Barrée M., Mialon A., Pellarin T., Parrens M., Biron Romain, Lemaitre F., Gascoin S., Kerr Y. H. (2021). Soil moisture and vegetation optical depth retrievals over heterogeneous scenes using LEWIS L-band radiometer. International Journal of Applied Earth Observation and Geoinformation, 102, p. 102424 [9 p.]. ISSN 1569-8432.
Titre du document
Soil moisture and vegetation optical depth retrievals over heterogeneous scenes using LEWIS L-band radiometer
Barrée M., Mialon A., Pellarin T., Parrens M., Biron Romain, Lemaitre F., Gascoin S., Kerr Y. H.
Source
International Journal of Applied Earth Observation and Geoinformation, 2021,
102, p. 102424 [9 p.] ISSN 1569-8432
The Soil Moisture and Ocean Salinity (SMOS) satellite has been providing global data for more than 11 years. The algorithm to retrieve surface soil moisture (SM) and vegetation optical depth (VOD) from Brightness Temperatures (TB) has constantly evolved as our understanding of the instrument and of the responses to various ecosystems increased. The evolution of the radiative transfer modelling used in the inversion process is in part based upon ground measurements done on experimental sites. We present the particular case of an L-band radiometer placed on top of a 800- meter-high cliff. This design allows us to study large and various scenes when compared to classical experiments where a radiometer is placed 10-20 m above a surface. With our set up, the footprints cover areas larger than 300 m in diameter, covering thus several land use types and the footprint can be directed towards different dominant land classes (forest, crops, urban etc...). This paper presents the whole set up consisting of in situ measurements (soil moisture and surface temperatures) and L-band radiometry acquired by the LEWIS instrument at high incidence angles. We perform SM/VOD retrievals from brightness temperatures using various configurations which are compared to the in situ observations. We test in particular a 2-VOD retrieval approach that consists in deriving one SM for the entire scene but two VOD, one for agricultural/low vegetation and a VOD for the forest parts, which improves the performance of the SM/VOD retrievals.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
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Bioclimatologie [072]
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Etudes, transformation, conservation du milieu naturel [082]
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Télédétection [126]
