Method for estimating frequency-band-division direction of underwater broadband sound source across ice layers through single detector

Abstract

The invention relates to underwater acoustic signal processing, in particular to a method for estimating the frequency-band-division direction of an underwater broadband sound source across ice layers through a single detector. Corresponding requirements are put forward for the performance of the single detector, and windowing frequency division processing is carried out on underwater ice water sound source emission signals in three directions picked up by the single detector above an ice layer; correlation filtering is carried out on the received signals in the horizontal direction and the vertical direction; rotation analysis and searching the maximum radial energy are performed to obtain the orientation estimation of the sound source in the water under ice; 180-degree fuzziness correction is carried out on the horizontal azimuth angle corresponding to the maximum energy; the determined horizontal azimuth angles of all the frequency bands are marked on the same azimuth map to obtain all azimuth estimations within the frequency band range of 40Hz-1kHz; or marking is performed according to frequency bands to obtain azimuth estimation maps of different frequency bands. The problems that under the condition of sea ice coverage, a hydrophone array or a vector hydrophone is difficult to arrange, and flow noise in water and other underwater noise interfere with target sound source signals in water are solved. The method is easy to arrange, fast in response to an under-ice moving target sound source, small in interference, economical and practical.

Description

technical field [0001] The invention belongs to the technical field of underwater acoustic signal processing, and in particular relates to a method for estimating the azimuth of a broadband sound source in water by frequency divisions 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 actively develop and utilize marine resources and space, and use 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 capable of long-distance transmission in the ocean. Therefore, among numerous marine underwater detection, positioning and development equipment, acoustic waves and their vibration energy detection are the main technical means used. [0003] For the azimuth estimation of underwater sound sources, the con...

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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