Publication Details |
| Category | Text Publication |
| Reference Category | Journals |
| DOI | 10.1109/JSTARS.2026.3673725 |
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| Title (Primary) | A novel active-microwave method to estimate 1 km vegetation optical depth over the Heihe River Basin |
| Author | Lu, Z.; Fan, L.; De Lannoy, G.; Bai, X.; Liu, X.; Xing, Z.; Zhou, Z.; Zeng, J.; Frappart, F.; Peng, J.
; Che, T.; Geng, L.; Li, X.; Li, X.; Baghdadi, N. N.; Wigneron, J.-P. |
| Source Titel | IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing |
| Year | 2026 |
| Department | RS |
| Volume | 19 |
| Page From | 11560 |
| Page To | 11580 |
| Language | englisch |
| Topic | T5 Future Landscapes |
| Supplements | Supplement 1 |
| Keywords | Vegetation mapping; Backscatter; Soil moisture; Sentinel-1; Spatial resolution; Rivers; Remote sensing; Mathematical models; Synthetic aperture radar; Grasslands |
| Abstract | The present study proposes a method for retrieving C-band vegetation optical depth (VOD) using high-resolution Sentinel-1 VV-polarized backscatter data over the Heihe River Basin. The water cloud model (WCM) is coupled separately with two semi-empirical soil backscatter models—the Dubois model and the Oh model—as well as with the linear empirical Ulaby model. Pixel-wise soil model parameters are derived using a random forest approach based on land surface parameters, while vegetation model parameters are calibrated on a daily basis. This combined strategy effectively enhances the accuracy of VOD retrieval. The performance of the three VOD products was evaluated through correlation analysis with biomass and vegetation indices, followed by a comparative analysis among the different VOD retrievals. The results indicate that the VOD derived from the WCM coupled with the Dubois model outperforms the alternative approaches. This is evidenced by its higher correlations with vegetation indices, yielding average correlation coefficients (R) of 0.80 with the normalized difference vegetation index, 0.80 with the leaf area index, and 0.80 with the enhanced vegetation index. Furthermore, a higher degree of agreement was found between the soil backscatter and the simulations using the Dubois model, with a coefficient of determination (R2) of 0.82, a root mean square error of 1.83 dB, a bias of 0.18 dB and a mean absolute error of 1.2 dB. The findings of this study demonstrate that the proposed VOD algorithms, utilizing the WCM in conjunction with the Dubois model, offers the prospect of active high-resolution VODs. |
| Lu, Z., Fan, L., De Lannoy, G., Bai, X., Liu, X., Xing, Z., Zhou, Z., Zeng, J., Frappart, F., Peng, J., Che, T., Geng, L., Li, X., Li, X., Baghdadi, N. N., Wigneron, J.-P. (2026): A novel active-microwave method to estimate 1 km vegetation optical depth over the Heihe River Basin IEEE J. Sel. Top. Appl. Earth Observ. Remote Sens. 19 , 11560 - 11580 10.1109/JSTARS.2026.3673725 |
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