Searched for: +
(1 - 20 of 64)

Pages

document
El Hajj, Marcel M. (author), Steele-Dunne, S.C. (author), Almashharawi, Samer K. (author), Tian, X. (author), Johansen, Kasper (author), Camargo, Omar A.Lopez (author), Amezaga-Sarries, Adria (author), Mas-Vinolas, Andreu (author), McCabe, Matthew F. (author)
Soil moisture (SM) is an important state variable in land surface models. Here, we investigate the potential of a ground-based global navigation satellite system receiver with two linearly polarized antennas that measure the interference power (IP) of direct and reflected signals in horizontal polarization (H-pol) and vertical polarization (V...
journal article 2024
document
Shan, X. (author), Steele-Dunne, S.C. (author), Hahn, Sebastian (author), Wagner, Wolfgang (author), Bonan, Bertrand (author), Albergel, Clement (author), Calvet, Jean Christophe (author), Ku, Ou (author)
ASCAT normalized backscatter (σ<sub>40</sub><sup>o</sup>) and slope (σ<sup>′</sup>) contain valuable information about soil moisture and vegetation. While σ<sub>40</sub><sup>o</sup> has been assimilated to constrain soil moisture, sometimes together with Leaf Area Index (LAI), this study is the first to assimilate σ<sup>′</sup> directly to...
journal article 2024
document
den Besten, N.I. (author), Steele-Dunne, S.C. (author), Mahmud, Ashfak (author), Jackson, Daniel (author), Aouizerats, Benjamin (author), de Jeu, Richard (author), Burger, Rogier (author), Houborg, Rasmus (author), McGlinchey, Mark (author), van der Zaag, P. (author)
Sentinel-1 observes the whole globe every 12 days (6 days when both satellites were operational) and provides a wealth of data relevant to agriculture. Sugarcane cultivators could potentially benefit from these data by using them to assist operational and management practices. However, first, thorough understanding is needed of Sentinel-1...
journal article 2023
document
Huber, Manuel (author), Kumar, V. (author), Steele-Dunne, S.C. (author), Rommen, Bjorn (author)
Reliable crop monitoring is paramount to achieve the objectives of the Common Agricultural Policy (CAP) and Food and Agriculture Organization. Synthetic Aperture Radar (SAR) provides high-resolution imaging and all-weather data acquisition capabilities for crop monitoring. This study investigates the sensitivity of parcel-level Sentinel-1...
conference paper 2023
document
Nikaein, T. (author), López-Dekker, Paco (author), Steele-Dunne, S.C. (author), Kumar, V. (author), Huber, M. (author)
In this article, our aim is to estimate synthetic aperture radar (SAR) observables, such as backscatter in VV and VH polarizations, as well as the VH/VV ratio, cross ratio, and interferometric coherence in VV, from agricultural fields. In this study, we use the decision support system for agrotechnology transfer (DSSAT) crop-growth simulation...
journal article 2023
document
Shorachi, Maurice (author), Kumar, V. (author), Steele-Dunne, S.C. (author)
Drought is a major natural hazard that impacts agriculture, the environment, and socio-economic conditions. In 2018 and 2019, Europe experienced a severe drought due to below average precipitation and high temperatures. Drought stress affects the moisture content and structure of agricultural crops and can result in lower yields. Synthetic...
journal article 2022
document
Khabbazan, S. (author), Steele-Dunne, S.C. (author), Vermunt, P.C. (author), Judge, J. (author), Vreugdenhil, M. (author), Gao, G. (author)
The presence of surface water on the canopy affects radar backscatter. However, its influence on the relationship between radar backscatter and crop biophysical parameters has not been investigated. The aim of this study was to quantify the influence of surface canopy water (SCW) on the relationship between L-band radar backscatter and...
journal article 2022
document
Vermunt, P.C. (author), Steele-Dunne, S.C. (author), Khabbazan, S. (author), Judge, Jasmeet (author), van de Giesen, N.C. (author)
Microwave observations are sensitive to vegetation water content (VWC). Consequently, the increasing temporal and spatial resolution of spaceborne microwave observations creates a unique opportunity to study vegetation water dynamics and its role in the diurnal water cycle. However, we currently have a limited understanding of sub-daily...
journal article 2022
document
Vermunt, P.C. (author), Steele-Dunne, S.C. (author), Khabbazan, S. (author), Kumar, V. (author), Judge, Jasmeet (author)
For a good interpretation of radar backscatter sensitivity to vegetation water dynamics, we need to know which parts of the vegetation layer control that backscatter. However, backscatter sensitivity to different depths in the canopy is poorly understood. This is partly caused by a lack of observational data to describe the vertical moisture...
journal article 2022
document
Vreugdenhil, Mariette (author), Greimeister-Pfeil, Isabella (author), Preimesberger, Wolfgang (author), Camici, Stefania (author), Dorigo, Wouter (author), Enenkel, Markus (author), van der Schalie, Robin (author), Steele-Dunne, S.C. (author), Wagner, Wolfgang (author)
Agricultural droughts are extreme events which are often a result of interplays between multiple hydro-meteorological processes. Therefore, assessing drought occurrence, extent, duration and intensity is complex and requires the combined use of multiple variables, such as temperature, rainfall, soil moisture (SM) and vegetation state. The...
review 2022
document
