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Taking the long way to Asia

By: Alexander Ridgeway

As a Systems Engineer in the Singapore office, I travel back and forth from the  United States to Singapore quite often. During trips, I am surprised by the number of times I receive this question, “Why are we flying upwards towards Alaska and Japan to get to Singapore?,” “Why aren’t we flying direct to Singapore?,” or a veiled uncertainty with the comment, “Let’s meet half-way to Asia in Hawaii!"

I have to reassure my family, friends, and ‘row-mates’ that we are taking the most direct route. The main reason why people have these misconceptions is because of maps. The surface of a sphere (3D) cannot be represented on a plane (2D) without some sort of distortion. This plane , not this  . These distortions fool with our concept of distance when looking at maps and one route could look shorter but in reality, it is not. Here is a great video on why maps are wrong: https://www.youtube.com/watch?v=kIID5FDi2JQ.

To map projections, I use STK, which has both a globe and a map that share data inputs. STK has different projections to use, including Mercator, Equidistant Cylindrical, Azimuthal Equidistant, Miller, and others. The default  projection is Equidistant Cylindrical, which I show below. 

I added areas targets of the same size at different latitudes. You can see the difference between the 3D and 2D visualization. Both are displaying the same data, which is a circular area target of a radius of 300 km. Due to the 2D map projection, we can see at the higher latitudes that the distortion is much larger. 3D visualization provides a clear image of area targets of the same size with minor distortion due to the viewing angle, but overall the circular area targets maintain their size and shape.

Now, let's model the two vehicle routes, HowPeopleThinkWeFly and HowWeActuallyFly, in STK. We can see that in the 2D map projection, HowPeopleThinkWeFly appears to be the shortest route. It looks like the most direct route and if I were to physically measure it on the map with a bit of string, it would be a shorter distance than HowWeActuallyFly. However, the 2D projection fools us here. If we take a look at the 3D globe, we can clearly see that HowWeActuallyFly is the most direct way.

If we analyze this further using the STK Great Arc propagator, we will see the difference in total flight time and total distance traveled for both vehicles going 800 km/hr. Now we know that the pilot is flying the most direct route to get us from US to Singapore and the time saved is a nice perk for the desperate travelers who can’t sleep and have watched all the movies.

  Total Flight Time Total Distance
HowPeopleThinkWeFly ~18.029 hrs ~14400
HowWeActuallyFly ~17.145 hrs ~13690
Difference~ 0.884 hr = 53 min 710 km

I hope you found this useful and hope to see you in Singapore!

Posted: 7/30/2018 7:00:00 AM


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