多波束声呐基阵一体化自校准方法

Research on the self-calibration of multi-beam echo sounder transducer array based on the integrated method

为了保证多波束测深系统的探测精度,在系统组装前需要对多阵元接收换能器基阵进行指向性测量和目标方位波束响应校准。针对常规方法中图像散焦问题存在的不足,本文提出了一种多波束声呐基阵一体化自校准方法,将换能器基阵和信号调理采集电路一体化测量,利用目标方位波束响应输出测量换能器基阵波束指向性。推导了阵元间距误差对测深结果产生的影响,采用聚焦波束形成技术,在小尺寸水池条件下开展校准实验研究。通过在水池中预先获得的方位波束角误差曲线,对多波束测深声呐外场实验数据进行了归位补偿,实现了多波束声呐基阵一体化自校准。实验结果表明:该方法能够保障多波束声呐的有效覆盖范围,具有较强的实用性和重要的工程应用价值与推广价值。

To ensure detection precision of the multi-beam detection system,the directivity of the multi-element transducer array needs to be measured and the beam response in the object direction needs to be calibrated before the system is assembled. The conventional array directivity measurement methods usually assume that the received signal fits the far-field plane wave model. In this paper,we analyze the defocus problem caused by far-field approximation and deduce the depth error caused by the element spacing error. We propose a novel self-calibration method for multi-beam echo sounder( MBES) transducer array that is based on the method of focused beamforming to overcome the deficiencies of conventional method. An experiment was carried out in a small-size tank,and the field experimental data was compensated by the beam angle error curve obtained in the tank experiment. The experimental results demonstrated that the proposed self-calibration approach can guarantee the coverage of the MBES system;thus,the method has strong practicability and high engineering value and can therefore be promoted.