U.S. Geological Survey, 1999, Digital representation of "Atlas of United States Trees" by Elbert L. Little, Jr..Online Links:
This is a Vector data set. It contains the following vector data types (SDTS terminology):
Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.01. Longitudes are given to the nearest 0.01. Latitude and longitude values are specified in Decimal degrees.
The horizontal datum used is North American Datum of 1927.
The ellipsoid used is Clarke 1866.
The semi-major axis of the ellipsoid used is 6378206.4.
The flattening of the ellipsoid used is 1/294.98.
Robert S. Thompson
U.S. Geological Survey
Geologist
Denver Federal Center
MS 980, Box 25046
Denver, Colorado 80225-0046
USA
303-236-5347 (voice)
303-236-5349 (FAX)
rthompson@usgs.gov
To create a digital representation of the vegetation range maps published in "Atlas of United States Trees" by Elbert L. Little, Jr.
Little, Elbert L., Jr., 1971, Atlas of United States Trees, Volume 1: Conifers and Important Hardwoods.
Little, Elbert L., Jr., 1976, Atlas of United States Trees, Volume 3: Minor Western Hardwoods.
Little, Elbert L., Jr., 1977, Atlas of United States Trees, Volume 4: Minor Eastern Hardwoods.
The single user-defined attribute ("code") has an enumerated domain (values of 0 or 1 only), so numerical measures of accuracy are not applicable. The data sets were checked for attribute accuracy by visually comparing color-coded plots of each dataset with the source maps.
At least 90% of the points tested on hard copy printout are within 1/50 inch (0.5mm) of the source data.
All polygons on the printed source maps are represented in the digital coverages.
In some instances, data for the United States portions of the maps were derived from source maps at 1:10,000,000 scale and the portions outside the United States were derived from sources at approximately 1:27,000,000 scale. The coverages were checked for node, intersection, and duplication errors and corrected when necessary. All polygons were snapped closed at nodes.
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints: None
U.S. Geological Survey
c/o Randall Schumann
Denver Federal Center
MS 980, Box 25046
Denver, CO 80225-0046
USA
(303) 236-1525 (voice)
(303) 236-5349 (FAX)
rschumann@usgs.gov
Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data.The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials.
Data format: | ArcView Shapefile |
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Network links: |
<http://esp.cr.usgs.gov/data/atlas/little/> |
U.S. Geological Survey
c/o Sharon Smith
GIS Computer Specialist
Denver Federal Center
MS 980, Box 25046
Denver, Colorado 80225-0046
USA
303-236-4610 (voice)
303-236-5349 (FAX)
ssmith@climate.cr.usgs.gov