2. Reference List   

 Datum development is not a trivial topic. Creating a model of the Earth is not a simple task. Consider the size of the Earth and what its surface is like. Its mass is not uniform nor static. It wobbles as it rotates and is affected by the varying gravitational pull of the Moon. Gravity pulls it in and centrifugal force pushes it out. All in all, quite a challenge. That's why we have geodisists - they eat this stuff up.

This topic summarizes the process, defines pertinent geodetic terms, and summarizes North American horizontal datum evolution. For more information, the following reference list is provided. All are available at the NGS website in its Publications Library (https://geodesy.noaa.gov/library/).  

• “North American Datum” National Academy of Sciences, 1971
• “North American Datum of 1983”, Charles R. Schwartz, Editor, NOAA Professional Paper NOS 2, Dec 1989
• "Geodetic Surveys in the United States, The Beginning And The Next One Hundred Years", Joseph F. Dracup, NOAA Sp Pub NOS NGS 05, 2007
• "The New Horizontal Control Datum for North America: NAD 83", Steven Vogel, NOAA Sp Pub NOS NGS 1, 1996