Sea ice classification of TerraSAR-X ScanSAR images for the MOSAiC expedition incorporating per-class incidence angle dependency of image texture
<p>We provide sea ice classification maps of a sub-weekly time series of single (horizontal–horizontal, HH) polarization X-band TerraSAR-X scanning synthetic aperture radar (TSX SC) images from November 2019 to March 2020, covering the Multidisciplinary drifting Observatory for the Study of Ar...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2023-03-01
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| Series: | The Cryosphere |
| Online Access: | https://tc.copernicus.org/articles/17/1279/2023/tc-17-1279-2023.pdf |
| _version_ | 1797869370109591552 |
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| author | W. Guo P. Itkin S. Singha S. Singha A. P. Doulgeris M. Johansson G. Spreen |
| author_facet | W. Guo P. Itkin S. Singha S. Singha A. P. Doulgeris M. Johansson G. Spreen |
| author_sort | W. Guo |
| collection | DOAJ |
| description | <p>We provide sea ice classification maps of a sub-weekly time series of single (horizontal–horizontal, HH) polarization X-band TerraSAR-X scanning synthetic aperture radar (TSX SC) images from November 2019 to March 2020, covering the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. This classified time series benefits from the wide spatial coverage and relatively high spatial resolution of TSX SC data and is a useful basic dataset for future MOSAiC studies on physical sea ice processes and ocean and climate modeling. Sea ice is classified into leads, young ice with different backscatter intensities, and first-year ice (FYI) or multiyear ice (MYI) with different degrees of deformation. We establish the per-class incidence angle (IA) dependencies of TSX SC intensities and gray-level co-occurrence matrix (GLCM) textures and use a classifier that corrects for the class-specific decreasing backscatter with increasing IAs, with both HH intensities and textures as input features. Optimal parameters for texture calculation are derived to achieve good class separation while maintaining maximum spatial detail and minimizing textural collinearity. Class probabilities yielded by the classifier are adjusted by Markov random field contextual smoothing to produce classification results. The texture-based classification process yields an average overall accuracy of 83.70 % and good correspondence to geometric ice surface roughness derived from in situ ice thickness measurements (correspondence consistently close to or higher than 80 %). A positive logarithmic relationship is found between geometric ice surface roughness and TSX SC HH backscatter intensity, similar to previous C- and L-band studies. Areal fractions of classes representing ice openings (leads and young ice) show prominent increases in middle to late November 2019 and March 2020, corresponding well to ice-opening time series derived from in situ data in this study and those derived from satellite synthetic aperture radar (SAR) and optical data in other MOSAiC studies.</p> |
| first_indexed | 2024-04-10T00:11:36Z |
| format | Article |
| id | doaj.art-e2a9adbf5fb548b196c3feca1c700044 |
| institution | Directory Open Access Journal |
| issn | 1994-0416 1994-0424 |
| language | English |
| last_indexed | 2024-04-10T00:11:36Z |
| publishDate | 2023-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | The Cryosphere |
| spelling | doaj.art-e2a9adbf5fb548b196c3feca1c7000442023-03-16T09:22:44ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242023-03-01171279129710.5194/tc-17-1279-2023Sea ice classification of TerraSAR-X ScanSAR images for the MOSAiC expedition incorporating per-class incidence angle dependency of image textureW. Guo0P. Itkin1S. Singha2S. Singha3A. P. Doulgeris4M. Johansson5G. Spreen6Department of Physics and Technology, UiT The Arctic University of Norway, Tromsø, NorwayDepartment of Physics and Technology, UiT The Arctic University of Norway, Tromsø, NorwayRemote Sensing Technology Institute (IMF), German Aerospace Center (DLR), Bremen, Germanycurrently at: National Center for Climate Research (NCKF), Danish Meteorological Institute (DMI), Copenhagen, DenmarkDepartment of Physics and Technology, UiT The Arctic University of Norway, Tromsø, NorwayDepartment of Physics and Technology, UiT The Arctic University of Norway, Tromsø, NorwayInstitute of Environmental Physics, University of Bremen, Bremen, Germany<p>We provide sea ice classification maps of a sub-weekly time series of single (horizontal–horizontal, HH) polarization X-band TerraSAR-X scanning synthetic aperture radar (TSX SC) images from November 2019 to March 2020, covering the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. This classified time series benefits from the wide spatial coverage and relatively high spatial resolution of TSX SC data and is a useful basic dataset for future MOSAiC studies on physical sea ice processes and ocean and climate modeling. Sea ice is classified into leads, young ice with different backscatter intensities, and first-year ice (FYI) or multiyear ice (MYI) with different degrees of deformation. We establish the per-class incidence angle (IA) dependencies of TSX SC intensities and gray-level co-occurrence matrix (GLCM) textures and use a classifier that corrects for the class-specific decreasing backscatter with increasing IAs, with both HH intensities and textures as input features. Optimal parameters for texture calculation are derived to achieve good class separation while maintaining maximum spatial detail and minimizing textural collinearity. Class probabilities yielded by the classifier are adjusted by Markov random field contextual smoothing to produce classification results. The texture-based classification process yields an average overall accuracy of 83.70 % and good correspondence to geometric ice surface roughness derived from in situ ice thickness measurements (correspondence consistently close to or higher than 80 %). A positive logarithmic relationship is found between geometric ice surface roughness and TSX SC HH backscatter intensity, similar to previous C- and L-band studies. Areal fractions of classes representing ice openings (leads and young ice) show prominent increases in middle to late November 2019 and March 2020, corresponding well to ice-opening time series derived from in situ data in this study and those derived from satellite synthetic aperture radar (SAR) and optical data in other MOSAiC studies.</p>https://tc.copernicus.org/articles/17/1279/2023/tc-17-1279-2023.pdf |
| spellingShingle | W. Guo P. Itkin S. Singha S. Singha A. P. Doulgeris M. Johansson G. Spreen Sea ice classification of TerraSAR-X ScanSAR images for the MOSAiC expedition incorporating per-class incidence angle dependency of image texture The Cryosphere |
| title | Sea ice classification of TerraSAR-X ScanSAR images for the MOSAiC expedition incorporating per-class incidence angle dependency of image texture |
| title_full | Sea ice classification of TerraSAR-X ScanSAR images for the MOSAiC expedition incorporating per-class incidence angle dependency of image texture |
| title_fullStr | Sea ice classification of TerraSAR-X ScanSAR images for the MOSAiC expedition incorporating per-class incidence angle dependency of image texture |
| title_full_unstemmed | Sea ice classification of TerraSAR-X ScanSAR images for the MOSAiC expedition incorporating per-class incidence angle dependency of image texture |
| title_short | Sea ice classification of TerraSAR-X ScanSAR images for the MOSAiC expedition incorporating per-class incidence angle dependency of image texture |
| title_sort | sea ice classification of terrasar x scansar images for the mosaic expedition incorporating per class incidence angle dependency of image texture |
| url | https://tc.copernicus.org/articles/17/1279/2023/tc-17-1279-2023.pdf |
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