Eye-catching maps are a great way to present an airline’s network, opportunities and aircraft movements, as well as our own journeys. I often include them in reports and proposals for airlines and airline suppliers. As with all graphics, choosing the right map can make the difference between good and poor presentation. In this article I will be explaining how to make the most of the Great Circle Mapper (GCM) tool to create the coolest possible maps.
How the Great Circle Mapper works
Simply enter either an IATA airport code (e.g. LHR), an ICAO airport code (e.g. EGLL) or co-ordinates (e.g. 51.45N,0.45W) and press the map button – Heathrow Airport in the south-east of Great Britain will appear. You can join a pair to produce the shortest route between the two (e.g. LHR-NCL, EGLL-NCL, 51.45N,0.45W-NCL). My understanding is that the airports are reasonably accurate but the co-ordinates are off a bit.
Types of map
You can choose one of four projections by clicking “map conf” once you have generated a basic map. The options are:
Rectangular: the standard Mercator projection – Africa and South America are too small and Greenland is too large, but everywhere is the right shape
Orthographic: a hemisphere centred on the first point you enter – half the world is missing but everywhere is the right size and shape and the shortest distance between the centre and any other point is a straight line
Polar-aspect orthographic: either the northern or southern hemisphere, centred on the relevant pole – tends to show the north pole if you use both northern and southern hemisphere locations
Azimuthal equidistant: this map shows the whole world projected as a circle – the further out you get the more shapes are distorted
Rectangular map applications
Here is a rectangular map showing everywhere that British Airways have taken me from Heathrow in recent years. Mainly business, with one or two holidays. It all looks very impressive at first glance, but it is rather cluttered – especially in Europe.
I think that the rectangular map is best for regional maps like this one, which nicely shows all my BA travels in Europe without the clutter of longhaul.
Since the paths are not very interesting, simply straight lines from Heathrow, we can make the map easier to read by just showing the airports.
Orthographic map applications
Take my BA longhaul flights. The rectangular map is much less cluttered than before because we have taken away the European routes.
Selecting the orthographic projection, the routes are all straight lines.
Although they are all straight lines, due to the large distances between London and the other cities, that Singapore is off-chart and that Asian cities are close to the edge, removing the paths does not make the map easier to read.
But by making two orthographic maps I can present my travels much more clearly without showing any paths. It allows me to add my mission to work with Air Vanuatu (VLI) via SYD, which did not fly on BA, without making the map too messy. I made these by centring the maps at 0N,90E and 0N,90W.
Notice how these maps also show clearly the large number of places I have not been.
Polar-aspect orthographic map applications
This is the map where some of the coolest paths appear. For example, I can compare how close I get to the pole on my trips to China with my trips to America. It shows clearly how much further it is to get to China than America’s Atlantic coast.
Adding 1,000 mile, 2,000 mile and 3,000 mile ranges around the north pole (90N,0W) shows that I go much further north on the China trips too because I cross the 2,000 mile line.
PRO TIP: placing ranges around one point produces shading – to get the clear black lines, place the relevant ranges and add a one mile range around another point on the map (e.g. 1000mi@90n,0w,2000mi@90n,0w,3000mi@90n,0w,1mi@lhr).
The standard orthographic projection is inelegant.
Azimuthal equidistant map applications
The azimuthal equidistant map should be used with caution. Showing my longhaul BA flights is not bad for distance and geography across most places, but notice how distorted Australia, New Zealand and Antarctica are.
Adding my mission to Vanuatu, the three hour 737 flight from SYD to VLI looks far too long.
The best way to use the azimuthal equidistant projection is to centre on the north pole. This ‘surrounds’ the map with Antarctica but most other places are well shown, although VLI is still too far from SYD.
This projection works really well for round-the-world trips across both hemispheres, with a more accurate reflection of distance and geography than any other configuration until you start flying a long way south. Projections centred on the south pole look odd.
Notice how inelegant the rectangular projection is in comparison.
And there’s more…
That’s not all the GCM can do. There are labels, indicators of where aircraft are allowed to fly (ETOPS), the ability to set units for distances along paths and airport information. Enjoy playing around with it. And don’t forget to show me any cool maps you make!
Oliver AT ransonpricing DOT com