Conference Agenda
Overview and details of the sessions of this conference. Please select a date or location to show only sessions at that day or location. Please select a single session for detailed view (with abstracts and downloads if available).
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Daily Overview |
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📌Poster Session and Networking Aperitivo 🍷 Location: Lower Lobby | |
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Developing a UAV-SAR Measurement Concept for Diurnal Vegetation Water Monitoring 1: TUD Dresden University of Technology, Professorship in Environmental Remote Sensing, Dresden, Germany; 2: Czech University of Life Sciences, Prague, Czech Republic; 3: TUD Dresden University of Technology, Chair of Forest Sites and Hydrology, Dresden, Germany Monitoring vegetation water dynamics at sub-daily scales can reveal early hydraulic stress in forests and improve drought early-warning systems. Existing radar satellites such as Sentinel-1 provide frequent, all-weather observations of vegetation structure and moisture but lack the temporal resolution to resolve diurnal fluctuations that reflect plant water transport processes. Upcoming missions like ESA’s BIOMASS and ROSE-L will advance forest parameter retrievals, yet complementary UAV-scale measurements are needed to capture short-term canopy moisture changes and support calibration and validation. This contribution outlines a measurement concept for a UAV-based multi-band SAR system (C/L/P) to monitor diurnal changes in vegetation water dynamics at the forest-stand scale. The approach builds on recent studies linking radar backscatter to canopy hydraulic properties (1–4) and overnight rehydration patterns, which signal early drought stress (5). As a precursor, we analyse Sentinel-1 backscatter in combination with Sentinel-2 vegetation indices to characterize radar–optical relationships and moisture regime variability across selected German forest sites (six beech-dominated, three pine-dominated, and five pre-forest stands). This analysis will guide site selection for UAV-SAR campaigns by identifying locations with contrasting canopy phenologies and moisture responses. Subsequent UAV campaigns will acquire multi-band SAR observations three times daily, accompanied by in-situ measurements of soil moisture, sap flow, and stem radius variations. Integrating these data streams will allow us to model root–canopy water exchange and validate radar-derived vegetation water metrics at unprecedented temporal resolution. By bridging the temporal gap between satellite and ground observations, this work contributes to algorithm development for vegetation moisture retrieval and supports the integration of UAV-SAR in calibration and validation frameworks for future ESA missions. 1. Chaparro D, Piles M, Vall-llossera M, Camps A, Konings AG, Entekhabi D. L-band vegetation optical depth seasonal metrics for crop yield assessment. Remote Sensing of Environment. 2018;212:249-259. doi:10.1016/j.rse.2018.04.049 2. Konings AG, Yu Y, Xu L, Yang Y, Schimel DS, Saatchi SS. Active microwave observations of diurnal and seasonal variations of canopy water content across the humid African tropical forests. Geophysical Research Letters. 2017;44(5):2290-2299. doi:10.1002/2016GL072388 3. Steele-Dunne S, Friesen J, van de Giesen N. Using Diurnal Variation in Backscatter to Detect Vegetation Water Stress. IEEE Transactions on Geoscience and Remote Sensing. 2012;50(7):2618-2629. doi:10.1109/TGRS.2012.2194156 4. Steele-Dunne S, Basto A, de Zan F, et al. SLAINTE: A SAR mission concept for sub-daily microwave remote sensing of vegetation. In: EUSAR 2024; 15th European Conference on Synthetic Aperture Radar. 2024:870-872. Accessed June 25, 2025. https://ieeexplore.ieee.org/abstract/document/10659518 5. Ziegler Y, Grote R, Alongi F, Knüver T, Ruehr NK. Capturing drought stress signals: the potential of dendrometers for monitoring tree water status. Tree Physiol. 2024;44(12). doi:10.1093/treephys/tpae140 | |
