Wide coverage multi-beam receiving array calibration method

Abstract

The invention belongs to the field of multi-beam receiving array calibration, and in particular relates to a wide coverage multi-beam receiving array calibration method. A multi-beam sounding sonar receiver circuit and a transducer array are used as the whole to measure the matrix directivity. After the system is fully warmed up, the influence of the temperature drift of the circuit is eliminated,so that the system is in a daily working state, and it is not necessary to separately measure characteristics of each extension. The measurement process adopts an automatic one-way non-stop rotationmethod, and the data acquisition is controlled by a signal synchronization line, the sampling time is accurately benchmarked, and the mechanical rotation idle running error is excluded. The array calibration is performed by using a near-field focused beamforming algorithm, and an array beam directivity curve and a beam angle error curve are calculated in a small-sized muffler pool. The response capability of the wide-coverage multi-beam receiving array to echoes at various angles can be effectively characterized, the receiving transducer array and the signal conditioning circuit are integrallymeasured; and the method can accurately reflect the overall signal response capability of the receiving system, and can be widely used in the field of multi-beam receiving array calibration.

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 seabed topography and landform information in the area of ​​​​interest as basic data and supporting evidence. Multi-beam bathymetric sonar has become one of the most important marine survey and survey instruments in domestic and foreign marine scientific research, seabed resource development, marine engineering construction and other marine activities. [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 gradually increasing. For the ...

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.

Images