The DESIS Hyperspectral Sensor on the International Space Station: A Novel, Automatically Taskable Platform for Monitoring Ocean Plastics and Understanding Ocean Currents

One earth imaging platform that has the potential to open doors for atmospheric and oceanic knowledge is the International Space Station (ISS). The ISS is the home to the earth looking DESIS sensor (DLR Earth Sensing Imaging Spectrometer), VNIR hyperspectral sensor. It has a 30m ground sample distance, a 30km swath width, and it is taskable between roughly 50 degrees north and south. The ISS orbit allows for more frequent imaging in the tropics, meaning there are multiple days in a row where collects of the same area are possible. This orbital pattern creates an opportunity for more cloud free imagery. As many meteorologists want to study clouds, the problem of studying large amounts of oceanic plastics requires clear imagery. There are over 80,000 tonnes of plastic in the Great Pacific Garbage Patch alone not to mention other areas in the Caribbean, South Pacific, Indian and Atlantic Oceans as well as near shore reefs and atolls. Because of the size of the world's oceans, tasking imaging sensors to locate plastics is nigh on impossible. Commercial Satellite imagery has too small of a foot print and not enough temporal coverage to study this problem. Landsat and Sentinel-2 imagery have better spatial and temporal coverage, but still lack the spectral resolution to extract plastics and other debris (oil, rubber, metal, cement, nets etc.) from water. In this talk three main discoveries will be discussed:

1) Identifying plastics from a space based system with hyperspectral imagery on the ISS, and showing intelligent tasking can guide locating the worst of the garbage patch zones

2)Rapid on-board processing from the MUSES system can downlink plastics locations within an hour, so mitigation of plastics in the dynamic environment of the ocean can be possible

3) By being able to track certain plastic patches over time, there will be an opportunity to understand surface and subsurface currents, how plastics and other debris move in oceanic and coastal environments.

These components all come together to provide new methods of not only understanding an environmental catastrophe, but also how ocean processes move these kinds of materials and debris. By using the ISS, and DESIS and MUSES as R&D tools for this problem, better techniques, instruments, and simply raising our knowledge of this issue can make mitigation, planning and better practices with oceanic plastics/debris possible.