New Approaches for Removing the Effect of Water Damping on SMAP Freeze/Thaw Mapping
The Northern Quebec landscape is typically covered by numerous lakes. The lowest emissivity of water bodies dominates the brightness temperature (Tb) data measured over this region. Thus, it is necessary to eliminate the effect of water bodies from Tb measurements. The primary objective of this stud...
Published in: | Canadian Journal of Remote Sensing |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English French |
Published: |
Taylor & Francis Group
2019
|
Subjects: | |
Online Access: | https://doi.org/10.1080/07038992.2019.1638236 https://doaj.org/article/3ad76478261f4fd5867b70a904b0c046 |
id |
ftdoajarticles:oai:doaj.org/article:3ad76478261f4fd5867b70a904b0c046 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:3ad76478261f4fd5867b70a904b0c046 2024-09-15T18:40:02+00:00 New Approaches for Removing the Effect of Water Damping on SMAP Freeze/Thaw Mapping Cheima Touati Tahiana Ratsimbazafy Ralf Ludwig Monique Bernier 2019-07-01T00:00:00Z https://doi.org/10.1080/07038992.2019.1638236 https://doaj.org/article/3ad76478261f4fd5867b70a904b0c046 EN FR eng fre Taylor & Francis Group http://dx.doi.org/10.1080/07038992.2019.1638236 https://doaj.org/toc/1712-7971 1712-7971 doi:10.1080/07038992.2019.1638236 https://doaj.org/article/3ad76478261f4fd5867b70a904b0c046 Canadian Journal of Remote Sensing, Vol 45, Iss 3-4, Pp 405-422 (2019) Environmental sciences GE1-350 Technology T article 2019 ftdoajarticles https://doi.org/10.1080/07038992.2019.1638236 2024-08-05T17:49:16Z The Northern Quebec landscape is typically covered by numerous lakes. The lowest emissivity of water bodies dominates the brightness temperature (Tb) data measured over this region. Thus, it is necessary to eliminate the effect of water bodies from Tb measurements. The primary objective of this study is to develop two approaches to correct the Soil Moisture Active Passive brightness temperature (SMAP L1C), collected between January and December of 2016, for the damping effect of water bodies within each 36 km by 36 km pixel. The first algorithm normalizes Tb with the intercept of its linear regression versus the water fraction of each pixel. A second algorithm used Tb regression with water fraction by vegetation classes for each scene. Surface soil temperature and moisture measured near Umiujaq were used to validate Tb correction. The proposed Tb corrections resolve the divergence observed with SMAP standard correction when the water fraction is higher than 20%. Corrected brightness temperature is then tested for mapping the soil freeze/thaw state using the Normalized Polarization Ratio. Agreements of up to 90% (ascending orbit) and 79% (descending orbit) were reached for the proposed approach versus 64% and 50% for the existing approach. Article in Journal/Newspaper Umiujaq Directory of Open Access Journals: DOAJ Articles Canadian Journal of Remote Sensing 45 3-4 405 422 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English French |
topic |
Environmental sciences GE1-350 Technology T |
spellingShingle |
Environmental sciences GE1-350 Technology T Cheima Touati Tahiana Ratsimbazafy Ralf Ludwig Monique Bernier New Approaches for Removing the Effect of Water Damping on SMAP Freeze/Thaw Mapping |
topic_facet |
Environmental sciences GE1-350 Technology T |
description |
The Northern Quebec landscape is typically covered by numerous lakes. The lowest emissivity of water bodies dominates the brightness temperature (Tb) data measured over this region. Thus, it is necessary to eliminate the effect of water bodies from Tb measurements. The primary objective of this study is to develop two approaches to correct the Soil Moisture Active Passive brightness temperature (SMAP L1C), collected between January and December of 2016, for the damping effect of water bodies within each 36 km by 36 km pixel. The first algorithm normalizes Tb with the intercept of its linear regression versus the water fraction of each pixel. A second algorithm used Tb regression with water fraction by vegetation classes for each scene. Surface soil temperature and moisture measured near Umiujaq were used to validate Tb correction. The proposed Tb corrections resolve the divergence observed with SMAP standard correction when the water fraction is higher than 20%. Corrected brightness temperature is then tested for mapping the soil freeze/thaw state using the Normalized Polarization Ratio. Agreements of up to 90% (ascending orbit) and 79% (descending orbit) were reached for the proposed approach versus 64% and 50% for the existing approach. |
format |
Article in Journal/Newspaper |
author |
Cheima Touati Tahiana Ratsimbazafy Ralf Ludwig Monique Bernier |
author_facet |
Cheima Touati Tahiana Ratsimbazafy Ralf Ludwig Monique Bernier |
author_sort |
Cheima Touati |
title |
New Approaches for Removing the Effect of Water Damping on SMAP Freeze/Thaw Mapping |
title_short |
New Approaches for Removing the Effect of Water Damping on SMAP Freeze/Thaw Mapping |
title_full |
New Approaches for Removing the Effect of Water Damping on SMAP Freeze/Thaw Mapping |
title_fullStr |
New Approaches for Removing the Effect of Water Damping on SMAP Freeze/Thaw Mapping |
title_full_unstemmed |
New Approaches for Removing the Effect of Water Damping on SMAP Freeze/Thaw Mapping |
title_sort |
new approaches for removing the effect of water damping on smap freeze/thaw mapping |
publisher |
Taylor & Francis Group |
publishDate |
2019 |
url |
https://doi.org/10.1080/07038992.2019.1638236 https://doaj.org/article/3ad76478261f4fd5867b70a904b0c046 |
genre |
Umiujaq |
genre_facet |
Umiujaq |
op_source |
Canadian Journal of Remote Sensing, Vol 45, Iss 3-4, Pp 405-422 (2019) |
op_relation |
http://dx.doi.org/10.1080/07038992.2019.1638236 https://doaj.org/toc/1712-7971 1712-7971 doi:10.1080/07038992.2019.1638236 https://doaj.org/article/3ad76478261f4fd5867b70a904b0c046 |
op_doi |
https://doi.org/10.1080/07038992.2019.1638236 |
container_title |
Canadian Journal of Remote Sensing |
container_volume |
45 |
container_issue |
3-4 |
container_start_page |
405 |
op_container_end_page |
422 |
_version_ |
1810484359439843328 |