Reflectance variation in boreal landscape during the snow melting period using airborne imaging spectroscopy
We aim a better understanding of the effect of spring-time snow melt on the remotely sensed scene reflectance by using an extensive amount of optical spectral data obtained from an airborne hyperspectral campaign in Northern Finland. We investigate the behaviour of thin snow reflectance for differen...
Published in: | International Journal of Applied Earth Observation and Geoinformation |
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2019
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Online Access: | http://hdl.handle.net/10138/298713 |
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ftunivhelsihelda:oai:helda.helsinki.fi:10138/298713 2024-01-07T09:45:29+01:00 Reflectance variation in boreal landscape during the snow melting period using airborne imaging spectroscopy Heinilä, Anna Maaria Kirsikka Salminen, Miia Metsämäki, Sari Pellikka, Petri Kauko Emil Koponen, Sampsa Pulliainen, Jouni Helsinki Institute of Sustainability Science (HELSUS) Department of Geosciences and Geography Earth Change Observation Laboratory (ECHOLAB) 2019-02-06T08:01:01Z 11 application/pdf http://hdl.handle.net/10138/298713 eng eng Elsevier Scientific Publ. Co 10.1016/j.jag.2018.10.017 Heinilä , A M K , Salminen , M , Metsämäki , S , Pellikka , P K E , Koponen , S & Pulliainen , J 2019 , ' Reflectance variation in boreal landscape during the snow melting period using airborne imaging spectroscopy ' , International Journal of Applied Earth Observation and Geoinformation , vol. 76 , pp. 66-76 . https://doi.org/10.1016/j.jag.2018.10.017 bdb64f54-d307-4b48-8e4a-08f096fdc3cb http://hdl.handle.net/10138/298713 000457660800006 cc_by openAccess info:eu-repo/semantics/openAccess 1171 Geosciences 114 Physical sciences Reflectance AISA Spectroscopy Scene reflectance Snow melt NDSI NDVI Boreal forest Land cover classification Fell Snow mapping FSC SCE MODIS GRAIN-SIZE FOREST CANOPY COVERED AREA SPECTRAL ALBEDO SPECTROMETER VEGETATION ACCURACY PRODUCTS FRACTION Article publishedVersion 2019 ftunivhelsihelda 2023-12-14T00:10:49Z We aim a better understanding of the effect of spring-time snow melt on the remotely sensed scene reflectance by using an extensive amount of optical spectral data obtained from an airborne hyperspectral campaign in Northern Finland. We investigate the behaviour of thin snow reflectance for different land cover types, such as open areas, boreal forests and treeless fells. Our results not only confirm the generally known fact that the reflectance of a melting thin snow layer is considerably lower than that of a thick snow layer, but we also present analyses of the reflectance variation over different land covers and in boreal forests as a function of canopy coverage. According to common knowledge, the highly variating reflectance spectra of partially transparent, most likely also contaminated thin snow pack weakens the performance of snow detection algorithms, in particular in the mapping of Fractional Snow Cover (FSC) during the end of the melting period. The obtained results directly support further development of the SCAmod algorithm for FSC retrieval, and can be likewise applied to develop other algorithms for optical satellite data (e.g. spectral unmixing methods), and to perform accuracy assessments for snow detection algorithms. A useful part of this work is the investigation of the competence of Normalized Difference Snow Index (NDSI) in snow detection in late spring, since it is widely used in snow mapping. We conclude, based on the spectral data analysis, that the NDSI-based snow mapping is more accurate in open areas than in forests. However, at the very end of the snow melting period the behavior of the NDSI becomes more unstable and unpredictable in non-forests with shallow snow, increasing the inaccuracy also in non-forested areas. For instance in peatbogs covered by melting snow layer (snow depth <30 cm) the mean NDSI-0.6 was observed, having coefficient of variation as high as 70%, whereas for deeper snow packs the mean NDSI shows positive values. Peer reviewed Article in Journal/Newspaper Northern Finland HELDA – University of Helsinki Open Repository International Journal of Applied Earth Observation and Geoinformation 76 66 76 |
institution |
Open Polar |
collection |
HELDA – University of Helsinki Open Repository |
op_collection_id |
ftunivhelsihelda |
language |
English |
topic |
1171 Geosciences 114 Physical sciences Reflectance AISA Spectroscopy Scene reflectance Snow melt NDSI NDVI Boreal forest Land cover classification Fell Snow mapping FSC SCE MODIS GRAIN-SIZE FOREST CANOPY COVERED AREA SPECTRAL ALBEDO SPECTROMETER VEGETATION ACCURACY PRODUCTS FRACTION |
spellingShingle |
