UAV-Based Environmental Monitoring of Rip-Current Indicators Using Wavelet-Derived Texture Features
2026-08-03 • Computer Vision and Pattern Recognition
Computer Vision and Pattern Recognition
AI summaryⓘ
The authors studied how to better detect dangerous rip currents at beaches using pictures from drones. Rip currents are tricky to spot because they only cause subtle changes in how waves and foam look. They combined wavelet-based texture features with deep learning methods to improve detection accuracy. Their new approach worked better than just using regular RGB images and helped the model focus on the right visual clues. This could help make drone-based safety tools more reliable for beach monitoring.
Rip currentsUnmanned aerial vehicles (UAVs)RGB imageryWavelet transformTexture featuresDeep learningConvolutional neural networksImage classificationObject detectionExplainable AI
Authors
Yonatan Ben Avraham, Baruch Binyaminov, Yehudit Aperstein
Abstract
Rip currents are recurrent coastal natural hazards that threaten beachgoers and create operational challenges for lifeguards and coastal managers. Reliable monitoring from standard RGB (red-green-blue) imagery acquired by unmanned aerial vehicles (UAVs) remains difficult because hazardous channels often appear as subtle gaps in breaking waves, foam texture, or sediment patterns, and these signatures are affected by illumination, sea state, and environmental noise. This study presents a physically informed coastal environmental monitoring workflow for detecting visually expressed rip-current indicators that integrates wavelet-derived spatial-frequency texture features with deep learning. We evaluate multiple strategies for incorporating Discrete Wavelet Transform features into convolutional architectures, from computationally efficient channel replacement to dual-stream fusion with attention mechanisms. Performance is assessed against a standard RGB baseline using a task specific convolutional neural network for image-level presence classification and a YOLOv8 model for object-level localization. Under the evaluated dataset conditions, integrating wavelet derived texture features improves performance over RGB-only models. The dual-stream architecture achieves the strongest classification performance, exceeding 95% accuracy with high recall, while channel replacement is most effective for YOLOv8 object detection, reaching 94% mAP@50 for localization. Explainable artificial intelligence analyses provide qualitative evidence that the models attend to visually plausible wave-gap regions associated with rip currents. These results suggest that under the conditions of the evaluated dataset, physically informed wavelet integration may support UAV-based decision-support tools for interpretable beach-safety risk mitigation.