[M-IS21] Understanding plastic pollution: The reality and countermeasures

[MIS21-01] Satellite-based marine debris monitoring strategy

★Invited Papers

*Yukihiro Takahashi¹, Ahmad Shaqeer Mohamed Thaheer¹, Ye Min Htay¹, Shinichiro Kako² (1.Department of Cosmosciences, Graduate School of Science, Hokkaido University, 2.Graduate School of Science and Engineering, Kagoshima University)

Keywords:Matine debris, plastics, micro-satellite, spectral reflection

It is not easy to figure out the routes that marine debris, including plastic waste washed up from rivers, takes as it moves around the ocean, is washed up on the shore, and is returned to the sea before finally accumulating in a particular location. Drones can conduct detailed surveys of beaches within a range of around 100 meters, but it is difficult to measure in bays that are not easily accessible due to the terrain, or in wide areas such as the entire coastline of a country. On the other hand, satellites are a powerful tool that can monitor wide areas in a short time, but they have limitations in terms of spatial resolution, and it is difficult to distinguish the type and size of the debris. In addition, if the satellite's visiting cycle is long, it is not possible to track the movement of debris in the ocean every moment using conventional satellites alone. We are working on a plan to develop and operate a satellite based on detailed analysis of the spectral reflectance of marine debris collected from beaches and other locations, and to determine the most suitable wavelength combinations for identifying the type of debris. Because we own and operate our micro-satellite, we can change the viewing direction of the camera freely for our own purposes, and as a result, it is possible to track a specific target every day, even with a single satellite. However, the ground resolution of the spectral camera mounted on the satellite is limited to 3-5m at best, so it is not possible to resolve and recognize individual pieces of trash. For this reason, we observe as a composite of the spectral reflection of multiple objects and estimate the proportion of each material. By applying this advanced satellite technology, we hope to clarify the dynamics of marine debris through agile observation while reducing costs to a fraction of those of conventional satellites.