Advances on Remote Sensing of Windrows as Proxies for Marine Litter Based on Sentinel-2/MSI Datasets.

An increasing interest in the development of remote sensing techniques for marine litter observation and monitoring has appeared in recent years. In 2020, the European Space Agency (ESA) launched the Discovery Campaign on Remote Sensing of Plastic Marine Litter, funding a total of 26 initiatives across a wide spectrum of areas. The “Windrows As Proxies” project (WASP), included in the initiative, aims to prototype an operational processor capable of identifying filaments of floating marine debris using Copernicus Sentinel-2/MSI images, with a high probability of containing marine litter, i.e., using proxies. The following work presents the initial algorithm design of WASP processor, the development of a novel WASP Spectral Index (WSI) and the application of a deterministic classifier to identify them. Results show that WSI is a very robust index to perform such task, technically simpler than existing alternatives and physics-driven, opening the path towards an operational remote sensing of marine litter.