Ocean plastic detection by satellite images? 11.04.2022

Professor Jonathan Chan, ETRO guest professor at the Vrije Universiteit Brussel, noted that the ideal sensor to detect marine plastic should possess more spectral measurement capabilities at SWIR wavelengths.

Chan is working on the Muss2 project, which is using spectral and spatial enhancement methods to generate simulated Earth orbit hyperspectral shortwave infrared images and data from the Copernicus Sentinel 2 satellite using spectral response function modelling.

Hyperspectral images taken from Earth orbit are not always available and their coverage is not as large as conventional missions, such as Landsat and Sentinel. To overcome these limitations, Chan said the Muss2 team will apply a sparse theory-based method to enhance multispectral images from the Sentinel 2 satellite. The expected results are what he described as synthetic Sentinel 2 hyperspectral images at a spatial resolution of 10m, with the same coverage as Sentinel 2 multispectral images.

‘So far, we have been able to generate such images based on Hyperion and Prisma spectral configurations, [and] quantitative assessments are promising,’ he said. ‘In addition, we apply a deep learning-based method for the spatial enhancement of Prisma images to assist in the detection of smaller objects.’

Chan added: ‘All the data inputs for the project are from open sources, including Sentinel 2, Hyperion and Prisma. The launch of Prisma in 2019 was a major milestone, and soon EnMap will be launched. These are full stretch hyperspectral images at 400-2,500nm with hundreds of spectral bands and represent the most powerful Earth orbit data source for environmental monitoring. The potential is not yet fully understood nor exploited, and scientific communities are just beginning to understand all the pre-processing protocols and data quality issues.’