Talks and Poster Presentations (with Proceedings-Entry):
S. Hahn, W. Wagner, M. Vreugdenhil, T. Melzer, A. Abdulrahman:
"Challenges for Soil Moisture Retrieval from C-band Backscatter";
Talk: EUMETSAT Meteorological Satellite Conference,
- 09-20-2013; in: "Proceedings of the 2013 EUMETSAT Metereological Satellite Conference",
Space-borne scatterometers have proven to be a valuable tool for deriving soil moisture information over land. A strong relationship between the scatterometer backscatter measurements and the different dielectric properties of dry and wet soil made this possible in the first place. However, this assumption does often not hold in arid and semi-arid environments. In order to obtain correct and accurate soil moisture information also in these areas, changes in surface characteristics influencing the backscatter and its dynamics needs to be understood. This study examines the different circumstances affecting backscatter measurements in arid and semi-arid environments, which are important in the context of the semi-empiric change detection method for soil moisture retrieval implemented in WARP (WAter Retrieval Package). It was found that especially sand deserts are prone to be affected by azimuthal anisotropy and Bragg scattering, which is consistent with previous studies. The new aspect, however, is that also seasonal characteristics of anisotropy have been observed. Another remarkable finding of this study was unexpected backscatter increase during dry spells in areas identified as alluvial fans and pediments. A good understanding of backscatter characteristics in arid regions and their underlying physical processes is relevant on the one hand for corrections purposes (e.g. during soil moisture retrieval) and on the other hand for the identification of new possible applications of scatterometer measurements in this environment.
Electronic version of the publication:
Created from the Publication Database of the Vienna University of Technology.