Analyzing Accuracy Attributes of Landsat and Digital Terrain Tape Data in the Context of a Digital Geobase Information System

The major conclusions reached in this research effort are: 1) Landsat derived land cover classification data are, at present, a marginally accurate data source for county-level resource management requirements; and 2) the accuracy of standard product National Cartographic Information Center (NCIC) Digital Terrain Tape data appear to be questionable, again with respect to the information requirements of county level resource managers. Data representation accuracy has been analyzed for Landsat/MSS land cover and NCIC Digital Terrain Tape data. Lands at derived data correctly represented land cover in 71.5% of 200 randomly sampled grid cells verified against low-altitude photography. Only 61% of the sampled Digital Terrain Tape elevation values were within one-half of the contour interval (30.5 meters) on a 1:24,000 scale topographic map. The analysis here has been specifically designed around a digital, fixed-grid geobase information system. System attributes were oriented towards county level resource management usage. Results from this study indicate that for the geographic area and objectives of this research: 1) Landsat classification data are suitable as a first stage sample of land cover for county level resource management assessments; and 2) Digital Terrain tape data are inaccurate in portraying absolute elevations, but may be effective in supplying derived graphic or terrain data products, as well as in supplying additional channels of data for the land cover classification procedure