Publications in Scientific Journals:
W. Crow, W. Wagner, V. Naeimi:
"The impact of radar incidence angle on soil moisture retrieval skill";
IEEE Geoscience And Remote Sensing Letters,
The impact of measurement incidence angle (θ) on
the accuracy of radar-based surface soil-moisture (Θs) retrievals
is largely unknown due to discrepancies in theoretical backscatter
models as well as limitations in the availability of sufficiently
extensive ground-based Θs observations for validation. Here, we
apply a data-assimilation-based evaluation technique for remotely
sensed Θs retrievals that does not require ground-based soilmoisture
observations to examine the sensitivity of skill in surface
Θs retrievals to variations in θ. Past results with the evaluation
approach have shown that it is capable of detecting relative variations
in the anomaly correlation coefficient between remotely
sensed Θs retrievals and ground-truth soil-moisture measurements.
Application of the evaluation approach to the Vienna University
of Technology (TUWien) European Remote Sensing (ERS)
scatterometer Θs data set over regional-scale (∼10002 km2) domains
in the Southern Great Plains and southeastern (SE) regions
of the U.S. indicate a relative reduction in correlation-based skill of
23% to 30% for Θs retrievals obtained from far-field (θ > 50◦)
ERS observations relative to Θs estimates obtained at θ < 26◦.
Such relatively modest sensitivity to θ is consistent with Θs
retrieval noise predictions made using the TU-Wien ERS Water
Retrieval Package 5 backscatter model. However, over moderate
vegetation cover in the SE domain, the coupling of a bare soil
backscatter model with a "vegetation water cloud" canopy model
is shown to overestimate the impact of θ on Θs retrieval skill.
"Official" electronic version of the publication (accessed through its Digital Object Identifier - DOI)
Electronic version of the publication:
Created from the Publication Database of the Vienna University of Technology.