Acoustic multibeam system for 3-dimensional bedform evolution studies

用于 3 维床形演化研究的声学多波束系统

• 批准号: 345318-2007
• 负责人: Hay, Alexander
• 金额: $ 3.87万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments - Category 1 (<$150,000)
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=364753
• 关键词: Acoustic; multibeam; system; dimensional; bedform

The equipment requested is a high-frequency acoustic multibeam system for obtaining high-resolution profiles of the seafloor at frame rates approaching that of video systems. The bed elevation profile is obtained by steering the acoustic beam spot electronically over the seafloor. Based on an earlier design operating at an acoustic frequency of 260 kHz (6-mm wavelength), this newly-developed Canadian-built sensor operates at 2.25 MHz (0.7-mm wavelength), the shorter wavelength providing much higher spatial resolution. To obtain a 3-dimensional map, the acoustic sensor must be mechanically driven in a direction orthogonal to the beam-steering plane, and thus funds are also requested to purchase a rotator unit for this purpose.   The combined multibeam/rotator system will be capable of generating 3-d maps of the small-scale seafloor topography over a 5-m by 5-m area with a horizontal resolution of a few cm or better, and better than 1-cm vertical resolution, in tens of seconds. Given the 10-s typical periods of wind-generated sea-and-swell waves, this acquisition time is commensurate with the passage of several surface gravity waves. Thus, the system will enable first-time investigations of the evolution of mobile seafloor topography on the time scales of wave-groups. The system will be deployed in the fall of 2007 for 2 months as part of an investigation of the temporal evolution of wave-formed ripples on inner shelf in coarse- and fine-grained sands.

该设备是一种高频的多束，用于以较早的设计在电子方式上通过电子方式来获得床的高度率这种新开发的加拿大传感器以260 kHz（6毫米波长）的声音频率运行，以2.25 MHz（0.7毫米长）运行，较短的波长可提供高度高的高空间分辨率。尺寸地图，声音传感器必须以机械的方式朝向梁驱动平面旋转单元的方向驱动，以便在5 d-d地图上生成5-D地图。 -m鉴定有几秒钟的水平分辨率，鉴于10 s的典型时期，这是风产生的海上绿色波浪在波动组的时间尺度上，该系统的移动海底地形的演变将被部署在圆锥形的扑通量中，以圆锥形的圆形架子和细粒砂中的波形纹身。