用自动检测方法分析三百万条鱼类声学数据,精准识别异常行为。
Unsupervised anomaly detection in large-scale estuarine acoustic telemetry data
- 基于自编码神经网络构建自动化异常检测模型
- 召回率高且无误判正常行为,关键优于其他模型
- 适合大尺度水生动物追踪研究者使用
声学遥测数据对理解水生动物行为与迁徙至关重要。然而,包含数百万条记录的大规模数据集常含异常移动,传统人工或基础统计方法耗时且漏检率高。本研究针对南非布迪河50条标记大鳞鳕的长期数据,利用2016至2021年间部署在16个接收器上的阵列,收集超过三百万条个体数据点。提出完整的预处理、重采样、特征工程、数据划分及模型选择流程。在对比模型中,神经网络自编码器(NN-AE)表现最优,结合所提阈值查找算法,实现高召回率且无假正常(即无异常被误判为正常),确保不遗漏真实异常。而其他模型假正常比例超0.9,表明多数异常未被发现,严重干扰行为解读。尽管NN-AE可靠,但在正常模式渐变偏离时仍难准确学习。
原文摘要 · Abstract (English)
Acoustic telemetry data plays a vital role in understanding the behaviour and movement of aquatic animals. However, these datasets, which often consist of millions of individual data points, frequently contain anomalous movements that pose significant challenges. Traditionally, anomalous movements are identified either manually or through basic statistical methods, approaches that are time-consuming and prone to high rates of unidentified anomalies in large datasets. This study focuses on the development of automated classifiers for a large telemetry dataset comprising detections from fifty acoustically tagged dusky kob monitored in the Breede Estuary, South Africa. Using an array of 16 acoustic receivers deployed throughout the estuary between 2016 and 2021, we collected over three million individual data points. We present detailed guidelines for data pre-processing, resampling strategies, labelling process, feature engineering, data splitting methodologies, and the selection and interpretation of machine learning and deep learning models for anomaly detection. Among the evaluated models, neural networks autoencoder (NN-AE) demonstrated superior performance, aided by our proposed threshold-finding algorithm. NN-AE achieved a high recall with no false normal (i.e., no misclassifications of anomalous movements as normal patterns), a critical factor in ensuring that no true anomalies are overlooked. In contrast, other models exhibited false normal fractions exceeding 0.9, indicating they failed to detect the majority of true anomalies; a significant limitation for telemetry studies where undetected anomalies can distort interpretations of movement patterns. While the NN-AE's performance highlights its reliability and robustness in detecting anomalies, it faced challenges in accurately learning normal movement patterns when these patterns gradually deviated from anomalous ones.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。