4.2.5. Classification of other impervious surfaces
As stated earlier, the category of other impervious surfaces
includes roads, driveways, sidewalks, and parking lots. The expert
system rule that was employed for the extraction of roads is the
reverse of the approach employed above for identifying buildings.
Hence, the selected bands for the feature space include mean of the
original band 1, ratio of PCA band 3, and NDVI image. We also used the
same scale-level that we used for the building (scale parameter=25).
The expert system rule employed can be described as
(1) Ratio PCA band 3 DN values between 0.45 and 0.58 (and)
(2) Mean band 1 DN valuesb390 (and)
(3) NDVI valuesN0.1