Near-field wide-view-angle beam forming method of real-time three-dimensional imaging sonar

Abstract

The invention belongs to the technical field of three-dimensional sonar, and discloses a near-field wide-view-angle beam forming method of real-time three-dimensional imaging sonar. The near-field wide-view-angle beam forming method comprises the following steps that an echo sampling data matrix S of a sonar system is obtained; a time delay weighting coefficient k1 of a focusing target point inside a Fresnel time delay area and a time delay weighting coefficient k2 of the focusing target point outside the Fresnel time delay area are calculated; echo sampling data are subjected to L-point discrete Fourier transformation, and thus an echo signal S(l) is obtained; the echo signal S(l) is subjected to amplitude weighting and phase compensation, and thus a compensated echo signal tilde{S(l)} isobtained; .and the compensated echo signal tilde{S(l)} is subjected to fast Fourier transformation, an expression of the spatial beam intensity is obtained, and the spatial beam intensity is calculated. As for the situations that the focusing target point is located outside the Fresnel time delay area and located in a set imaging view angle range, the time delay weighting coefficients are optimized through a least squares method, under the premise of ensuring near-field beam forming calculation efficiency, near-field focusing accuracy can be effectively improved, and the view angle of near-field imaging is expanded.

Description

technical field [0001] The invention belongs to the technical field of three-dimensional sonar, and more specifically relates to a near-field wide-angle beam forming method of a real-time three-dimensional imaging sonar. Background technique [0002] Real-time 3D imaging sonar is a 3D acoustic imaging device developed in recent years to meet the growing demand for 3D detection of underwater targets. This type of 3D sonar has good imaging resolution and real-time imaging performance. There are a wide range of application requirements in engineering operations, marine scientific research, and national defense and military fields. Its basic imaging principle is: the system uses a narrow-band acoustic pulse to transmit the entire observation scene, uses phased array technology to simultaneously generate tens of thousands of real-time beam intensity signals, and obtains a three-dimensional scene image through real-time signal processing. The core technology of the imaging system...

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Problems solved by technology

[0005] Aiming at the above defects or improvement needs of the prior art, the present invention provides a near-field wide-angle beamforming method for real-time three-dimensional imaging sonar, wherein based on the Fresnel approximation time delay, the Fresnel approximation time delay is calculated by using the least square method The parameter optimization of the near-field imaging area beyond the scope of application of the theory can effectively solve the problems of narrow detection area and low near-field focusing accuracy, so it is especially suitable for the application of near-field area target imaging

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