Forward-looking sonar Doppler beam sharpening method

A Doppler wave and forward-looking sonar technology, which is used in the re-radiation of sound waves, radio wave measurement systems, and the use of re-radiation, etc., can solve the problems of high cost, many receiving channels, and complex equipment.

Inactive Publication Date: 2017-07-07
NAVAL UNIV OF ENG PLA
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Problems solved by technology

But there are also many receiving channels (the international advanced forward-looking sonar has about 200 channels); the equipment is complicated and the cost is high.

Method used

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  • Forward-looking sonar Doppler beam sharpening method
  • Forward-looking sonar Doppler beam sharpening method
  • Forward-looking sonar Doppler beam sharpening method

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Embodiment Construction

[0015] The working principle of the present invention is: using the difference of Doppler frequencies of targets in different azimuths in the same beam to distinguish targets, and this technique is called Doppler Beam Sharpening (DBS).

[0016] However, the forward-looking sonar DBS is far more difficult to implement than the radar DBS: the forward-looking sonar pulse repetition frequency is low, and there is ambiguity in the Doppler center frequency and Doppler bandwidth. To realize the DBS of sonar, these two difficulties must be solved. The invention of the method firstly solves these two difficulties, so that DBS can be applied in sonar.

[0017] For forward-looking sonar DBS, the Doppler center ambiguity is inevitable and can only be eliminated by signal processing. This technology is called zeroing the target echo frequency at the beam center azimuth point (center frequency zeroing for short). The specific technical solution is: when performing distance migration correc...

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Abstract

The invention relates to a forward-looking sonar Doppler beam sharpening method. Multiple targets are distinguished by using the difference of Doppler frequencies of different azimuth targets in a same wave beam. In range migration correction, the phase compensation technology is used, center frequency zero setting is realized, and Doppler center frequency ambiguity is eliminated. A pulse repetition frequency is improved by reducing a coherence time and emitting orthogonal waveforms in turns, and Doppler bandwidth ambiguity is eliminated. Through the beam widening technology, the length of a synthetic aperture is expanded, a coherent accumulation time is increased, and a sharpening ratio is increased. According to the forward-looking sonar Doppler beam sharpening method, under a given condition, the forward-looking sonar imaging resolution can be effectively improved, under a condition of a given resolution, the size of a receiving array and the number of channels can be reduced, and the complexity of the system is reduced.

Description

technical field [0001] The invention belongs to forward-looking sonar, in particular to a method for sharpening the Doppler beam of the forward-looking sonar, which is used for improving the resolution of the forward-looking sonar, or reducing the number of receiving channels and system complexity. Background technique [0002] Forward-looking sonar is a commonly used image sonar, which is mainly used for mine hunting and side-scan sonar for blindness compensation and collision avoidance. The forward-looking sonar has the advantages of high resolution (the azimuth beam width is as low as 0.5 degrees), and the advantages of surveying and mapping scene images can be obtained with a single pulse emission. However, there are also a large number of receiving channels (the international advanced forward-looking sonar has about 200 channels); the equipment is complicated and the disadvantages are high. Contents of the invention [0003] The purpose of the present invention is to...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01S7/52G01S7/539
CPCG01S7/52003G01S7/539G01S15/50
Inventor 唐劲松吴浩然钟何平田振丘昌镇张森徐魁
Owner NAVAL UNIV OF ENG PLA
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