Landscape freeze/thaw mapping from active and passive microwave Earth observations over the Tursujuq National Park, Quebec, Canada

Author:
Touati C., Ratsimbazafy T., Poulin J., Bernier M., Homayouni S. & Ludwig R.
Year:
2021
Journal:
Écoscience
Pages:
28(3): 421–433
Url:
https://doi.org/10.1080/11956860.2021.1969790
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We investigated the sensitivity to vegetation cover type of active (PALSAR) and passive (SMAP) freeze/thaw (F/T) classification. We also used F/T classification from high-resolution PALSAR data (30 m) to follow the evolution of frozen and thawed soil states obtained from an adaptive algorithm with low-resolution SMAP data (36 km). We used PALSAR and SMAP scenes acquired from June 2015 to January 2017 over the Tursujuq National Park (Umiujaq, Quebec, Canada). A new F/T algorithm with a specific reference threshold under each vegetation type (shrub, grass, lichen, wetland, and bare land) is proposed to classify PALSAR pixels. The validation of the PALSAR F/T classification with soil temperature at ~5 cm depth revealed a greater overall accuracy (> 80%), with horizontal transmitted and vertical received (HV) thresholds. The PALSAR F/T classification shows that a SMAP pixel is classified as frozen when more than 50% of its area is frozen at the surface. We confirmed the sensitivity to vegetation cover type of passive and active F/T classification with L-band sensor. Keywords: PALSAR; SMAP; vegetation; freeze/thaw algorithms; Nunavik.
Id:
34021
Submitter:
zdenek
Post_time:
Sunday, 02 January 2022 15:47