For years, cartographers (map makers) were faced with a challenge: how can they accurately depict a round planet Earth on a flat piece of paper? That was not a problem for short distances, but when the early explorers started to travel around the world, that became a problem. Their maps were flat but the world wasn't, and therein lies the problem.
Fast forward several hundred years to the 21st century as we fly around the world and have the same issues.
It's easy to figure out the route for a flight from New York to Chicago, go west. Miami to Boston is pretty easy too, go north. But what about a longer flight, such as Los Angeles to Hong Kong? The route may not be as obvious as it seems. When looking at a flat piece of paper, it's not easy to determine the great circle route between two locations. What is a great circle route? Answers.com defines it as "A segment of such a circle representing the shortest distance between two terrestrial points."
I have found a fabulous website that can help, Great Circle Mapper (
http://gc.kls2.com/), where you can enter your itinerary and quickly get a map showing the great circle route that you would follow on that trip.
The main page of Great Circle Mapper features an easy-to-use interface.
When you get to the front page, you enter the route that you are interested in. You can enter it using the airport abbreviation (Chicago O'Hare = ORD) or you can use the name of the city. If the city has more than one airport, you will get a list of the airports in that area and can select the appropriate one.
The itinerary I have entered above is Dallas-New York-Chicago-Dallas (DFW-JFK-ORD-DFW).
The map of the DFW-JFK-ORD-DFW route.
Great Circle Mapper provided the map above, showing the route, the mileage for each leg, and the initial heading that the aircraft will take. Is this the exact route the flight will take? No. Weather problems and Air Traffic Control issues could send you on another path, but you do get a pretty good idea of what the ideal route is.
As I mentioned, this itinerary does not cover a very great distance, so you could probably draw this same map route on a map of the United States. Great Circle Mapper shines however on long-distance itineraries. Let's look at a long-distance flight: Chicago to Frankfurt.
Chicago to Frankfurt route
The map above shows two different routes. The one in black (which I added) is the straight line route that I would draw if doing this on a flat map. The path in red is the great circle route that Great Circle Mapper has drawn. It is a much shorter route than the one in black, although it may not look it on a flat map.
Dallas to Tokyo route
The difference between the great circle route and a straight line on a flat map is even more pronounced as the flight gets longer. Here is the route from Dallas to Tokyo. If I were to draw this on a flat map, I probably would not have the flight going near Alaska, but that is indeed the shortest route.
Los Angeles to Frankfurt route
The curvature of the route is very evident on a trip from Los Angeles to Frankfurt.
Great Circle Mapper provides more information that just the route. If you click on the name of an airport, you'll get an a page with a great amount of information about that airport, including location (exact latitude and longitude), elevation, time, weather, an airport chart, and number and length of the runways.
Dallas/Fort Worth Airport information
Here is the information for the Dallas/Fort Worth (DFW) airport, where the longest runway is 13.402 feet (4,085 meters).
Great Circle Mapper has one other feature that I find interesting: What is the most distant place on earth from that airport?
The most distant location from Dallas/Fort Worth Airport.
From Dallas/Fort Worth Airport, the most distant location is Plaine Corail, on Rodrigues Island, in Mauritius, 10,930 miles away. The most distant location from Logan Airport in Boston is Margaret River, Western Australia, Australia, 11,763 miles away. This feature could come in handy the next time your co-worker says they would really like to get away to some place distant, or you can use it to win a bar bet.
I enjoy knowing the route my flight will take so I always visit this before I take a trip. Give Great Circle Mapper a try, it's a great travel tool.
When you visit, see if you can get the answer to this question: American Airlines offers nonstop service from Chicago (ORD) to New Delhi (DEL). Continental offers nonstop service from Newark (EWR) to Singapore (SIN). Let Great Circle Mapper draw these routes for you, and see if you can tell me what makes them both so unique. I'll post the answer next week.
Labels: Great Circle Mapper
