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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=649502
• 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. **

海洋对电磁波不透明，但对声音透明；因此，声学可用于许多水下应用，例如海底*特性/过程或声源位置（例如潜艇、海洋哺乳动物）的遥感，以及地质、岩土、环境和声纳/国防应用。然而，声学遥感*需要非线性反演，并需要定量模型选择和不确定性估计才能进行有意义的解释。拟议的研究建立在我们的海洋声学遥感贝叶斯（概率）反演长期计划的基础上，共有六个项目。***(1) 海底声学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析海底粗糙度和沉积物异质性光谱。我们建议开发定量模型选择*方法来确定各种物理散射机制的相对重要性，并估计不同海底类型的相关*散射参数，以更好地理解海底*散射的物理原理。 ***(2) 估计海军数据库或岩土工程*应用（例如电缆敷设）的横向变化海底散射参数。这是基于使用移动系统收集的新颖声学数据集的顺序贝叶斯反演，该移动系统包括由自主水下航行器拖曳在海底附近的声源和接收器阵列。 ***(3) 通过考虑剪切波、散射和倾角层的影响，扩展我们现有的海底地声参数高分辨率反射率反演，并应用于解决海洋沉积物中的色散（声速和衰减频率依赖性）。 ***(4) 使用固定*接收器阵列记录的全场声学数据对海底地声特性进行层析 (2D) 反演。二维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/不规则网格，以与*数据的分辨率一致的方式参数化环境，以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*环境特性的不确定性影响。我们最初的工作是在海军（被动声纳）应用中，但我们正在与加拿大领先的海洋技术公司 JASCO Research Ltd 合作进入海洋哺乳动物*研究。提议的*方法包括一种使用非同步阵列系统/子系统进行匹配场定位的新颖方法，*以及通过单个接收器上的模态色散（时频分析）进行源测距。 ***(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，从中提取有关*种群和行为的信息。 **