A method for sub-band azimuth estimation of broadband sound sources in water with a single detector across the ice layer

Abstract

A method for azimuth estimation of broadband sound sources in water across the ice layer with a single detector, involving underwater acoustic signal processing. Corresponding requirements are put forward for the performance of the single detector. The three directions of the sound source emission signals in the sub-ice water picked up by the single detector above the ice layer are subjected to windowing and frequency division processing: horizontal and vertical correlation filtering of the received signal; rotation analysis and analysis. Find the maximum radial energy, and obtain the azimuth estimation of the sound source in the subglacial water; the horizontal azimuth corresponding to the maximum energy is corrected by 180° ambiguity; the horizontal azimuth determined by each frequency band is marked on the same azimuth map to obtain 40Hz~1kHz All azimuth estimates within the frequency band; or sub-frequency bands are marked to obtain azimuth estimates for different frequency bands. Solve problems such as difficulties in the deployment of hydrophone arrays or vector hydrophones, and the interference of water flow noise and other underwater noises on the target sound source signal in the water under the conditions of sea ice coverage. Easy to deploy, fast response to moving target sound sources under ice, less interference, and economical.

Description

technical field [0001] The invention belongs to the technical field of underwater acoustic signal processing, in particular to a method for estimating the sub-band azimuth of a broadband sound source in water across an ice layer with a single detector. Background technique [0002] With the development of human civilization, the strategic position of the ocean has become increasingly prominent. Countries are actively developing and utilizing marine resources and space, using various means to detect, research and develop the underwater environment of the ocean, and to detect and locate underwater targets. Acoustic waves are currently the only form of energy that can propagate over long distances in the ocean. Therefore, in numerous marine underwater detection, positioning and development equipment, the detection of acoustic waves and their vibrational energy is the main technical means used. [0003] For the azimuth estimation of underwater sound sources, the conventional met...

AI Technical Summary

Problems solved by technology

For the deterministic signals received by underwater multi-array elements, although the sound source azimuth can be estimated through band-pass filtering and various improved music algorithms, there will be problems when using a single three-dimensional geophone to estimate the sound source azimuth of an underwater target. To the following technical difficulties: First, because the sound waves emitted by the target sound source under the ice need to pass through the ice layer to reach the ice receiver, the propagation of sound waves in the ice layer and the acoustic reflection characteristics of the water-ice interface will strongly affect Azimuth Estimation of Sound Sources Under Ice

Secondly, the ice layer will change over time. Some sea ice may contain a large number of non-uniform melting pools and brine bubbles. In particular, the physical properties of first-year ice and multi-year ice in the Arctic are quite different. When propagating in these ice layers, different reflection, scattering and transmission characteristics, as well as propagation attenuation and other issues, will also have different effects on the azimuth estimation of underwater sound sources. Complex acoustic coupling problems will occur between the ice interface and the water-ice-air structure, which will eventually make it difficult to estimate the azimuth of the broadband sound source under the ice

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