Global 1-km Coastal Bathymetry from Sentinel-2 Wave Inversion using the Satellite-to-Shores (S2hores) Toolbox

Area of Science:

• Geosciences
• Remote Sensing
• Oceanography

Background:

• Coastal bathymetry data is crucial for monitoring, hazard assessment, and modeling.
• Existing bathymetry data is often scarce, outdated, or lacks global coverage.

Purpose of the Study:

• To address the scarcity of reliable coastal bathymetry by creating a global dataset.
• To introduce the Satellites to Shores (S2Shores) initiative and its methodology.

Main Methods:

• Utilized a wave-based inversion approach on over one million Sentinel-2 satellite images.
• Developed an open-source pipeline integrating compositing, blending, and quality control for large-scale processing.
• Employed high-performance computing for efficient data generation.

Main Results:

• Generated a global coastal bathymetry dataset at 1-km spatial resolution.
• Achieved root mean square errors of 2-5 m and R² > 0.7 for depths between 10-40 m.
• Demonstrated effective retrieval depths up to 60 m in energetic coastal areas.

Conclusions:

• The S2Shores dataset provides a reproducible, open-source global resource for coastal research.
• This dataset significantly enhances capabilities for coastal monitoring, climate studies, and operational forecasting.
• The methodology offers a scalable solution for generating vital nearshore bathymetry data.