Snowmelt retrieval algorithm for the Antarctic Peninsula using SAR imageries
Abstract The classification of Synthetic Aperture Radar (SAR) images by knowledge-based algorithms with elevation and backscatter thresholds were used in several studies to detect the Wet Snow Radar Zone (WSZ) in the Antarctic Peninsula. To identify it more accurately based on its seasonal variation...
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Academia Brasileira de Ciências
2022-03-01
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| Series: | Anais da Academia Brasileira de Ciências |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652022000201103&tlng=en |
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| author | CLAUDIO W. MENDES JR JORGE ARIGONY NETO FERNANDO L. HILLEBRAND MARCOS W.D. DE FREITAS JULIANA COSTI JEFFERSON C. SIMÕES |
| author_facet | CLAUDIO W. MENDES JR JORGE ARIGONY NETO FERNANDO L. HILLEBRAND MARCOS W.D. DE FREITAS JULIANA COSTI JEFFERSON C. SIMÕES |
| author_sort | CLAUDIO W. MENDES JR |
| collection | DOAJ |
| description | Abstract The classification of Synthetic Aperture Radar (SAR) images by knowledge-based algorithms with elevation and backscatter thresholds were used in several studies to detect the Wet Snow Radar Zone (WSZ) in the Antarctic Peninsula. To identify it more accurately based on its seasonal variations, this study proposed the additional use of a threshold in synthetic images, created by rationing summer and winter sigma linear images. In our algorithm we used the following thresholds to detect the WSZ in Envisat ASAR imageries, using the Radarsat Antarctic Map Digital Elevation Model as ancillary data: i) -25 dB < s0 < -14 dB; ii) slinear summer / slinear winter < 0.4; iii) elevation H < 1,200 m for northern tip and H < 800 m for southern tip of the Antarctic Peninsula. The classified images were post-processed by a focal majority 5 x 5 filter and superimposed by an image of rock outcrops derived from the Antarctic Digital Database. The ratio image threshold allowed discriminating the WSZ from the Dry Snow Radar Zone and radar shadows, as well as transitional areas between this glacier zone and the Frozen Percolation Radar Zone, which would be classified incorrectly if we used only elevation and backscatter thresholds. |
| first_indexed | 2024-12-13T20:28:54Z |
| format | Article |
| id | doaj.art-b5c7c3b38daa473698f426451b8f2088 |
| institution | Directory Open Access Journal |
| issn | 1678-2690 |
| language | English |
| last_indexed | 2024-12-13T20:28:54Z |
| publishDate | 2022-03-01 |
| publisher | Academia Brasileira de Ciências |
| record_format | Article |
| series | Anais da Academia Brasileira de Ciências |
| spelling | doaj.art-b5c7c3b38daa473698f426451b8f20882022-12-21T23:32:29ZengAcademia Brasileira de CiênciasAnais da Academia Brasileira de Ciências1678-26902022-03-0194suppl 110.1590/0001-3765202220210217Snowmelt retrieval algorithm for the Antarctic Peninsula using SAR imageriesCLAUDIO W. MENDES JRhttps://orcid.org/0000-0003-1745-348XJORGE ARIGONY NETOhttps://orcid.org/0000-0003-4848-2064FERNANDO L. HILLEBRANDhttps://orcid.org/0000-0002-0182-8526MARCOS W.D. DE FREITAShttps://orcid.org/0000-0001-9879-2584JULIANA COSTIhttps://orcid.org/0000-0001-6220-2343JEFFERSON C. SIMÕEShttps://orcid.org/0000-0001-5555-3401Abstract The classification of Synthetic Aperture Radar (SAR) images by knowledge-based algorithms with elevation and backscatter thresholds were used in several studies to detect the Wet Snow Radar Zone (WSZ) in the Antarctic Peninsula. To identify it more accurately based on its seasonal variations, this study proposed the additional use of a threshold in synthetic images, created by rationing summer and winter sigma linear images. In our algorithm we used the following thresholds to detect the WSZ in Envisat ASAR imageries, using the Radarsat Antarctic Map Digital Elevation Model as ancillary data: i) -25 dB < s0 < -14 dB; ii) slinear summer / slinear winter < 0.4; iii) elevation H < 1,200 m for northern tip and H < 800 m for southern tip of the Antarctic Peninsula. The classified images were post-processed by a focal majority 5 x 5 filter and superimposed by an image of rock outcrops derived from the Antarctic Digital Database. The ratio image threshold allowed discriminating the WSZ from the Dry Snow Radar Zone and radar shadows, as well as transitional areas between this glacier zone and the Frozen Percolation Radar Zone, which would be classified incorrectly if we used only elevation and backscatter thresholds.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652022000201103&tlng=enAntarctic PeninsulaEnvisat ASARSAR imagerysnowmeltWet Snow Zone |
| spellingShingle | CLAUDIO W. MENDES JR JORGE ARIGONY NETO FERNANDO L. HILLEBRAND MARCOS W.D. DE FREITAS JULIANA COSTI JEFFERSON C. SIMÕES Snowmelt retrieval algorithm for the Antarctic Peninsula using SAR imageries Anais da Academia Brasileira de Ciências Antarctic Peninsula Envisat ASAR SAR imagery snowmelt Wet Snow Zone |
| title | Snowmelt retrieval algorithm for the Antarctic Peninsula using SAR imageries |
| title_full | Snowmelt retrieval algorithm for the Antarctic Peninsula using SAR imageries |
| title_fullStr | Snowmelt retrieval algorithm for the Antarctic Peninsula using SAR imageries |
| title_full_unstemmed | Snowmelt retrieval algorithm for the Antarctic Peninsula using SAR imageries |
| title_short | Snowmelt retrieval algorithm for the Antarctic Peninsula using SAR imageries |
| title_sort | snowmelt retrieval algorithm for the antarctic peninsula using sar imageries |
| topic | Antarctic Peninsula Envisat ASAR SAR imagery snowmelt Wet Snow Zone |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652022000201103&tlng=en |
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