Where are they flying to?

Experiments in flight tracking using golang

Transcript

1. Where Are They Flying To? @andrewl
 http://www.andrewl.net Geomob London
 2nd November, 2016
 BCS London
2. I’m going to talk about airports. More specifically the locations of airports.
3. I live to the west of London, near to Heathrow Airport…
4. …but fortunately not under either of the main flightpaths. The east-west prevailing winds mean that the other people get more problems from flights. We do have the occasional aircraft flying overhead though.
5. Sometimes they’re high enough to leave vapour trails…
6. …but often they look like this
7. ? The question that I wanted to ask was where are they flying to?
8. I don’t know what i’m talking about. I’m not an expert on this, and this is only a hobby project. Some of what follows might be incorrect or hearsay, but broadly it’s correct. So, how do we find out which airport an aeroplane is bound for?
9. Turns out it’s not like this.
10. Often it’s like this - secondary radar. The dish spins which activates a transponder on the aircraft which in turn sends information back.
11. ✈ ✈ ✈ More frequently these days it’s using ADS-B “automatic dependent surveillance-broadcast”. Aircraft constantly broadcast information such as speed, position, altitude - this can be picked up by ground stations, other aircraft, potentially even satellites. More like a distributed system.
12. This is how flightradar24 works - users receive these broadcasts then feed back into flightradar24 who use the aggregated data to produce realtime maps. I wanted to build up a database of flights over my house to find out where they were going to.
13. ✈ position velocity identifier 1090MHz Aircraft constantly broadcast packets of data on 1090MHz Position, velocity, identifiers and other information.
14. ✈ position velocity identifier 1090MHz You can pick these messages up using a $15 USB DVB/FM stick. The supplied aerial can pick up aircraft in a ~10 miles radius. Alternatively you can build your own aerial using a wire coat hanger and pick up aircraft hundreds of miles away.
15. ✈ position velocity identifier 1090MHz dump1090 These messages can be decoded using the dump1090 software https://github.com/MalcolmRobb/dump1090 which can in turn stream out the decoded messages over tcp network connection.
16. ✈ position velocity identifier 1090MHz dump1090 collector wherearetheyflyingto I wrote ‘wherearetheyflyingto’ in go - a high performance language from google. I knew it would have no problem with the amount of data being received.
 Internally it’s built from a number of components. The ‘collector’ assembles information about a flight from the various messages it transmits. It stores this in a lightweight, expirable, in-memory cache.
17. ✈ position velocity identifier 1090MHz dump1090 collector overhead? wherearetheyflyingto The ‘overhead’ component determines whether a flight has passed overhead. Overhead is quite an imprecise term though and what constitutes ‘overhead’ is actually determined in part by the altitude of the aircraft.
18. ✈ position velocity identifier 1090MHz dump1090 collector destination
 finder Website Website Website overhead? wherearetheyflyingto The Destination Finder component takes a flight number and retrieves the destination latitude-longitude by means of screen scraping various websites. The website sources are independent and pluggable (ie you can choose at runtime which sources to use) and take advantage of go’s interfaces.
19. ✈ position velocity identifier 1090MHz dump1090 collector destination
 finder Website Website Website overhead? wherearetheyflyingto Logs logger Once a complete set of data for an aircraft flying overhead - altitude, position and destination - has been collected the logger component writes an entry to a log file. This is aggregated in a centralised logging system which then pushes a notification to a slack channel…
20. ✈ position velocity identifier 1090MHz dump1090 collector destination
 finder Website Website Website overhead? output wherearetheyflyingto DB Logs logger …the output component then also writes a record to a db. Periodically this database is queried and produces new data for a heat map - this is published using github’s publishing framework, github-pages at https://andrewl.github.io/wherearetheyflyingto
21. Heatmap indicates that most flights are destined along an arc from central Europe, the Middle East and Indonesia, with another hotspot in North America.
22. The altitude filter provides a more nuanced view.
 Flights under 9000 feet are often destined for Frankfurt, Munich, Geneva, Athens, Istanbul
23. …and a few locations further afield, notably Dubai.
24. At the other end of the altitude scale, flights over 27000 feet - usually seen leaving vapour trails are destined for locations nearer to home - including Paris, Netherlands, Bristol, Birmingham, Newcastle and Dublin
25. In the middle of the altitude range - around 9000-18000 feet - there’s a huge hotspot around London. What’s going on?
26. It appears that although I’m not under a flight path from Heathrow it appears that I am under major flightpaths for both Luton and Stanstead airports!
27. Image Credits https://www.flickr.com/photos/hodgers/14004031 https://www.flickr.com/photos/14730981 OpenStreetMap contributors https://www.flickr.com/photos/policyexchange/9031727127 https://www.flickr.com/photos/redroseexile/4030294714 https://www.flickr.com/photos/conifer/26692785722 http://forgottenflix.com/wp-content/uploads/2012/07/Elaine-and-Ted-with-the-automatic-pilot-Otto..jpg https://www.flickr.com/photos/osde-info/9548550771
28. Thank you https://andrewl.github.io/wherearetheyflyingto https://github.com/andrewl/wherearetheyflyingto @andrewl
 http://www.andrewl.net