophones were employed to measure the marine environmental noise for 12 months in a shallow sea continuously. Then the test data was correspondingly processed, and the spectral characteristic of the ocean ambient noise in high frequency 10∼35 kHz was accordingly obtained. The results of this study would be of great significance for the offshore platform in shallow sea.