Amplitude-phase error correction method for phased array three-dimensional camera shooting sonar system energy converter array

Abstract

The invention discloses an amplitude-phase error correction method for a phased array three-dimensional camera shooting sonar system energy converter array. The method comprises the following steps: utilizing two-dimensional fast Fourier transform to acquire original estimation of normalization angular frequency for two-dimensional compound sampling array of a kth sampling snapshot; based on the original estimation, acquiring the estimation value of the normalization angular frequency with higher precision in various sampling snapshots; conducting arithmetic mean on the estimation value of the normalization angular frequency of K times sampling snapshots so as to acquire the robust estimation of the orientation of a corrected source; utilizing the robust estimation and the spatial matched filtering algorithm to estimate amplitude-phase error factors of various energy converter passages in an energy converter array; utilizing the amplitude-phase error factors to compensate compound sampling signals in various energy converter passages, and finally utilizing the number wave beam forming algorithm to acquire three-dimensional camera shooting sonar wave beams going through amplitude-phase error correction. The amplitude-phase error correction method avoids heavy and complicated iteration and matrix manipulation and is small in calculated amount and suitable for on-site correction of large energy converter array in a three-dimensional sonar system.

Description

technical field [0001] The invention relates to the technical field of a phased array three-dimensional camera sonar system, in particular to a method for correcting amplitude and phase errors of a transducer array of a phased array three-dimensional camera sonar system. Background technique [0002] The phased array three-dimensional camera sonar system uses a two-dimensional uniform rectangular transducer array containing thousands of array elements to receive echo signals, and then uses beamforming technology and real-time image processing technology to obtain high-resolution underwater three-dimensional images. [0003] Affected by the limitation of processing technology level and the inevitable temperature and / or humidity changes, thermal effects, device aging and other factors in actual engineering applications, the hydrophone and signal conditioning of different transducer channels in the phased array 3D camera sonar system There is inconsistency in the performance of...

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Problems solved by technology

[0006] Common array error automatic correction methods usually use alternate iterative algorithms to jointly estimate the correction source azimuth and array amplitude and phase errors, but the iterative algorithm usually has a large amount of calculation, and the global convergence performance is not easy to guarantee

[0007] The auxiliary array elements in the prior art or the array calibration method for partial calibration arrays can obtain good calibration accuracy, but this type of method is difficult to apply to the phased array 3D camera and sonar system sealed in a watertight chassis

[0008] In addition, there is another type of amplitude-phase error correction algorithm for uniform rectangular arrays, which uses the Toeplitz-block structure of the data covariance matrix, but the correction accuracy of the algorithm still needs to be improved, and the algorithm has a limited scope of application; at the same time, for phase control For a large uniform rectangular transducer array in an array 3D camera sonar system, the amount of calculation required for the automatic correction algorithm is also an important issue that needs to be considered in field applications

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