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World Airports Voronoi (2014)

jasondavies.com

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Re: World Airports Voronoi (2014)

#91

Post by isostatic »

handelaar wrote: post #85
jasondavies wrote: post #75

Earlier quoted context omitted.

This is probably the most frequently asked question! The data is from here: http://ourairports.com/data/ I had to limit the number of airports displayed for performance reasons. I filtered the airport data so that only those airports with scheduled services and which are denoted "large" or "medium" are included (according to OurAirports), bringing the number down to 2,980.

Suppose that'll explain why there are at least three airports included in Ireland that have no scheduled services at all: the data's from nearly a decade ago

I am amused how airports like Lands End (which was grass runways only before 2014), and Chester(!!) made the cut. Plymouth closed in 2011

However that's all nitpicking, this is a pretty cool map, I'd never encountered Voronoi diagrams before.

Re: World Airports Voronoi (2014)

#92

Post by isostatic »

coin wrote: post #48
glup wrote: post #31

Interesting to compare with ETOPS (good maps: gc.kls2.com) which governs how far away from acceptable alternate airports a commercial plane can be. It corresponds to safe flying time with a single functional engine. So a lot of the area in some of the larger Voronoi regions, especially in the Southern Hemisphere, is actually unreachable by any commercial flight from the closest airport.

> is actually unreachable by any commercial flight from the closest airport. ETOPS is for twin engines (T for twin). Those restrictions do not apply to 3 and 4 engine aircrafts.

I thought it stood for "Engines turn or passengers swim"

I'm not sure I'd like to be on a plane 6 hours from an airport -- better hope you don't have any sudden medical requirements that would lead to a diversion!

Re: World Airports Voronoi (2014)

#93

Post by isostatic »

mikeash wrote: post #32
perilunar wrote: post #17

Earlier quoted context omitted.

Absolutely. It's a map of closest airport for any location on earth. You could do different versions of this for different classes of plane (e.g. select a minimum runway length).

This has a big influence on which routes a plane can fly. You can’t be more than a certain distance from a usable airport at any time during the flight to mitigate the risk of engine failure resulting in an off-airport landing/crash. See: https://en.m.wikipedia.org/wiki/ETOPS

And diversion airports of course vary with things like weather

Re: World Airports Voronoi (2014)

#95

Post by jasondavies »

handelaar wrote: post #85
jasondavies wrote: post #75

Earlier quoted context omitted.

This is probably the most frequently asked question! The data is from here: http://ourairports.com/data/ I had to limit the number of airports displayed for performance reasons. I filtered the airport data so that only those airports with scheduled services and which are denoted "large" or "medium" are included (according to OurAirports), bringing the number down to 2,980.

Suppose that'll explain why there are at least three airports included in Ireland that have no scheduled services at all: the data's from nearly a decade ago

Interesting. The data is from 2014, which is when I created the visualisation. Perhaps I should auto-update it every so often!

Re: World Airports Voronoi (2014)

#96

Post by catbird »

joakleaf wrote: post #7

I wonder what happens if you "give weight" to each point relative to size of the airport (measured e.g. by number of take-offs/landings per year)?

Then you get a "weighted Voronoi diagram," haha.

If the weights are multiplicative, the edges between adjacent cells become circular arcs. It looks cool, but it's much more difficult to generate and analyze. For instance, the region belonging to a generating point is no longer guaranteed to be convex, and may even have holes or be in multiple disconnected pieces.

Weighted Voronoi diagrams show up sometimes in multi-agent systems where agents have different speeds, e.g. pursuit-evasion problems, or in facility placement (where to build a new store/warehouse, etc).

Re: World Airports Voronoi (2014)

#98

Post by scroot »

jasondavies wrote: post #75
lisper wrote: post #64

This diagram is oddly selective about which airports it includes. It has some class D airports (Modesto, Santa Maria) but not others (Palo Alto, El Monte, Fullerton). There is no pattern that I can discern other than eliminating airports that are too close to each other, which kind of defeats the purpose of this exercise.

This is probably the most frequently asked question! The data is from here: http://ourairports.com/data/ I had to limit the number of airports displayed for performance reasons. I filtered the airport data so that only those airports with scheduled services and which are denoted "large" or "medium" are included (according to OurAirports), bringing the number down to 2,980.

St Helena airport is open and technically operational. It's certainly one of the most remote airports on the planet (this happened post 2015)

Re: World Airports Voronoi (2014)

#99

Post by [deleted] »

tzahola wrote: post #66
pvg wrote: post #40

Earlier quoted context omitted.

I know the former bit. I don't see how the latter obviously follows. You're basically saying it's related because it looks the same but it's clear from the picture it looks the same.

crystal seed = peanut butter nozzle crystal growth = peanut butter flow Imagine that the peanut butter is not poured from the top, rather coming from holes at the bottom of the cup. Initially there's a radially growing patch of peanut butter around each hole. When the peanut butter patches grow large enough, they touch, and form an approximately straight boundary (if the flow rate is equal for all outlets) like the b…

[deleted]

Re: World Airports Voronoi (2014)

#100

Post by MetallicCloud »

NKosmatos wrote: post #23

Nice one, actually all Voronoi diagrams are cool. If only there was a webpage/software where someone could click/select points on a map (or even better enter coordinates) and a user Voronoi diagram would be created ;-)

This does the job nicely http://alexbeutel.com/webgl/voronoi.html
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