First mapping of polarization-dependent vegetation optical depth and soil moisture from SMAP L-band radiometry - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Remote Sensing of Environment Année : 2024

First mapping of polarization-dependent vegetation optical depth and soil moisture from SMAP L-band radiometry

Résumé

Soil moisture (SM) and vegetation optical depth (VOD) estimates using passive microwave remote sensing at Lband (1.4 GHz) are essential for attaining a better understanding of water exchanges at the land-atmosphere interface. However, current retrieval algorithms often ignore the polarization dependence of vegetation effects. This study proposed a parameter self-calibrating framework for the multi-channel collaborative algorithm (MCCA) and presented a new SM and the first polarization-dependent VOD product based on the dual-polarized L-band observations at a fixed angle (40 degrees) from the NASA Soil Moisture Active Passive (SMAP) mission. The parameter self-calibrating framework utilizes an information theory-based approach to obtain surface roughness and effective scattering albedo globally. Furthermore, the MCCA does not require auxiliary data for vegetation or soil moisture to constrain the retrieval process. Comparison with other SM and VOD products, such as MT-DCA version 5, DCA, SCA-H, SCA-V from SMAP Level-3 products version 8, and SMAP-IB, demonstrate analogous spatial patterns. The MCCA-derived SM exhibits the lowest unbiased root mean square deviation (ubRMSD, about 0.055 m3/m3), followed by SMAP-IB and DCA (0.061 m3/m3), with an overall Pearson's correlation coefficient of 0.744 (SMAP-IB performed best with R = 0.764) when evaluated against in-situ observations from 18 dense soil moisture networks. The MCCA generates VOD values for both vertical and horizontal polarization, demonstrating a slight polarization difference of vegetation effect at the satellite scale. Both VODs exhibit a strong linear relationship with above-ground biomass and canopy height. The polarization difference of VODs is primarily observed in densely vegetated and arid areas.
Fichier non déposé

Dates et versions

hal-04474658 , version 1 (23-02-2024)

Identifiants

Citer

Zhiqing Peng, Tianjie Zhao, Jiancheng Shi, Lu Hu, Nemesio Rodríguez-Fernández, et al.. First mapping of polarization-dependent vegetation optical depth and soil moisture from SMAP L-band radiometry. Remote Sensing of Environment, 2024, 302, pp.113970. ⟨10.1016/j.rse.2023.113970⟩. ⟨hal-04474658⟩
34 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More