Underwater acoustic applications

由于声波在水中的吸收率低，经常被用于各种海洋变量的遥感、海底沉积物分类、海洋水深测量、鱼类资源评估、水声通信、导航和定位。这些应用中的大多数都需要对水声信道有很好的了解，并需要对信号压缩、传输和接收的复杂算法有很好的了解。在混响强烈的、时变的水下信道中，声传输通常需要自适应接收器与自适应声束形成和跟踪相结合。这在浅海传输中尤其相关。精确的声学导航和多波束声测深需要高效的声线跟踪算法。由于与声传感相关的大量数据需要有效的压缩来传输或存储。因此，任何实际的声传感系统设计都必须解决这些问题。拟议的研究将认识到所有这些问题，但它将集中于用于水下平台的精确导航和定位的新的声学方法，如海底爬行器和各种水下机器人。这样的平台越来越频繁地用于海洋研究、海底探测和海洋观测系统，如海王星加拿大计划和其他几个计划。将开发新的传输和信号处理方法，以实现现有系统无法达到的精度。要解决的具体应用还包括测量板块移动，其中所需的精度是以毫米为数量级的距离，以公里为数量级。要达到如此非凡的精度，需要对这种测量采取新的方法。另一个研究领域将集中在利用深度探测仪和侧视声纳进行海底表征和分类的新方法。海底类型及其地形的测绘对于渔业、鱼类资源评估和其他海洋勘探领域具有重要意义。

Due to their low absorption in water, acoustic waves are frequently used for remote sensing of various oceanographic variables, bottom sediment classification, ocean bathymetry, fish stock assessment, underwater acoustic communication, navigation and positioning. Most of these applications require good understanding of underwater acoustic channels and sophisticated algorithms for signal compression, transmission and reception. Acoustic transmissions in highly reverberant, time-varying underwater channels often require an adaptive receiver combined with adaptive acoustic beam forming and tracking.  This is particularly relevant in shallow water transmissions.  Efficient acoustic ray tracing algorithms are needed for precise acoustic navigation and multi-beam acoustic bathymetry.  The large amounts of data associated with acoustic sensing require efficient compression for transmission or storage.  Any practical design of acoustic sensing systems must address these problems. The proposed research will recognize all these problems but it will concentrate on novel acoustic methods for precise navigation and positioning of underwater platforms such as bottom crawlers and various underwater vehicles. Such platforms are more and more frequently used for ocean research, bottom inspection and in ocean observing system such as planned by Neptune Canada program and several others. New methods for transmission and signal processing will be developed to achieve precisions not attainable by presently available systems. Specific applications to be addressed include also measurements of plate movements where required precision is in order of millimeters over distances in order of kilometers. Achieving such an extraordinary accuracy require new approaches to such measurements. Another area of research will concentrate on new methods for bottom characterization and classification using depth sounders and side-looking sonars. The mapping of bottom type and its topography is important for fisheries, fish stock assessment and other area of ocean exploration.