One kilometer elevation data, downloaded from the United States Geological Survey EROS
Data Center, were processed for use in MAGIS using the open source
Geographic Resources Analysis
Support System (GRASS).
Modern Political Districts, National Capitals, and Modern Major Cities vector data layers
were generated using ArcGIS™ and the "Countries 2004" and
"Cities" data from the ArcGIS™, ESRI® Data & Maps Media Kit
"World, Europe, Canada, and Mexico" CD. All other vector data layers were
manually created using ArcGIS™.
Ninety meter elevation data and vector water body data obtained by NASA's
Shuttle Radar Topography
Mission (SRTM) were purchased on DVD from the United
States Geological Survey and processed using ArcGIS™.