浅海大孔径时钟弱同步阵列的信道匹配阵形校准  

A channel matching shape-estimation method for a large aperture array with loose time synchronization in shallow water

作　　者：何琪 宫在晓[1] 李风华[1] 郭良浩[1] 李整林 江磊[1] 王光旭[1] HE Qi;GONG Zaixiao;LI Fenghua;GUO Lianghao;LI Zhenglin;JIANG Lei;WANG Guangxu(State Key Laboratory of Acoustics,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190;University of Chinese Academy of Sciences,Beijing 100049;School of Ocean Engineering and Technology,Sun Yat-sen University,Zhuhai 519000)

机构地区：[1]中国科学院声学研究所,声场声信息国家重点实验室,北京100190 [2]中国科学院大学,北京100049 [3]中山大学,海洋工程与技术学院,珠海519000

出　　处：《声学学报》2023年第1期5-15,共11页Acta Acustica

基　　金：国家自然科学基金项目(11874061,12174418,12104481,12204508);中科院青年创新促进会项目(E229110301)资助。

摘　　要：浅海大孔径时钟弱同步阵列的阵形校准,受到时钟偏移与信道频散的不利影响,校准精度难以满足探测要求。利用浅海波导环境中仅激发一阶模态的低频段校准信号,使用基于波导参数计算的相速度开展信道匹配距离测量,并将时钟偏移作为未知参数纳入校准模型,结合声源与参考阵元的位置信息,从而消除频散效应和时钟偏移的不利影响,可实现浅海大孔径阵列阵元位置与时钟偏移的信道匹配联合校准。实验数据分析结果表明,该方法有效校准浅海大孔径时钟弱同步阵列的阵元位置和时钟偏移,较之基于时延估计的传统方法,所提方法校准后的15阵元860 m大孔径水平线阵列,对正横和端射方向附近15~30 Hz目标信号的测向精度分别提高了0.2°和0.4°,阵增益分别提高了1.8 dB和4.4 dB。Accurate Shape-estimation for a large-aperture bottom-mounted array in shallow water is required for the target detection,which is often degraded by the channel dispersion and asynchronous clock.A shape estimation method is proposed for a large-aperture bottom-mounted array whose elements are loosely synchronized in time.The low-frequency active emissions,which excite only the first order normal modes in the waveguide,are used as the calibration signals.The phase velocity across the frequency band is calculated based on the channel parameters,and used to eliminate the negative influence of the modal dispersion.With the GPS information of the sources and the reference array element,the element positions as well as their clock offsets are estimated.The experimental data are used to demonstrate the superior performance of the proposed method for the array shape and clock offset estimation for various parameter-mismatched scenarios.The results on real data collected at sea with a 860-m-long array with 15 sensors demonstrate that the accuracy of the direction-of-arrival estimation and the array gain are improved by 0.20 and 1.8 dB for the broadside targets,0.4°and 4.4 dB for the end-fire targets respectively.

关 键 词：时钟偏移 时延估计 线阵列 测向精度 实验数据分析 阵形 大孔径 频散效应 

分 类 号：TB56[交通运输工程—水声工程]