[Federal Register Volume 60, Number 157 (Tuesday, August 15, 1995)]
[Notices]
[Page 42146]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-19408]



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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[Docket No. 950728196-5196-01]


Use of the ``NAD 83/GWS 84'' Datum Tag on Mapping Products

AGENCY: Office of National Geodetic Survey, National Ocean Service, 
National Oceanic and Atmospheric Administration, Commerce.

ACTION: Notice.

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SUMMARY: The Office of National Geodetic Survey, redefined and 
readjusted the North American Datum of 1927 (NAD 27), creating the 
North American Datum of 1983 (NAD 83). The World Geodetic System of 
1984 (WGS 84) was defined by the Defense Mapping Agency (DMA). The 
interagency Federal Geodetic Control Subcommittee (FGCS) at its meeting 
on December 7, 1994, recommended that ``All maps and charts produced 
for North America, at scales of 1:5,000 or smaller, that are based on 
either the North American Datum of 1983 (NAD 83) or the World Geodetic 
System of 1984 (WGS 84), should have the horizontal datum labeled as 
NAD 83/WGS 84''.

SUPPLEMENTARY INFORMATION: The following supplementary information was 
reviewed by FGCS membership. A Federal Register notice published on 
June 29, 1979 (44 FR 37969), by the National Oceanic and Atmospheric 
Administration (NOAA) provided notification of the establishment of a 
new Datum (NAD 83) to which the geographic and plane coordinate values 
for the National Network of Horizontal Geodetic Control would be 
referenced. A Federal Register notice published on June 14, 1989 (54 FR 
25318), by NOAA affirmed NAD 83 as the official horizontal datum for 
all future U.S. surveying and mapping activities performed or financed 
by the Federal Government. Furthermore, this notice said that to the 
extent practicable and feasible, all Federal agencies using coordinate 
information should provide for an orderly transition to NAD 83.
    Both NAD 83 and WGS 84 were originally defined (in words) to be 
geocentric and oriented as the Bureau International de l'Heure (BIH) 
Terrestrial System. In principle, the three-dimensional coordinates of 
a single physical point should therefore be the same in both NAD 83 and 
WGS 84 systems; in practice, small differences are sometimes found. The 
original intent was that both systems would use the Geodetic Reference 
System of 1980 (GRS 80) as a reference ellipsoid. As it happened, the 
WGS 84 ellipsoid differs very slightly from GRS 80. The difference is 
0.0001 meters in the semi-minor axis.
    Effective January 2, 1994, the WGS 84 reference system was 
realigned to be compatible with the International Earth Rotation 
Service's Terrestrial Reference Frame (ITRF).

FOR FURTHER INFORMATION CONTACT: Mr. James E. Stem, N/CG11, SSMC3 
Station 9357, National Geodetic Survey, NOAA, Silver Spring, Maryland 
20910; telephone: (301) 713-3231, FAX: (301) 713-4176, Internet: 
[email protected].

    Dated: July 5, 1995.
W. Stanley Wilson,
Assistant Administrator, NOS.
[FR Doc. 95-19408 Filed 8-14-95; 8:45 am]
BILLING CODE 3510-08-M