De Lannoy, Gabriëlle J.M. (author), Bechtold, Michel (author), Albergel, Clément (author), Brocca, Luca (author), Calvet, Jean Christophe (author), Carrassi, Alberto (author), Crow, Wade T. (author), de Rosnay, Patricia (author), Steele-Dunne, S.C. (author)
The beginning of the 21<sup>st</sup> century is marked by a rapid growth of land surface satellite data and model sophistication. This offers new opportunities to estimate multiple components of the water cycle via satellite-based land data assimilation (DA) across multiple scales. By resolving more processes in land surface models and by...
review 2022
document
Kumar, Sujay (author), Kolassa, Jana (author), Reichle, Rolf (author), Crow, Wade (author), de Lannoy, Gabrielle (author), de Rosnay, Patricia (author), MacBean, Natasha (author), Quaife, Tristan (author), Steele-Dunne, S.C. (author)
The task of quantifying spatial and temporal variations in terrestrial water, energy, and vegetation conditions is challenging due to the significant complexity and heterogeneity of these conditions, all of which are impacted by climate change and anthropogenic activities. To address this challenge, Earth Observations (EOs) of the land and...
review 2022
document
Kumar, V. (author), Huber, Manuel (author), Rommen, Björn (author), Steele-Dunne, S.C. (author)
Synthetic Aperture Radar (SAR) data handling, processing, and interpretation are barriers preventing a rapid uptake of SAR data by application specialists and non-expert domain users in the field of agricultural monitoring. To improve the accessibility of Sentinel-1 data, we have generated a reduced-volume, multi-year Sentinel-1 SAR database....
journal article 2022
document
Petchiappan, A. (author), Steele-Dunne, S.C. (author), Vreugdenhil, M. (author), Hahn, S. (author), Wagner, W. (author), Oliveira, R. (author)
Microwave observations are sensitive to plant water content and could therefore provide essential information on biomass and plant water status in ecological and agricultural applications. The combined data record of the C-band scatterometers on the European Remote-Sensing Satellites (ERS)-1/2, the Metop (Meteorological Operational satellite)...
journal article 2022
document
Mueller, Marlin M. (author), Dubois, Clémence (author), Jagdhuber, Thomas (author), Hellwig, Florian M. (author), Pathe, Carsten (author), Schmullius, Christiane (author), Steele-Dunne, S.C. (author)
Forests’ ecosystems are an essential part of the global carbon cycle with vast carbon storage potential. These systems are currently under external pressures showing increasing change due to climate change. A better understanding of the biophysical properties of forests is, therefore, of paramount importance for research and monitoring...
journal article 2022
document
Nikaein, T. (author), Kummer, Vineet (author), Steele-Dunne, S.C. (author), López-Dekker, Paco (author)
This paper presents an approach to implement a forward model for Sentinel-1 copol and crosspol backscatter and coherence using crop bio-geophysical parameters namely leaf area index, biomass, canopy height, soil moisture and root zone moisture as inputs for the maize. These required input parameters are generated using Decision Support System...
conference paper 2022
document
Shan, X. (author), Steele-Dunne, S.C. (author), Huber, M. (author), Hahn, Sebastian (author), Wagner, Wolfgang (author), Bonan, Bertrand (author), Albergel, Clement (author), Calvet, Jean-Christophe (author), Ku, Ou (author), Georgievska, Sonja (author)
A Deep Neural Network (DNN) is used to estimate the Advanced Scatterometer (ASCAT) C-band microwave normalized backscatter (σ40o), slope (σ′) and curvature (σ″) over France. The Interactions between Soil, Biosphere and Atmosphere (ISBA) land surface model (LSM) is used to produce land surface variables (LSVs) that are input to the DNN. The DNN...
journal article 2022
document
Jamalinia, E. (author), Sadeghi Tehrani, F. (author), Steele-Dunne, S.C. (author), Vardon, P.J. (author)
Climatic conditions and vegetation cover influence water flux in a dike, and potentially the dike stability. A comprehensive numerical simulation is computationally too expensive to be used for the near real-time analysis of a dike network. Therefore, this study investigates a random forest (RF) regressor to build a data-driven surrogate for a...
journal article 2021
document
Konings, Alexandra G. (author), Saatchi, Sassan S. (author), Frankenberg, Christian (author), Keller, Michael (author), Leshyk, Victor (author), Anderegg, William R.L. (author), Humphrey, Vincent (author), Steele-Dunne, S.C. (author), Wang, Yujie (author)
Droughts in a warming climate have become more common and more extreme, making understanding forest responses to water stress increasingly pressing. Analysis of water stress in trees has long focused on water potential in xylem and leaves, which influences stomatal closure and water flow through the soil-plant-atmosphere continuum. At the...
review 2021
document
den Besten, N.I. (author), Steele-Dunne, S.C. (author), de Jeu, Richard (author), van der Zaag, P. (author)
Waterlogging is an increasingly important issue in irrigated agriculture that has a detri-mental impact on crop productivity. The above-ground effect of waterlogging on crops is hard to distinguish from water deficit stress with remote sensing, as responses such as stomatal closure and leaf wilting occur in both situations. Currently,...
journal article 2021
Searched for: +
(1 - 20 of 64)

Pages