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Terrain Differences
rfSoftware products currently
use 3 different terrain databases: 30-second data from the FCC, 30-second data from
the GLOBE (Global
Land One-km Base Elevation) project and 3-second data from
the USGS. Below is a sample of each from the Boston/Cape
Cod area shown at 1:1,000,000 scale. In rfProfiler
Light, you don't see the terrain in this form, but seeing it this way will give
you a better sense of the differences.
30-second FCC:
The primary limiting factor in this data is its 10-meter vertical resolution. Notice that
much of the low-lying terrain registers as 0 meters elevation.
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30-second GLOBE:
The GLOBE data has 1 meter vertical resolution. Notice the greater degree of variation
compared to the FCC data.
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3-second USGS:
3-second terrain data is 100 times denser (10 times in each direction) than the
30-second data.
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