Thank you Moritz for your support!! Roberta
2018-08-13 12:06 GMT+02:00 Moritz Lennert <mlenn...@club.worldonline.be>: > Great work, Roberta ! > > Thanks for these two very useful modules ! > > > Moritz > > On 13/08/18 10:20, Roberta Fagandini wrote: > >> Hi all! >> I'm Roberta Fagandini and this is the final report of my GSoC project. >> >> The title of the project is "GRASS GIS module for Sentinel-2 cloud and >> shadow detection". It adds new tools for the processing of Sentinel 2 >> images to GRASS GIS software (Organization: OSGeo). >> >> *Abstract:* >> Optical sensors are unable to penetrate clouds leading to related >> anomalous reflectance values. Unlike Landsat images, Sentinel 2 datasets do >> not include thermal and Quality Assessment bands that simplify the >> detection of clouds avoiding erroneous classification. At the same time, >> also clouds shadows on the ground lead to anomalous reflectance values >> which have to be taken into account during the image processing. >> The project creates a specific module for GRASS GIS application >> (i.sentinel.mask) which implements an automatic procedure for clouds and >> shadows detection for Sentinel 2 images. The procedure is based on an >> algorithm, developed within my PhD research, which allows to automatically >> identify clouds and their shadows applying some rules on reflectance values >> (values thresholds, comparisons between bands, etc.). These have been >> defined starting from rules found in literature and conveniently refined. >> In order to increase the accuracy of the final results, a control check is >> implemented. Clouds and shadows are spatially intersected in order to >> remove misclassified areas. The final outputs are two different vector maps >> (OGR standard formats), one for clouds and one for shadows. >> To run i.sentinel.mask, the bands of the desired Sentinel 2 images have >> to be imported and the atmospheric correction has to be applied. >> In order to make the data preparation easier, another GRASS >> GISaddonmodule has been developed within the GSoC project. >> i.sentinel.preprocis a module for the preprocessing of Sentinel 2 images >> (Level-1C Single Tile product) which wraps the import and the atmospheric >> correction using respectively two existing GRASS GIS modules, >> i.sentinel.import and i.atcorr. >> >> *The state of the art before the project:* >> Before this GSoC 2018 project, no modules for the detection of clouds and >> shadows were available for Sentinel 2 images. Only a specific module for >> Landsat automatic cloud coverage assessment was available within GRASS GIS >> (i.landsat.acca) while regarding shadows, no specific module was available. >> Moreover, performing the atmospheric correction was a bit complicated >> especially for unexperiencedusers who have to process one band at a time >> and provide all input parameters manually. >> >> *The added value that the project brought to GRASS GIS:* >> Now a specific module for clouds and shadows detection, >> i.sentinel.mask,is available in GRASS GIS. >> Moreover, i.sentinel.preprocprovides a simplified module which allows >> importing images and performing the atmospheric correction avoiding users >> to supply all the required input parameters manually. The module should >> help users in preparing data to use as input for i.sentinel.mask. In fact, >> it makes especially the atmospheric correction procedure easier and faster >> because it allows performing atmospheric correction of all bands of a >> Sentinel 2 scene with a single process and it retrieves most of the >> required input parameters from the image itself. Moreover, one of the >> possible output of i.sentinel.preprocis a text file to be used as input for >> i.sentinel.mask. >> >> *Follow up:* >> Both i.sentinel.mask and i.sentinel.preprocare complete and working >> modules which can be easily installed with g.extension from the official >> GRASS GIS SVN repository. >> Obviously, they can be improved therefore the next steps could be: >> >> * Implementation of other existing algorithms of clouds and shadows >> detection (i.sentinel.mask) >> * Implementation of a new download procedure avoiding dependencies >> (i.sentinel.preproc) >> * Integration of the Topographic Correction (i.sentinel.preproc) >> >> NOTE: Implementation of other existing algorithms of clouds and shadows >> detection was one of the possible goals of the GSoC project but the >> codingand debuggingof some parts of the twoaddonsrequired more time than >> expected. >> >> *Permanent links:* >> * >> * >> /Code developed during the GSoC coding period: / >> https://github.com/RobiFag/GRASS_clouds_and_shadows < >> https://github.com/RobiFag/GRASS_clouds_and_shadows> >> >> /Codes on the official GRASS GIS SVN repository:/ >> https://trac.osgeo.org/grass/browser/grass-addons/grass7/ima >> gery/i.sentinel.mask <https://trac.osgeo.org/grass/ >> browser/grass-addons/grass7/imagery/i.sentinel.mask> >> https://trac.osgeo.org/grass/browser/grass-addons/grass7/ima >> gery/i.sentinel.preproc <https://trac.osgeo.org/grass/ >> browser/grass-addons/grass7/imagery/i.sentinel.preproc> >> >> /Documentation:/ >> https://grass.osgeo.org/grass74/manuals/addons/i.sentinel.mask.html < >> https://grass.osgeo.org/grass74/manuals/addons/i.sentinel.mask.html> >> https://grass.osgeo.org/grass74/manuals/addons/i.sentinel.preproc.html < >> https://grass.osgeo.org/grass74/manuals/addons/i.sentinel.preproc.html> >> >> /Weekly reports: / >> https://trac.osgeo.org/grass/wiki/GSoC/2018/CloudsAndShadowsDetection < >> https://trac.osgeo.org/grass/wiki/GSoC/2018/CloudsAndShadowsDetection> >> >> /Images to showcase the project:/ >> i.sentinel.mask >> https://raw.githubusercontent.com/RobiFag/GRASS_clouds_and_s >> hadows/master/images/i_sentinel_mask_GWF.png < >> https://raw.githubusercontent.com/RobiFag/GRASS_clouds_and_ >> shadows/master/images/i_sentinel_mask_GWF.png> >> https://raw.githubusercontent.com/RobiFag/GRASS_clouds_and_s >> hadows/master/images/i_sentinel_mask_CD.png < >> https://raw.githubusercontent.com/RobiFag/GRASS_clouds_and_ >> shadows/master/images/i_sentinel_mask_CD.png> >> https://raw.githubusercontent.com/RobiFag/GRASS_clouds_and_s >> hadows/master/images/i_sentinel_mask_SD.png < >> https://raw.githubusercontent.com/RobiFag/GRASS_clouds_and_ >> shadows/master/images/i_sentinel_mask_SD.png> >> https://raw.githubusercontent.com/RobiFag/GRASS_clouds_and_s >> hadows/master/images/i_sentinel_mask_CS.png < >> https://raw.githubusercontent.com/RobiFag/GRASS_clouds_and_ >> shadows/master/images/i_sentinel_mask_CS.png> >> https://raw.githubusercontent.com/RobiFag/GRASS_clouds_and_s >> hadows/master/images/i_sentinel_mask_ES.png < >> https://raw.githubusercontent.com/RobiFag/GRASS_clouds_and_ >> shadows/master/images/i_sentinel_mask_ES.png> >> i.sentinel.preproc >> https://raw.githubusercontent.com/RobiFag/GRASS_clouds_and_s >> hadows/master/images/i_sentinel_preproc_GWF.png < >> https://raw.githubusercontent.com/RobiFag/GRASS_clouds_and_ >> shadows/master/images/i_sentinel_preproc_GWF.png> >> >> >> Kind regards, >> Roberta >> >> > >
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