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Full-Text Articles in Social and Behavioral Sciences
Microwave Backscatter Modeling Of Erg Surfaces In The Sahara Desert, Haroon Stephen, David G. Long
Microwave Backscatter Modeling Of Erg Surfaces In The Sahara Desert, Haroon Stephen, David G. Long
Public Policy and Leadership Faculty Publications
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 (σ°) modulation with azimuth angle (f). We use σ° measurements observed at various incidence angles and f from the NASA Scatterometer (NSCAT), the SeaWinds scatterometer, the ERS scatterometer (ESCAT), and the Tropical Rainfall Measuring Mission's Precipitation Radar to model the σ° response from sand dunes. Observations reveal a characteristic relationship between the backscatter modulation and the dune type, i.e., the number and orientation of the dune slopes. Sand dunes …
Modeling Microwave Emissions Of Erg Surfaces In The Sahara Desert, Haroon Stephen, David G. Long
Modeling Microwave Emissions Of Erg Surfaces In The Sahara Desert, Haroon Stephen, David G. Long
Public Policy and Leadership Faculty Publications
Sand seas (ergs) of the Sahara are the most dynamic parts of the desert. Aeolian erosion, transportation, and deposition continue to reshape the surface of the ergs. The large-scale features (dunes) of these bedforms reflect the characteristics of the sand and the long-term wind. Radiometric emissions from the ergs have strong dependence on the surface geometry. We model the erg surface as composed of tilted rough facets. Each facet is characterized by a tilt distribution dependent upon the surface roughness of the facet. The radiometric temperature (T(b)) of ergs is then the weighted sum of the T(b) from all the …