Detecting Small-scale Topographic Changes and Relict Geomorphic Features on Barrier Islands using SAR.
Remote Sensing Data
Data Acquisition
One of the more recent sensors to be used for remote sensing is Synthetic Aperture Radar (SAR). SAR can be used for classification of
terrestrial environments. Measurements of the SAR backscattering coefficient can be related to topography, geology, soil moisture and salinity, and vegetation density and structure. The focus of this work is the modeling of the SAR backscatter
coefficient for coastal environments. Fully polarametric SAR data in C, L, and P bands as well as the fixed-baseline interferometric SAR (TOPSAR) were acquired in April 1995 and June 1996. The data were acquired to detect topographic change and relict geomorphic features on the islands and to map the coastal wetlands.
Data Analysis
An initial study of the AIRSAR data was to identify and map herbaceous coastal wetlands. Our testsite on Bolivar Peninsula contains several environmental units including salt marsh, vegetated upland flats, and an intermediate transition zone. These regions often have maximum elevations of only five feet above sea level, so slight variations in elevation can have a great impact on determining the species of vegetation which are found there.
Each of these
sub-environments have distinct vegetation cover, soil texture, and soil salinity. These highly vegetated areas make it difficult to apply empirical surface models to represent the backscatter which is received by the AIRSAR. However, discrete
scattering models can be fit to the coastal wetland site on Bolivar Peninsula. These models provide some insight into the dominant scattering
mechanisms, and should aid in mapping of coastal wetlands.
Further Reading on Vegetation Modeling, : "Modeling Wetland Vegetation Using Polarimetric SAR" C. Slatton, M. Crawford, J. Gibeaut, R. Gutierrez
For More Information, contact Clint Slatton, Center For Space Research
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Last Modified: Tue Sept 14, 1999
CSR/TSGC Team Web
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