Skip to content


Switch branches/tags

Latest commit


Git stats


Failed to load latest commit information.
Latest commit message
Commit time

Ptolemy Layer for Google Earth (ptolemy)

Claudius Ptolemy, a famous ancient Hellenic geographer and astronomer from Alexandria, Egypt, provided coordinates of 6000+ objects of the known world (oikoumen?) in his classical Geography [1] and supplemented them with many useful descriptions and names of tribes that lived nearby. In essence, Ptolemy provided the earliest surviving world “map” described in terms of longitudes, latitudes, and projections. However, this map containing valuable data on ancient cities, villages, marts, harbors, rivers, etc. is difficult to visualize, primarily due to major distortions apparent when the Ptolemaic coordinates are compared to modern ones of the numerous objects identified with certainty. Thankfully, those objects can serve us as reference points in our effort to map out the places which (to the best of our understanding) Ptolemy is talking about, using modern coordinates.

This is part of a research project at Purdue. It is also hosted as a [project at Purdue University Research Repository (PURR)] ( "Ptolemy Layer for Google Earth"). We are also building a website for the project, but it's pretty bare at the moment. We hope to remedy this in the near future.

Please note that the project is really just getting started, so what you see here right now is very unstable and should be considered as under construction. We are making it available early to collaborate within the project team but also to make our work in progress visible to anyone else who may share an interest.

Our paper called A Mathematical Method for Visualizing Ptolemy’s India in Modern GIS Tools explains our initial work in this area and has been accepted to the upcoming
10th Jubilee Conference + Workshop "Digital Approaches to Cartographic Heritage" in Corfu, Greece.

Also, note that most of the scripts reference data files that are not yet releasable. This will be remedied as soon as possible where possible. We are primarily using McCrindle's Ancient India as Described by Ptolemy and Stuckelberger and Grasshoff. The latter in particular comes with a database we are relying on heavily to prime our initial model. We are also looking at Stevenson to a degree, but realize it comes with problems. If you need help on this in the meantime please contact myself, Prof. Gusev, or Dr. Papapanagiotou.


Ptolemy Layer for Google Earth







No releases published


No packages published