Roads driven

Base map from the United States Census Bureau

Airports visited

Base map from the National Atlas

Road data is in the form of LineStrings in KML harvested from Google Maps. The airport locations are from the OpenFlights Airports Database.

Drawing on a map requires a conversion from geographic coordinates to bitmap coordinates. Maps produced by both the Census Bureau and the USGS (such as the two maps above) use the Albers projection. After specifying the two standard parallels and the central meridian, the map geometry can be determined from two control points. These are easily obtained by writing down the pixel and longitude/latitude coordinates of two prominent points.