Featured Map for 13 September 2012:
Great Circle Mapper's Sweet 16th

Today is the Great Circle Mapper's 16th birthday, counting from its public announcement.

Airlines (real and virtual), charter operators, aircraft manufacturers, frequent fliers, teachers and their students, militaries, search and rescue personnel, and others all find the maps useful. Some poeple simply have fun with the maps.

Lots of maps: last month, for the first time in a single month, the Great Circle Mapper generated over five million maps.

The maps wouldn't be very useful, however, without the location database which allows users to enter SFO-LHR instead of N37.618972 W122.374888-N51.477500 W0.461388. Building and maintaining this database is an ongoing process, both to incorporate changes (new airports open, airports close, runway changes subtly alter the location of an airport) and to correct and improve data.

Today's Featured Map depicts the current database of 34,406 airfields. 85.7% of these are based on high-quality data and are shown in green. The 14.3% in red use low-quality data, which is imprecise and may be inaccurate. Gradually, more of this map is turning green.

Many thanks to everyone who has contributed improvements!

References and additional information:

• Great Circle mapper; sci.aeronautics.airliners WWW page news
• Great circle flight path display (24 September 1996)
• Featured Maps: The First (14 January 2010)
• Featured Maps: Great Circle Mapper 14th Anniversary (13 September 2010)
• Featured Maps: Great Circle Mapper 15th Anniversary (13 September 2011)