Ocean Acoustic Inversion

海洋声学反演

• 批准号: RGPIN-2015-06171
• 负责人: Dosso, Stan
• 金额: $ 2.4万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=613986
• 关键词: Ocean; Acoustic; Inversion

Oceans are opaque to electromagnetic waves but transparent to sound; hence, acoustics is used for many underwater applications such as the remote sensing of seabed properties/processes or the locations of sound sources (e.g., submarines, marine mammals), with geological, geotechnical, environmental and sonar/defence applications. However, acoustic remote sensing requires nonlinear inversion, with quantitative model selection and uncertainty estimation required for meaningful interpretations. The proposed research builds on our long-term program in Bayesian (probabilistic) inversion for ocean acoustic remote sensing with six projects. (1) Inversion for seabed acoustic scattering parameters and processes. Our initial work shows that inversion of backscatter data can resolve seafloor roughness and sediment heterogeneity spectra. We propose to develop quantitative model-selection approaches to determine the relative importance of various physical scattering mechanisms and to estimate relevant scattering parameters for different seabed types, to better understand the physics of seabed scattering. (2) Estimation of laterally-variant seabed scattering parameters for naval databases or geotechnical applications such as cable laying. This  is based on sequential Bayesian inversion of novel acoustic data sets collected using a mobile system comprising an acoustic source and receiver array towed near the seabed by an autonomous underwater vehicle. (3) Extending our existing high-resolution reflectivity inversions for seabed geoacoustic parameters by including effects of shear waves, scattering, and dipping layers, with application to resolving dispersion (sound speed and attenuation frequency dependence) in marine sediments.  (4) Tomographic (2D) inversion for seabed geoacoustic properties using full-field acoustic data recorded at a fixed receiver array. A major component of quantitative nonlinear inversion in 2D involves developing new self-adaptive sparse/irregular grids to parameterize the environment in a manner consistent with the resolving power of the data to allow rigorous uncertainty estimation.  (5) Acoustic source localization and uncertainty estimation, including the effects of uncertainty in ocean environmental properties. Our initial work was in naval (passive sonar) applications, but we are moving into marine mammal studies in collaboration with JASCO Research Ltd, a leading Canadian marine-technology company. Proposed methods include a novel approach to matched-field localization with non-synchronized array systems/sub-systems, and source ranging via modal dispersion (time-frequency analysis) at a single receiver. (6) Tracking an unknown number of vocalizing marine mammals using long-term acoustic monitoring data to provide a probabilistic solution from which information on population and behaviour can be extracted.

海洋对电磁波是不透明的，但对声音是透明的;因此，声学被用于许多水下应用，例如海底遥感。 属性/过程或声源的位置（例如，潜水艇、海洋哺乳动物），具有地质、岩土工程、环境和声纳/防御应用。然而，声学遥感 需要非线性反演，定量模型选择和不确定性估计需要有意义的解释。拟议的研究建立在我们的长期计划贝叶斯（概率）反演海洋声学遥感与六个项目。 (1)海底声散射参数和过程的反演。我们的初步工作表明，反向散射数据的反演可以解决海底粗糙度和沉积物的非均匀性谱。我们建议发展定量模型选择 方法来确定各种物理散射机制的相对重要性，并估计相关的 不同海床类型的散射参数，以更好地了解海床的物理特性 散射 (2)海军数据库或岩土工程的横向变化海床散射参数的估算 应用如电缆敷设。这是基于使用移动的系统收集的新的声学数据集的顺序贝叶斯反演，所述移动系统包括在所述声学数据集附近拖曳的声源和接收器阵列。 水下机器人在海底进行了一次水下航行。 (3)扩展我们现有的高分辨率反射率反演海底地质声学参数，包括剪切波，散射和倾斜层的影响，与应用解决分散（声速和衰减频率依赖）在海洋沉积物。 (4)利用固定频率记录的全场声学数据进行海底地声特性的层析（2D）反演 接收器阵列2D定量非线性反演的一个主要组成部分涉及开发新的自适应 稀疏/不规则的网格，以符合分辨率的方式参数化环境， 数据允许严格的不确定性估计。 (5)声源定位和不确定性估计，包括海洋中不确定性的影响 环境属性。我们最初的工作是在海军（被动声纳）的应用，但我们正在进入海洋哺乳动物 与加拿大领先的海洋技术公司JASCO Research Ltd合作进行研究。提出 方法包括一种利用非同步阵列系统/子系统进行匹配场定位的新方法， 以及在单个接收器处经由模式色散（时频分析）的源测距。 (6)使用长期声学监测数据跟踪未知数量的发声海洋哺乳动物，以提供概率解决方案， 人口和行为可以被提取出来。