The Archaeogeodesy Pages ©1997-2012 by James Q. Jacobs
Archaeogeodesy can be defined as that area of study encompassing prehistoric and ancient place determination, navigation (on land or water), point positioning, measure and representation of the earth, geodynamic phenomena, and the applied astronomy. Archaeogeodesy, by combining fundamental astronomy, geodetic knowledge, applied mathematics, accurate positional data and archaeology, presents a methodology for investigating the architecture, placements, spatial properties, relationships and arrangements of prehistoric sites and monuments. As a new area of inquiry, archaeogeodesy presents unique avenues of assessing ancient understandings of geography, of place, and of the earth and the cosmos as evidenced by archaeological remains.

Archaeogeodesy is the field of study I proposed in 1991 upon publishing Site-to-Site Relationships of Monumental Prehistoric Sites of North America. In 1992, I wrote Archaeogeodesy, A Key to Prehistory, discussing basic concepts and presenting study findings to illustrate fundamental ideas. Rewrittten and enlarged, the online version is now a series of four articles. Above is the first paragraph.

Since 1992, GPS technology has become readily available and affordable. Coordinates I once scaled from maps are being refined to near-meter accuracy. The GPS system also utilizes a global coordinate system, WGS84. Previous national systems utilized distinct reference spheres and required corrections. Current technology has facilitated moving beyond approximate coordinates and consequent preliminary study results. Therefore, more findings are now incorporated in these pages.

Newark Archaeogeodesy
Assessing Evidence of Geospatial Intelligence in the Americas


Mound Builders of the
Eastern Woodlands Photo Galleries

Temporal Epoch Calculations

Archaeogeodetic Excel Applications with Site Coordinates
If utilizing the software and data I present, the degree of accuracy inherent in the coordinates must be considered. Unless coordinates are GPS determined, accuracy is approximate. Hopefully, distribution of these tools will stimulate others to acquire GPS coordinates. I welcome contributions of GPS data, and thank those who have added to the site data.

Archaeogeodetic Excel calculator: arc distances and bearings for three sites, with mounds, pyramids, and sites worldwide.
Arc distances and bearings
for three sites, with some Neolithic
monuments of northeastern Europe.


for Google Earth.

The placemarks files
integrate with the
applications, using the
same coordinates and
site code terms,
and with the
Photo Galleries,
linking photos.

Articles and References

The Geodesy Page presents definitions, figure of the earth formulas,
and other useful information about geodesy.

The Chaco Meridian. Big Horn Medicine Wheel, Mt. Wilson, Aztec Ruin, Chaco Canyon,
the Mimbres Valley, and Casas Grandes in Northern Mexico are all situated
on an approximate north-south line near the 108th meridian.

Formulas, constants, and definitions employed in the Archaeogeodesy Pages



Epoch Calc temporal variation in astronomy constants, obliquity of the ecliptic, eclipses....

Watching Eclipses, Counting Orbits PowerPoint with AeGeo code.

Eclipses, Cosmic Clockwork of the Ancients    |    Eclipse Calc, an eclipse calculator

Ancient Astronomy, Integers, Great Ratios, and Aristarchus

Stonehenge and Astronomy    |    Stonehenge and Pi

Preliminary Archaeogeodesy Study Results
for Three Major Neolithic Complexes

Thornborough Henges and the Ure-Swale Monuments
Assessing Evidence of Geospatial Intelligence in the Neolithic

The Ur and Harran Latitudes, and Göbekli Tepe

Archaeogeodesy Studies

  • 1991. Study Notes: Site-to-Site Relationships of Monumental Prehistoric Sites of North America.
  • 1992. Study Notes: Site-to-Site Relationships of Prehistoric Monuments.
  • 1992. Archaeogeodesy, a Key to Prehistory.
  • 1993. Archaeogeodesy Study Notes.
  • 1993. ArchaeoGeodesy, the Software.
  • 1996. Archaeogeography Studies.
  • 1996. Monks Mound and Secular Polar Motion.
  • 1997. First publication of this web site.
  • 2000. The Possible Geodetic Properties and Relationships of Neolithic Monuments of the British Isles, Preliminary Results.
    • "Longitude is an easier problem to resolve on land than at sea, and may have been accomplished with a lunar calendar and astronomic observations over an extended period of time... ""It is very probable that the builders of Avebury and the nearby large henges were conscious of their position on a round earth."
    • "... results suggest the possibility that geodetic knowledge was sufficiently advaned to include the ellipsoidal form of the earth, determination of longitude, and precise positioning of monuments in relation to each other across great distances and on opposite sides of the Irish Sea. Although the amount of evidence so far revealed is not a resounding affirmation of this view, enough evidence has been brought to light to conclude that the possibility deserves further study."
  • 2001. Possible Geodetic Properties and Relationships of Some Monumental Earthworks in the Middle Ohio Valley.
    • " The Newark Octagon and Marietta Square ratio of arc distance to longitude difference, the azimuth of the Newark Octagon, and the bearings between Newark Circle and the Octagon Circle infer precise understanding of the mathematical ratio of latitude to longitude. "
    • "I conclude that the builders of the Middle Ohio earthworks understood aspects of geodesy, including accurate astronomical knowledge, knowledge of the scale and shape of the earth, knowledge of their location on the earth, and how to place find and point position."
  • 2002. Science in Prehispanic Mesoamerica
Marietta, Ohio, Quadranau Mound. Fall 2005.
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