Biomass of dense forests related to L-Band SAR backscatter ?
Synthetic aperture radar (SAR) is one of the most promising remote sensor to map forest carbon. The unique spaceborne and long-wavelength SAR data currently available are L-band data, but their relationship with forest biomass is still under controversy, particularly for high biomass values. While many studies assume a complete loss of sensitivity above a saturation point, typically around 100 t.ha-1, others assume a continuous positive correlation between SAR backscatter and biomass. The objective of this paper is to revisit the relationship between L-band SAR backscatter and dense tropical forest biomass for a large range of biomass values, using both theoretical and experimental approaches. Both approaches revealed that after reaching a maximum value, SAR backscatter correlates negatively with forest biomass. This phenomenon is interpreted as a signal attenuation from the forest canopy as the canopy becomes denser. This result has strong implication for L-band vegetation mapping as it can lead to a more-than-expected biomass under-estimation.
| Main Authors: | , , , , , |
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| Format: | conference_item biblioteca |
| Language: | eng |
| Published: |
s.n.
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| Subjects: | U30 - Méthodes de recherche, K01 - Foresterie - Considérations générales, U10 - Informatique, mathématiques et statistiques, |
| Online Access: | http://agritrop.cirad.fr/574575/ http://agritrop.cirad.fr/574575/1/document_574575.pdf |
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| Summary: | Synthetic aperture radar (SAR) is one of the most promising remote sensor to map forest carbon. The unique spaceborne and long-wavelength SAR data currently available are L-band data, but their relationship with forest biomass is still under controversy, particularly for high biomass values. While many studies assume a complete loss of sensitivity above a saturation point, typically around 100 t.ha-1, others assume a continuous positive correlation between SAR backscatter and biomass. The objective of this paper is to revisit the relationship between L-band SAR backscatter and dense tropical forest biomass for a large range of biomass values, using both theoretical and experimental approaches. Both approaches revealed that after reaching a maximum value, SAR backscatter correlates negatively with forest biomass. This phenomenon is interpreted as a signal attenuation from the forest canopy as the canopy becomes denser. This result has strong implication for L-band vegetation mapping as it can lead to a more-than-expected biomass under-estimation. |
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