Analysis of scatterometer observations of Saharan Ergs using a simple rough facet model
Document Type
Article
Publication Date
2004
Publication Title
2004 IEEE International Geoscience and Remote Sensing Symposium Proceedings
Publisher
Institute of Electrical and Electronics Engineers
Volume
3
First page number:
1534
Last page number:
1537
Abstract
The Sahara desert includes large expanses of sand dunes called ergs. These dunes are formed and constantly reshaped by prevailing winds. Previous study shows that Saharan ergs exhibit significant radar backscatter (sigmadeg) modulation with azimuth angle (Phi). We use sigmadeg measurements observed at various incidence angles (thetas) and Phi from the NASA scatterometer (NSCAT), the Seawinds scatterometer aboard QuikSCAT (QS-CAT), the ERS scatterometer (ESCAT) and the Tropical Rain Monitoring Mission's Precipitation Radar (TRMM-PR) to model the sigmadeg response from sand dunes. Sand dunes are modeled as a composite of tilted rough facets and small ripples. The dune fields are modeled as composed of many simple dunes. The sigmadeg measured by the scatterometer from (thetas, Phi) look direction is the sum of the returns from all the rough facets in the footprint. The model is applied to linear and transverse dunes with rough facets and Gaussian tilt distributions. The model results in a sigmadeg response similar to the NSCAT and ESCAT observations over areas of known dune types in the Sahara. This analysis gives a unique insight into scattering by large scale sand bedforms.
Keywords
Ergs; Geomorphology; Large scale sand bedforms; Remote sensing; Sahara desert; Sand dunes; Tropical Rain Monitoring Mission's Precipitation Radar
Disciplines
Geographic Information Sciences | Geology
Language
English
Repository Citation
Stephen, H.,
Long, D. G.
(2004).
Analysis of scatterometer observations of Saharan Ergs using a simple rough facet model.
2004 IEEE International Geoscience and Remote Sensing Symposium Proceedings, 3
1534-1537.
Institute of Electrical and Electronics Engineers.
http://dx.doi.org/10.1109/IGARSS.2004.1370604
Comments
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