{"title":"The design of sidelobe suppressed PVDF beamforming elements for high performance underwater multi-beam swath transducers","authors":"D. Huang, S. Boucher, R. Tancrell, A. Rougeau","doi":"10.1109/ULTSYM.1997.661758","DOIUrl":null,"url":null,"abstract":"In recent years, multi-beam systems have gained widespread acceptance as the hydrographic surveyor's tool of choice for many reconnaissance as well as survey applications. In this discussion, we present the design and performance of a multi-beam receiver and broad beam projector for a bathymetry system which can collect data 30 times faster than a typical single beam system. Performance requirements of the receiver at 200 kHz realized with PVDF elements which produce a 3 degree beamwidth and sidelobe level of -30 dB by shading the element electrode pattern. These light weight receiving element are mounted in a precision-molded housing to create 30 contiguous beams separated 3 degrees in elevation. Data from all 30 beams are collected simultaneously, and the well-controlled beam shape and low sidelobe minimize interference between the beams. The projector, required to insonify a fan beam 2.5 degrees by 127 degrees, was constructed from 330 PZT elements to achieve a source level of 228 dB re 1 /spl mu/Pa at 1 meter at 5 kW pulse power. With this design approach, artifacts common to electronically formed beams are eliminated. This simplifies signal processing, improves system accuracy, and lowers the overall system cost. Both theoretical simulations and experimental data for the Mills' Cross configuration of the projecting and receiving elements, the system design principles, theoretical prediction, laboratory test and field measurements on various underwater topologies are presented.","PeriodicalId":6369,"journal":{"name":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1997-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"1997 IEEE Ultrasonics Symposium Proceedings. An International Symposium (Cat. No.97CH36118)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/ULTSYM.1997.661758","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 1
Abstract
In recent years, multi-beam systems have gained widespread acceptance as the hydrographic surveyor's tool of choice for many reconnaissance as well as survey applications. In this discussion, we present the design and performance of a multi-beam receiver and broad beam projector for a bathymetry system which can collect data 30 times faster than a typical single beam system. Performance requirements of the receiver at 200 kHz realized with PVDF elements which produce a 3 degree beamwidth and sidelobe level of -30 dB by shading the element electrode pattern. These light weight receiving element are mounted in a precision-molded housing to create 30 contiguous beams separated 3 degrees in elevation. Data from all 30 beams are collected simultaneously, and the well-controlled beam shape and low sidelobe minimize interference between the beams. The projector, required to insonify a fan beam 2.5 degrees by 127 degrees, was constructed from 330 PZT elements to achieve a source level of 228 dB re 1 /spl mu/Pa at 1 meter at 5 kW pulse power. With this design approach, artifacts common to electronically formed beams are eliminated. This simplifies signal processing, improves system accuracy, and lowers the overall system cost. Both theoretical simulations and experimental data for the Mills' Cross configuration of the projecting and receiving elements, the system design principles, theoretical prediction, laboratory test and field measurements on various underwater topologies are presented.
近年来,多波束系统作为水文测量员在许多勘测和测量应用中的首选工具得到了广泛的认可。在这篇讨论中,我们提出了一个测深系统的多波束接收器和宽波束投影仪的设计和性能,它的数据收集速度比典型的单波束系统快30倍。使用PVDF元件实现200 kHz时的接收机性能要求,通过遮蔽元件电极图案,产生3度波束宽度和-30 dB的副瓣电平。这些重量轻的接收元件安装在一个精密模制的外壳中,形成30个连续的梁,在3度的仰角上分开。同时采集30个波束的数据,良好的波束形状控制和低旁瓣最大限度地减少了波束之间的干扰。投影仪需要对2.5度乘127度的风扇光束进行消谐,由330 PZT元件构成,在5 kW脉冲功率下,在1米处达到228 dB re /spl mu/Pa的源电平。采用这种设计方法,消除了电子成形光束常见的伪影。这简化了信号处理,提高了系统精度,降低了整体系统成本。介绍了发射和接收单元的米尔斯交叉构型的理论模拟和实验数据,系统设计原则,理论预测,实验室测试和各种水下拓扑的现场测量。