A wide coverage multi-beam receiving array calibration method

Abstract

The invention belongs to the field of multi-beam receiving array calibration, in particular to a wide-coverage multi-beam receiving array calibration method. The multi-beam sounding sonar receiver circuit and the transducer array are used as a whole to measure the directivity of the array. After the system is fully warmed up, the influence of circuit temperature drift is eliminated, so that the system is in a daily working state, and there is no need to measure each extension separately. characteristic. The measurement process adopts the automatic one-way non-stop rotation method, and the data acquisition is controlled by the signal synchronization line, and the sampling time is accurately aligned to eliminate the mechanical rotation idling error. The array is calibrated using a near-field focused beamforming algorithm, and the beam directivity curve and beam angle error curve of the array are calculated in a small anechoic tank. It can effectively characterize the response ability of the wide coverage multi-beam receiving array to echoes from various angles, and integrate the receiving transducer array with the signal conditioning circuit to measure the overall signal response ability of the receiving system more truly. It is widely used in Multi-beam receiver array calibration field.

Description

technical field [0001] The invention belongs to the field of multi-beam receiving array calibration, in particular to a wide-coverage multi-beam receiving array calibration method. Background technique [0002] In scientific research, resource development, engineering construction, and military activities around the ocean, it is usually necessary to accurately obtain the information of the seabed topography in the area of ​​interest as the basic data and supporting basis. Multi-beam bathymetry sonar has become one of the most important marine survey instruments in marine activities such as marine scientific research, seabed resource development, and marine engineering construction at home and abroad. [0003] The development of multi-beam bathymetric sonar is gradually developing towards the direction of wide coverage, high precision and integrated measurement, so the accuracy requirements for the receiving transducer array are also gradually improved. For the wide coverage...

AI Technical Summary

Problems solved by technology

This measurement method does not coincide with the multi-beam sounding mechanism. The multi-beam sounding algorithm needs to perform beamforming first, so it is more concerned about the directivity output of the matrix at each beam angle, and the natural directivity cannot represent this characteristic.

In addition, the traditional method requires the base array to be under the assumption of a far-field plane wave, so that the signals of each array element can be equivalent to non-directional direct superposition. When the operating frequency of the base element is low, the far-field distance is relatively long, requiring a huge pool size

The traditional matrix calibration method only simply corrects the characteristics of the transducer without considering the characteristics of the signal receiving circuit that is matched with it. The characteristics of the signal receiving circuit are generally measured separately. This measurement method has little effect on systems with fewer channels. It is obviously not suitable for multi-beam sounding systems with hundreds of receiving channels and different circuit amplitude and phase consistency

When conducting directivity measurement, it is generally necessary to place the transducer in the far-field condition under a large-scale pool to rotate the multi-degree-of-freedom telescopic rod. The measurement of each angle needs to rotate and pause the screw, which will introduce space. The range error has little effect on the directivity range measurement of large angles, but it will bring a large angular deviation to the multi-beam sonar beam directivity measurement that requires high precision.

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