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Spectral Unmixing Applied to Desert Soils for the - Naval ...

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camp road endmembers, respectively. Figure 38, inset C shows a color composite of <strong>the</strong><br />

atmospherically corrected imagery from <strong>the</strong> f110512t01p00r07 data set. The image<br />

colors were chosen <strong>to</strong> enhance different surface materials in <strong>the</strong> image <strong>to</strong> makes sure <strong>the</strong><br />

endmembers were accurately identifying potential target material, particularly in <strong>the</strong><br />

creek areas where <strong>the</strong>re are significant quantities of vegetation (shown as red in inset C of<br />

Figure 38).<br />

The composites illustrate both <strong>the</strong> successes and failures of <strong>the</strong> endmembers, yet<br />

still seem <strong>to</strong> do <strong>the</strong> job of identifying <strong>the</strong> types of features being looked <strong>for</strong> based only on<br />

changes in spectra related <strong>to</strong> surface disturbances supplied by <strong>the</strong> ASD collected<br />

endmembers. In <strong>the</strong> color composites, <strong>the</strong> brightest pixels are associated with <strong>the</strong> largest<br />

percentage values, typically around 20%. These were generally associated as false<br />

positives, while <strong>the</strong> more muted pixels corresponded <strong>to</strong> lower ranges between 9 and 18%<br />

and were <strong>the</strong> most accurately identified pixels, as far as trail like features are concerned.<br />

Many of <strong>the</strong> endmembers yielded similar results but with higher concentrations in areas<br />

associated with <strong>the</strong> type of region <strong>the</strong> samples were collected from. For example, <strong>the</strong><br />

disturbed creek soil endmember had more successes and higher positive matches in areas<br />

where creeks and drainage basins were found.<br />

73

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