SkySea: Connecting Satellite, UAV and Underwater Imagery for Benthic Habitat Mapping

Satellite imagery, UAV imagery, and geo-referenced underwater photo transects (from the surface) are different methods used in marine monitoring and benthic habitat mapping applications to collect observations at different spatial scales. There are however challenges in linking them all together to provide fine-grained mapping and analysis for underwater, benthic habitats with complex geometric and ecological properties. We propose a novel framework called SkySea that offers users access to aligned observational data at multiple spatial scales. SkySea can integrate satellite images (e.g., from SENTINEL-2 at 10m resolution), UAV images (<5cm ground sampling distance), detailed underwater images, 3D reconstruction of the seafloor/benthos from underwater images, and make the data available through a commonly used user interface, such as QGIS(1). Initial evaluation indicates that the spatial overlay achieves sub-meter-level accuracy, while the underwater 3D reconstruction reaches an average relative error of less than 10% for size estimation with reference objects. We believe that this is a novel and innovative framework to achieve a seamless connection across an enormous gap of scales from satellite images, regional UAV images, local underwater images and local 3D reconstruction of the underwater environment, for benthic habitat mapping. It enables marine biologists to perform survey planning, species mapping, and model validation tasks in an integrated pipeline.