How large is the North American Datum of 1927 (NAD 27) to NAD 83 shift?
Within the conterminous 48 states, the North American Datum of 1927 (NAD 27) to the North American Datum of 1983 (NAD 83) shift of the latitude/longitude graticule (lines showing parallels of latitude and meridians of longitude for the earth) is in the range of 10-100 ground meters. Changes to UTM values are generally larger, around 200 meters, and changes for other coordinate systems are different.
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Related
Why are USGS historical topographic maps referenced to outdated datums?
How are different map projections used?
Why are the NAD 83 position values so far from the NAD 27 values? Were the old coordinates wrong?
The Revolution in Mapping at the U.S. Geological Survey
by Susan P. Benjamin, Research Geographer
The Revolution in Mapping at the U.S. Geological Survey
by Susan P. Benjamin, Research Geographer
Two topographers working with an alidade and plane table. The man on the right is believed to be Roland Whitman Burchard, who was the topographer for the USGS Grand Canyon Expedition of 1923. Author Lewis Freeman described Burchard as a man of "powerful physique, great endurance, and a cool, steady hand."
Two topographers working with an alidade and plane table. The man on the right is believed to be Roland Whitman Burchard, who was the topographer for the USGS Grand Canyon Expedition of 1923. Author Lewis Freeman described Burchard as a man of "powerful physique, great endurance, and a cool, steady hand."
Related
Why are USGS historical topographic maps referenced to outdated datums?
How are different map projections used?
Why are the NAD 83 position values so far from the NAD 27 values? Were the old coordinates wrong?
The Revolution in Mapping at the U.S. Geological Survey
by Susan P. Benjamin, Research Geographer
The Revolution in Mapping at the U.S. Geological Survey
by Susan P. Benjamin, Research Geographer
Two topographers working with an alidade and plane table. The man on the right is believed to be Roland Whitman Burchard, who was the topographer for the USGS Grand Canyon Expedition of 1923. Author Lewis Freeman described Burchard as a man of "powerful physique, great endurance, and a cool, steady hand."
Two topographers working with an alidade and plane table. The man on the right is believed to be Roland Whitman Burchard, who was the topographer for the USGS Grand Canyon Expedition of 1923. Author Lewis Freeman described Burchard as a man of "powerful physique, great endurance, and a cool, steady hand."