Low-frequency remote three-dimensional imaging method based on acoustic orbital angular momentum

Abstract

The invention relates to a low-frequency remote three-dimensional imaging method based on acoustic orbital angular momentum. The method comprises the following steps of: constructing an acoustic orbital angular momentum super-resolution three-dimensional imaging sonar; emitting a vortex sound field which is non-uniformly distributed in the circumferential direction by the acoustic orbital angularmomentum super-resolution three-dimensional imaging sonar and receiving echo signals reflected by a remote target; respectively carrying out primary beam forming on a pitch angle and an azimuth angleto obtain a series of two-dimensional sonar image slices in the area, and synthesizing the series of slices in the distance direction to obtain three-dimensional sonar imaging; and respectively carrying out secondary beam forming on the pitch angle and the azimuth angle to obtain a super-resolution three-dimensional image. According to the invention, high detection precision can be generated by using low detection sound wave frequency, the imaging resolution can be improved, and the difficulty of short detection distance caused by the condition that the higher the detection sound wave frequency is and the faster the attenuation of the detection sound wave in water is can be overcome.

Description

technical field [0001] The invention belongs to the technical field of marine acoustic equipment, and relates to a three-dimensional imaging sonar technology, in particular to a low-frequency remote three-dimensional imaging method based on acoustic orbital angular momentum. Background technique [0002] The high-precision three-dimensional detection technology of underwater targets has very urgent application requirements in national defense and military fields such as port and navigation safety, underwater engineering, emergency rescue, and underwater vehicle confrontation. However, due to the serious propagation attenuation of electromagnetic waves in the water environment, the common optical and electromagnetic detection technologies on land and in the air have low usability underwater. Underwater 3D sonar imaging technology is one of the most important innovations in various sea-related industries in recent years. It can conduct multi-angle, high-resolution continuous o...

AI Technical Summary

Problems solved by technology

This type of three-dimensional imaging sonar has been developed by the United States, the United Kingdom, and Norway. The working distance can cover hundreds of meters, but the research and development threshold is high, and it faces some bottleneck problems: (1) The hardware system is extremely complex, requiring thousands of Transducers and signal processing circuits are difficult to realize in terms of technology; (2) The imaging resolution is 1-2 orders of magnitude lower than that of optical imaging, and it is difficult to further improve due to the limitation of the aperture size of the sonar carrier; (3) The imaging angle of view is limited Limited to algorithmic limitations, it is difficult to effectively expand

However, the higher the frequency of the detection sound wave, the faster the attenuation in water and the shorter the propagation distance. Therefore, in order to ensure the detection accuracy, it is impossible to detect a longer distance

Images