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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Multifrequency and Full-Polarimetric SAR Assessment for Estimating Above Ground Biomass and Leaf Area Index in the Amazon Varzea Wetlands

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Author(s):
Pereira, Luciana O. [1, 2] ; Furtado, Luiz F. A. [1, 3] ; Novo, Evlyn M. L. M. [1] ; Sant'Anna, Sidnei J. S. [1] ; Liesenberg, Veraldo [4] ; Silva, Thiago S. F. [5]
Total Authors: 6
Affiliation:
[1] Brazilian Natl Inst Space Res INPE, BR-12245 Sao Jose Dos Campos, SP - Brazil
[2] Univ Exeter, Exeter EX4 4QJ, Devon - England
[3] Univ Fed Rio de Janeiro, Dept Geog, BR-21941916 Rio de Janeiro, RJ - Brazil
[4] Santa Catarina State Univ UDESC, Dept Forest Engn, BR-88520000 Lages, SC - Brazil
[5] Sao Paulo State Univ, UNESP, Ecosyst Dynam Observ, Inst Geosci & Exact Sci, BR-13506900 Rio Claro, SP - Brazil
Total Affiliations: 5
Document type: Journal article
Source: REMOTE SENSING; v. 10, n. 9 SEP 2018.
Web of Science Citations: 3
Abstract

The aim of this study is to evaluate the potential of multifrequency and Full-polarimetric Synthetic Aperture Radar (SAR) data for retrieving both Above Ground Biomass (AGB) and Leaf Area Index (LAI) in the Amazon floodplain forest environment. Two specific questions were proposed: (a) Does multifrequency SAR data perform more efficiently than single-frequency data in estimating LAI and AGB of varzea forests?; and (b) Are quad-pol SAR data more efficient than single- and dual-pol SAR data in estimating LAI and AGB of varzea forest? To answer these questions, data from different sources (TerraSAR-X Multi Look Ground Range Detected (MGD), Radarsat-2 Standard Qual-Pol, advanced land observing satellite (ALOS)/ phased-arrayed L-band SAR (PALSAR-1). Fine-beam dual (FDB) and quad Polarimetric mode) were combined in 10 different scenarios to model both LAI and AGB. A R-platform routine was implemented to automatize the selection of the best regression models. Results indicated that ALOS/PALSAR variables provided the best estimates for both LAI and AGB. Single-frequency L-band data was more efficient than multifrequency SAR. PALSAR-FDB HV-dB provided the best LAI estimates during low-water season. The best AGB estimates at high-water season were obtained by PALSAR-1 quad-polarimetric data. The top three features for estimating AGB were proportion of volumetric scattering and both the first and second dominant phase difference between trihedral and dihedral scattering, extracted from Van Zyl and Touzi decomposition, respectively. The models selected for both AGB and LAI were parsimonious. The Root Mean Squared Error (RMSEcv), relative overall RMSEcv (%) and R-2 value for LAI were 0.61%, 0.55% and 13%, respectively, and for AGB, they were 74.6 t.ha(-1), 0.88% and 46%, respectively. These results indicate that L-band (ALOS/PALSAR-1) has a high potential to provide quantitative and spatial information about structural forest attributes in floodplain forest environments. This potential may be extended not only with PALSAR-2 data but also to forthcoming missions (e.g., NISAR, Global Ecosystems Dynamics Investigation Lidar (GEDI), BIOMASS, Tandem-L) for promoting wall-to-wall AGB mapping with a high level of accuracy in dense tropical forest regions worldwide. (AU)

FAPESP's process: 11/23594-8 - Remote sensing applications for modeling human impacts on the ecological properties of wetland and aquatic environments in the Solimões/Amazon floodplain
Grantee:Evlyn Márcia Leão de Moraes Novo
Support Opportunities: Regular Research Grants