Investigating the Influence of Variable Freshwater Ice Types on Passive and Active Microwave Observations
Dual-polarized airborne passive microwave (PM) brightness temperatures (Tb) at 6.9 GHz H/V, 19 GHz H/V and 37 GHz H/V and spaceborne active microwave (AM) X-band (9.65 GHz VV, VH) backscatter (σ0) are observed coincident to in situ snow and lake-ice measurements collected over two lakes near Inuvik,...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2017-12-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/9/12/1242 |
| _version_ | 1818959873654652928 |
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| author | Grant E. Gunn Claude R. Duguay Chris Derksen David A. Clausi Peter Toose |
| author_facet | Grant E. Gunn Claude R. Duguay Chris Derksen David A. Clausi Peter Toose |
| author_sort | Grant E. Gunn |
| collection | DOAJ |
| description | Dual-polarized airborne passive microwave (PM) brightness temperatures (Tb) at 6.9 GHz H/V, 19 GHz H/V and 37 GHz H/V and spaceborne active microwave (AM) X-band (9.65 GHz VV, VH) backscatter (σ0) are observed coincident to in situ snow and lake-ice measurements collected over two lakes near Inuvik, Canada. Lake-ice thickness is found to be positively correlated with 19 GHz V emission (R = 0.67) and negatively with 19 GHz H emission (R = −0.79), indicating surface ice conditions influence microwave interaction. Lake ice types are delineated from TerraSAR-X synthetic aperture radar (SAR) images using the iterative region growing with semantics (IRGS) segmentation algorithm implemented in the MAGIC (MAp Guided Ice Classification) system. The spatial extent of derived ice type classes correspond well to in situ observations. The overall magnitude of emission at 19 GHz H and X-band VH σ0 increase with the scattering potential of associated ice types (grey/rafted ice). Transects of 6.9 GHz PM and 19 GHz PM exhibit positive relationships with VH σ0 over freshwater lake ice, with the greatest R coefficients at H-pol (R = 0.64, 0.46). Conversely, 6.9 GHz Tb and 19 GHz Tb exhibit negative R coefficients in regions of brackish water due to tubular bubble and brine inclusions in the ice. This study identifies congruency between PM and AM scattering mechanisms over lake ice for the purpose of identifying the influence of ice types on overall microwave interaction within the lake-ice system. |
| first_indexed | 2024-12-20T11:48:34Z |
| format | Article |
| id | doaj.art-b8b582516ab64df2810b4932fc66f380 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-12-20T11:48:34Z |
| publishDate | 2017-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-b8b582516ab64df2810b4932fc66f3802022-12-21T19:41:49ZengMDPI AGRemote Sensing2072-42922017-12-01912124210.3390/rs9121242rs9121242Investigating the Influence of Variable Freshwater Ice Types on Passive and Active Microwave ObservationsGrant E. Gunn0Claude R. Duguay1Chris Derksen2David A. Clausi3Peter Toose4Department of Geography, Environment and Spatial Sciences, Michigan State University, East Lansing, MI 48824, USADepartment of Geography and Environmental Management, and the Interdisciplinary Centre on Climate Change, University of Waterloo, Waterloo, ON N2L 3G1, CanadaClimate Research Division, Environment and Climate Change Canada, Toronto, ON M3H 5T4, CanadaDepartment of Systems Design Engineering and Vision and Image Processing (VIP) Research Group, University of Waterloo, Waterloo, ON N2L 3G1, CanadaClimate Research Division, Environment and Climate Change Canada, Toronto, ON M3H 5T4, CanadaDual-polarized airborne passive microwave (PM) brightness temperatures (Tb) at 6.9 GHz H/V, 19 GHz H/V and 37 GHz H/V and spaceborne active microwave (AM) X-band (9.65 GHz VV, VH) backscatter (σ0) are observed coincident to in situ snow and lake-ice measurements collected over two lakes near Inuvik, Canada. Lake-ice thickness is found to be positively correlated with 19 GHz V emission (R = 0.67) and negatively with 19 GHz H emission (R = −0.79), indicating surface ice conditions influence microwave interaction. Lake ice types are delineated from TerraSAR-X synthetic aperture radar (SAR) images using the iterative region growing with semantics (IRGS) segmentation algorithm implemented in the MAGIC (MAp Guided Ice Classification) system. The spatial extent of derived ice type classes correspond well to in situ observations. The overall magnitude of emission at 19 GHz H and X-band VH σ0 increase with the scattering potential of associated ice types (grey/rafted ice). Transects of 6.9 GHz PM and 19 GHz PM exhibit positive relationships with VH σ0 over freshwater lake ice, with the greatest R coefficients at H-pol (R = 0.64, 0.46). Conversely, 6.9 GHz Tb and 19 GHz Tb exhibit negative R coefficients in regions of brackish water due to tubular bubble and brine inclusions in the ice. This study identifies congruency between PM and AM scattering mechanisms over lake ice for the purpose of identifying the influence of ice types on overall microwave interaction within the lake-ice system.https://www.mdpi.com/2072-4292/9/12/1242active microwavepassive microwavesynthetic aperture radarlake iceice typesX-bandgrey icerafted iceTerraSAR-X |
| spellingShingle | Grant E. Gunn Claude R. Duguay Chris Derksen David A. Clausi Peter Toose Investigating the Influence of Variable Freshwater Ice Types on Passive and Active Microwave Observations Remote Sensing active microwave passive microwave synthetic aperture radar lake ice ice types X-band grey ice rafted ice TerraSAR-X |
| title | Investigating the Influence of Variable Freshwater Ice Types on Passive and Active Microwave Observations |
| title_full | Investigating the Influence of Variable Freshwater Ice Types on Passive and Active Microwave Observations |
| title_fullStr | Investigating the Influence of Variable Freshwater Ice Types on Passive and Active Microwave Observations |
| title_full_unstemmed | Investigating the Influence of Variable Freshwater Ice Types on Passive and Active Microwave Observations |
| title_short | Investigating the Influence of Variable Freshwater Ice Types on Passive and Active Microwave Observations |
| title_sort | investigating the influence of variable freshwater ice types on passive and active microwave observations |
| topic | active microwave passive microwave synthetic aperture radar lake ice ice types X-band grey ice rafted ice TerraSAR-X |
| url | https://www.mdpi.com/2072-4292/9/12/1242 |
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