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ERDC TR-05-1

Angle Mapper (SAM) routine within ENVI. This function assigns each indi-

vidual pixel to a class based on the calculated angle, measured as the arc dis-

tance, between that pixel's DN values (using all 14 bands) and each of the mean

vectors of the training signatures. The maximum spectral angle is user-defined

the SAM algorithm in the southern mosaic, a spectral angle of 0.08 radians

(~ 4.58) was chosen. The 14-row, 1-column vector for the first pixel in the

image (i.e., the unknown spectrum) and the 14-row, 1-column mean vector for a

single reference spectrum are used as inputs into the following equation.