Super-resolution image reconstruction-based synthetic aperture sonar imaging method

Abstract

The invention discloses a super-resolution image reconstruction-based synthetic aperture sonar imaging method, which comprises: expanding aperture according to an original sonar aperture array; dividing the expanded aperture into sub apertures; estimating the round trip time of detecting acoustic waves; orthogonally encoding transmission acoustic waves and detecting a target water area; and imaging the target water area with a super resolution. In the invention, a high-resolution sonar image is obtained by combining super-resolution image reconstruction technology and SAS processing technology. Compared with synthetic aperture sonar before expansion, the expanded synthetic aperture sonar has improved resolution in terms of direction and distance; and compared with the conventional synthetic aperture sonar technology of the same aperture, the expanded synthetic aperture sonar has improved resolution in terms of direction and distance.

Description

technical field [0001] The invention relates to the field of synthetic aperture sonar (SAS), in particular to a synthetic aperture sonar imaging method based on super-resolution image reconstruction technology. Background technique [0002] With the continuous development of science and technology, the scope of human activities is also expanding, and countries all over the world are paying more and more attention to marine scientific research. There is an increasing demand for underwater terrain detection and underwater object observation. In the development of seabed mineral resources, engineering survey and underwater operation monitoring are required; in the negotiation of maritime rights and interests demarcation with other countries, the support of corresponding seabed topography and geomorphology data is required; channel dredging projects also require seabed topography and geomorphology surveys and engineering quantities. Assessment; there are many important human un...

AI Technical Summary

Problems solved by technology

In order not to change the surveying rate, the existing solution is to add n receiving subarrays behind the sonar platform, that is, multi-subarray SAS technology, then the volume of the system will increase by n times, and there is a computational load in the multi-subarray SAS imaging algorithm Disadvantages such as poor imaging effect caused by large and neglected corresponding errors

[0006] (2) In the distance direction, the resolution of SAS is related to the pulse width of the detection sound wave. The narrower the pulse width (that is, the shorter the pulse duration), the higher the distance resolution, but the pulse duration is about the reciprocal of the pulse width, that is Improving the distance resolution of SAS requires increasing the transmission bandwidth of the transducer. For example, every time the pulse duration is reduced by half, the pulse bandwidth needs to be expanded to twice the original bandwidth. Higher bandwidth requirements increase the difficulty of transducer manufacturing. At the same time, the higher the frequency of underwater sound waves, the faster the power attenuation, the lower the signal-to-noise ratio, the increased impact of ocean noise, and the worsening of imaging quality. If the original imaging quality and signal-to-noise ratio are to be maintained, the The underwater acoustic transducer detects the emission power of sound waves

Due to the difficulty and high cost of manufacturing high-power broadband underwater acoustic transducers, the further improvement of the existing SAS range resolution is limited.

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