1171 Geosciences 114 Physical sciences Reflectance AISA Spectroscopy Scene reflectance Snow melt NDSI NDVI Boreal forest Land cover classification Fell Snow mapping FSC SCE MODIS GRAIN-SIZE FOREST CANOPY COVERED AREA SPECTRAL ALBEDO SPECTROMETER VEGETATION ACCURACY PRODUCTS FRACTION Heinilä, Anna Maaria Kirsikka Salminen, Miia Metsämäki, Sari Pellikka, Petri Kauko Emil Koponen, Sampsa Pulliainen, Jouni Reflectance variation in boreal landscape during the snow melting period using airborne imaging spectroscopy |
topic_facet |
1171 Geosciences 114 Physical sciences Reflectance AISA Spectroscopy Scene reflectance Snow melt NDSI NDVI Boreal forest Land cover classification Fell Snow mapping FSC SCE MODIS GRAIN-SIZE FOREST CANOPY COVERED AREA SPECTRAL ALBEDO SPECTROMETER VEGETATION ACCURACY PRODUCTS FRACTION |
description |
We aim a better understanding of the effect of spring-time snow melt on the remotely sensed scene reflectance by using an extensive amount of optical spectral data obtained from an airborne hyperspectral campaign in Northern Finland. We investigate the behaviour of thin snow reflectance for different land cover types, such as open areas, boreal forests and treeless fells. Our results not only confirm the generally known fact that the reflectance of a melting thin snow layer is considerably lower than that of a thick snow layer, but we also present analyses of the reflectance variation over different land covers and in boreal forests as a function of canopy coverage. According to common knowledge, the highly variating reflectance spectra of partially transparent, most likely also contaminated thin snow pack weakens the performance of snow detection algorithms, in particular in the mapping of Fractional Snow Cover (FSC) during the end of the melting period. The obtained results directly support further development of the SCAmod algorithm for FSC retrieval, and can be likewise applied to develop other algorithms for optical satellite data (e.g. spectral unmixing methods), and to perform accuracy assessments for snow detection algorithms. A useful part of this work is the investigation of the competence of Normalized Difference Snow Index (NDSI) in snow detection in late spring, since it is widely used in snow mapping. We conclude, based on the spectral data analysis, that the NDSI-based snow mapping is more accurate in open areas than in forests. However, at the very end of the snow melting period the behavior of the NDSI becomes more unstable and unpredictable in non-forests with shallow snow, increasing the inaccuracy also in non-forested areas. For instance in peatbogs covered by melting snow layer (snow depth <30 cm) the mean NDSI-0.6 was observed, having coefficient of variation as high as 70%, whereas for deeper snow packs the mean NDSI shows positive values. Peer reviewed |
author2 |
Helsinki Institute of Sustainability Science (HELSUS) Department of Geosciences and Geography Earth Change Observation Laboratory (ECHOLAB) |
format |
Article in Journal/Newspaper |
author |
Heinilä, Anna Maaria Kirsikka Salminen, Miia Metsämäki, Sari Pellikka, Petri Kauko Emil Koponen, Sampsa Pulliainen, Jouni |
author_facet |
Heinilä, Anna Maaria Kirsikka Salminen, Miia Metsämäki, Sari Pellikka, Petri Kauko Emil Koponen, Sampsa Pulliainen, Jouni |
author_sort |
Heinilä, Anna Maaria Kirsikka |
title |
Reflectance variation in boreal landscape during the snow melting period using airborne imaging spectroscopy |
title_short |
Reflectance variation in boreal landscape during the snow melting period using airborne imaging spectroscopy |
title_full |
Reflectance variation in boreal landscape during the snow melting period using airborne imaging spectroscopy |
title_fullStr |
Reflectance variation in boreal landscape during the snow melting period using airborne imaging spectroscopy |
title_full_unstemmed |
Reflectance variation in boreal landscape during the snow melting period using airborne imaging spectroscopy |
title_sort |
reflectance variation in boreal landscape during the snow melting period using airborne imaging spectroscopy |
publisher |
Elsevier Scientific Publ. Co |
publishDate |
2019 |
url |
http://hdl.handle.net/10138/298713 |
genre |
Northern Finland |
genre_facet |
Northern Finland |
op_relation |
10.1016/j.jag.2018.10.017 Heinilä , A M K , Salminen , M , Metsämäki , S , Pellikka , P K E , Koponen , S & Pulliainen , J 2019 , ' Reflectance variation in boreal landscape during the snow melting period using airborne imaging spectroscopy ' , International Journal of Applied Earth Observation and Geoinformation , vol. 76 , pp. 66-76 . https://doi.org/10.1016/j.jag.2018.10.017 bdb64f54-d307-4b48-8e4a-08f096fdc3cb http://hdl.handle.net/10138/298713 000457660800006 |
op_rights |
cc_by openAccess info:eu-repo/semantics/openAccess |
container_title |
International Journal of Applied Earth Observation and Geoinformation |
container_volume |
76 |
container_start_page |
66 |
op_container_end_page |
76 |
_version_ |
1787427039931793408 |