Abstract
A new adjustment of the geodetic control networks in North America has been completed, resulting in a new continental datum—the North American Datum of 1983 (NAD 83).
The establishment ofNAD 83 was the result of an international project involving the National Geodetic Survey of the United States, the Geodetic Survey of Canada, and the Danish Geodetic Institute (responsible for surveying in Greenland). The geodetic data in Mexico and Central America were collected by the Inter American Geodetic Survey and validated by the Defense Mapping Agency Hydrographic/Topographic Center.
The fundamental task ofNAD 83 was a simultaneous least squares adjustment involving 266,436 stations in the United States, Canada, Mexico, and Central America. The networks in Greenland, Hawaii, and the Caribbean islands were connected to the datum through Doppler satellite and Very Long Baseline Interferometry (VLBI) observations.
The computations were performed with respect to the ellipsoid of the Geodetic Reference System of 1980. The ellipsoid is positioned in such a way as to be geocentric, and its axes are oriented by the Bureau International de l'Heure Terrestrial System of 1984.
The mathematical model for theNAD readjustment was the height-controlled three-dimensional system. The least squares adjustment involved 1,785,772 observations and 928,735 unknowns. The formation and solution of the normal equations were carried out according to the Helmert block method.
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References
D.E. ALGER: Implementation of the National Geodetic Survey data base. Proceedings of the Second International Symposium on Problems Related to the Redefinition of the North American Geodetic Networks. Arlington, Va., April 24–28, pp. 247–257. National Geodetic Information Branch, NOAA, Rockville, ME), 20852, 1978.
J.D. BOSSLER: Status of the New Adjustment in the United States. Proceedings of the Second International Symposium on Problems Related to the Redefinition of the North American Geodetic Networks, pp. 31–39, Arlington, Virginia, April 24–28. National Geodetic Information Branch, NOAA, Rockville, Maryland 20852, 1978.
Danish Geodetic Institute: Proceedings of the International Symposium Management of Geodetic Data, Copenhagen, August 24-26. Published as Report No. 55 of the Danish Geodetic Institute, Copenhagen, 1981.
Defense Mapping Agency: Report of the DoD Geoceiver Test Program. DMA Report 0001, 1972.
W.T. DEWHURST. A practical approach to datum transformations between North American Datum of 1927 and North American Datum of 1983. NOAA Technical Memorandum NOS NGS 50, October, 1989. National Geodetic Information Branch NOAA, Rockville MD. 20852.
R.J. FURY: Prediction of deflections of the vertical by gravimetric methods. NOAA Technical Report NOS 103 NGS 28. National Geodetic Information Branch NOAA, Rockville, Maryland 20852, 25 p., 1984.
P. MEISSL: A priori prediction of roundoff error accumulation in the solution of a super-large geodetic normal equation system. NOAA Professional Paper No. 12. National Geodetic Information Branch, NOAA, Rockville, Maryland, 1980.
H. MORITZ: Geodetic Reference System 1980. Bulletin Géodésique, Vol. 54, No. 3, 1980.
National Geodetic Survey: Proceedings of the Second International Symposium on Problems Related to the Redefinition of North American Geodetic Networks, Arlington, Virginia, April 24–28. National Geodetic Information Branch, NOAA, Rockville, Maryland, 1978.
K. PODER and C.C. TSCHERNING: Cholesky's method on a computer. Internal Report No. 8. The Danish Geodetic Institute, Copenhagen, 1973.
C.R. SCHWARZ: TRAV10 Horizontal Network Adjustment Program NOAA Technical Memorandum NOS NGS-12. National Geodetic Information Branch, NOAA, Rockville, Maryland, 1978.
C.R. SCHWARZ (ed.): The North American Datum of 1983. NOAA Professional Paper NOS 2, National Geodetic Information Branch, NOAA, Rockville, Maryland, 1989.
R.A. SNAY: Reducing the Profile of Sparse Symmetric Matrices. Bulletin Géodésique, Vol. 50, No.4, pp. 341–352, 1976.
R.A. SNAY, M.W. CLINE and E.L. TIMMERMAN: Project REDEAM: Models for historical deformation in tectonically active regions of the United States. NOAA Technical /Teport, NOS 125 NGS 42, 76 p., National Geodetic Information Branch, NOAA, Rockville, Maryland 1987.
R.R. STEEVES: Mathematical Models for Use in the Readjustment of the North American Geodetic Networks. Geodetic Survey of Canada Technical Report No. 1, Ottawa, 1984.
W.E. STRANGE and L.D. HOTHEM: The National Geodetic Survey Doppler Satellite Positioning Program. Proceedings of the International Geodetic Symposium on Satellite Doppler Positioning. October, 1976.
W.E. STRANGE and R.J. FURY: Computation of deflections of the vertical in Support of the readjustment of the North American Datum. Proceedings of the International Symposium on Optimization of Design and Computation of Control Networks Sopron, Hungary, 1977
U.S. Geological Survey: North American Datum of 1983 map data conversion tables. U.S. Geological Survey Bulletin 1875, Vol. A (Eastern U.S.), B (Western U.S,), and C (Alaska), 1989
University of New Brunswick: Proceedings of the International Symposium on Problems Related to the Redefinition of the North American Geodetic Networks. University of New Brunswick, Fredericton, May 20 to 25. Reprinted from The Canadian Surveyor, Vol. 28.. No. 5, pp, 436— 749, December 1974.
T. VINCENTY and B.R. BOWRING: Application of three-dimensional geodesy to adjustments of horizontal networks. NOAA Technical Memorandum /VOS NGS-13, National Geodetic Information Branch, NOAA, Rockville, Maryland, 1978.
T. VINCENTY: Determination of North American Datum of 1983 coordinates of map corners (second prediction). NOAA Technical Memorandum NOS NGS–16. National Geodetic Information Branch, NOAA, Rockville, Maryland,. 1979.
T. VINCENTY: Height-controlled three-dimensional adjustment of geodetic networks. Bulletin Géodésique, Vol. 54, No. 1, 1980.
T. VINCENTY: Methods of adjusting space systems data and terrestrial measurements. Bulletin Géodésique, Vol. 56, No. 3, 1978.
C.A. WHITTEN: Adjustment of the European Triangulation. Bulletin Géodésique, No. 24, 1952.
H. WOLF: The Helmert block method–Its origin and development, in Proceedings of the Second International Symposium on Problems Related to the Redefinition of the North American Geodetic Networks, Arlington, Virginia, April 24–28, pp. 319–326. National Geodetic Information Branch, NOAA, Rockville, Maryland, 1978.
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[Authors' note:This article is a condensation of the final report of the NAD 83 project. The full report (Schwarz,1989) contains a more complete discussion of all the topics.]
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Schwarz, C.R., Wade, E.B. The North American datum of 1983: Project methodology and execution. Bull. Geodesique 64, 28–62 (1990). https://doi.org/10.1007/BF02530614
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DOI: https://doi.org/10.1007/BF02530614