EAGER: Developing a temporally adaptive decomposition framework for analyzing long-term echosounder time series

科学回声测深仪是高频主动声纳系统，广泛用于研究海洋生物，特别是浮游动物和鱼类等特征最少的中营养动物。最近自主回声测深仪的部署激增，导致来自各种海洋观测平台（包括车辆和系泊设备）的回声数据泛滥。这些数据集具有巨大的潜力，可以促进我们在空间和时间尺度上对海洋生态系统的理解。然而，数据的数量和复杂性使高效和有效的分析成为一项重大挑战。本研究的目的是建立一个数据驱动的方法来自动提取回声测深仪数据的功能，从而解除仪器能力（收集大数据）和解释能力（分析大数据）之间的瓶颈。所开发的方法将加快目前劳动密集型的数据分析过程，并有助于从大型回波数据集中提取天气信息。这项研究的结果将通过开源回声分析软件包和在线教育材料作为该项目的组成部分进行传播。这项研究直接有助于提高我们的能力，以更好地了解海洋生态系统，这是至关重要的全球生物多样性和经济福祉的一个显着population of society.This研究将开发一种方法，自动发现和跟踪的低维时空结构从高维回波数据，通过调整一个国家的最先进的动态非负矩阵分解（NMF）制定。NMF是一种无监督的机器学习技术，它将复杂的数据分解为一组更小的定量描述符的线性组合，这些描述符比原始数据更易于处理和解释。该技术在许多基础研究和应用领域取得了巨大成功，包括计算机视觉，神经科学，自然语言处理和互联网零售商推荐系统。在回声分析的背景下，这些低维描述符描述了回声测深仪成像的水柱中海洋生物的垂直运动和分组活动。然而，传统的NMF不能很好地解释数据中不断变化的现象。因此，本项目的目的是开发一种方法，可以提供一个时间自适应分解，以适应长期回声测深仪数据的瞬态功能的复杂性和高的时间变化。研究人员将使用NSF的两个有线耐久阵列回声测深仪收集的数据。海洋观测站倡议（OOI）作为方法开发的试验平台。的稳定性，鲁棒性和可解释性的开发方法将进行评估，并与传统的回波分析例程进行比较。这项工作将为OOI和其他海洋观测系统的大型回波数据集的进一步机器学习和统计研究奠定基础。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Scientific echosounders are high-frequency active sonar systems used extensively to study life in the ocean, especially the least-characterized mid-trophic animals, such as zooplankton and fish. The recent surge in the deployment of autonomous echosounders has resulted in a deluge of echo data from a variety of ocean observing platforms, including vehicles and moorings. These data sets harbor great potential for advancing our understanding of marine ecosystems at spatial and temporal scales never before possible. However, the volume and complexity of the data make efficient and effective analysis a major challenge. This research is aimed at establishing a data-driven methodology to automatically extract features from echosounder data, thus unblocking this bottleneck between instrumentation capacity (to collect large data) and interpretation capability (to analyze large data). The developed method will expedite the currently labor-intensive data analysis process and help extract synoptic information from large echo data sets. Results of this research will be disseminated through open-source echo analysis software packages and online educational materials created as integrated components of this project. This research contributes directly to improving our ability to better understand the marine ecosystems, which are critical for global biodiversity and the economic well-being of a significant population of society.This research will develop a method for automated discovery and tracking of low-dimensional spatio-temporal structures from high-dimensional echo data by adapting a state-of-the-art dynamic non-negative matrix factorization (NMF) formulation. NMF is an unsupervised machine learning technique that decomposes complex data into a linear combination of a smaller set of quantitative descriptors that are more tractable and interpretable than the original data. This technique has found great success in many basic research and applied fields, including computer vision, neuroscience, natural language processing, and recommender systems for internet retailers. In the context of echo analysis, these low-dimensional descriptors characterize the vertical movements and grouping activities of marine organisms in the water column imaged by the echosounder. However, traditional NMF does not account well for a changing set of phenomena in the data. Therefore, this project aims to develop a method that can provide a temporally adaptive decomposition in order to accommodate the complexity and high temporal variability of transient features in long-term echosounder data. The researchers will use data collected by the two cabled Endurance Array echosounders in NSF?s Ocean Observatories Initiative (OOI) as a test bed for methodology development. The stability, robustness, and interpretability of the developed method will be evaluated and compared with conventional echo analysis routines. This effort will lay the foundation for further machine learning and statistical studies of large echo datasets from the OOI and other ocean observing systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.