To see how the spectral separation line coincides with the spatial
boundary between urban and rural, additional grey scales might be
introduced for pixels close to the separation line. The result is
shown in Fig. 4.
Pixels close to the separation line do indeed form 'fringe rings'
around the urban area, as could be expected, since on the rural/urban
boundary there will be many 'mixed' pixels. But close to the separa-
tion line there are also pixels belonging to the upper parts of the
agricultural and forest clusters, so that scattered parts of the
rural areas are now also shown on the maps that do not belong to the
urban fringe at all.
5. Comparison USEMAP — LANDSAT
5.1 General
When comparing the USEMAP results with the LANDSAT urban area, it is
important to realize the differences between the 2 sources, They are
summarized in the table below.
TABLE 2: Specifications of USEMAP and LANDSAT classifications
USEMAP LANDSAT
Date Oct. 1972 March 1973
Scale 1:10,000 -
Gridcell 50x83 m2 57x77 m2
Pixel (3x3 m2") 57x77 m2
Classification 65 classes 2 classes
Time 40 man-days 1-2 man-days
Area 4000 ha 6000 ha