As in previous question I am trying to transpose a geospatial data format from within a EUROCONTROL application into something I understand, like decimal lat-lon.

An answer to my previous question Reference Map of EUROCONTROL charging zones got me a long way forward. I now understand that the data references this map: enter image description here

This is the result of plotting the data in the file directly onto the screen. In the case of EG (UK airspace) I've added little circles to show the coordinates.

Result of plotting data into SVG

What I now need to do is to take some of the points within my file and have the actual coordinates in lat-lon (or indeed any commonly used format).

It seems to me that the boundaries of the map might be set by waypoints (or perhaps vice versa). I grabbed this image from aeroresource.co.uk and annotated it to illustrate my theory.

My assumption

It looks to me like the boundary of north east boundary of EG matches with the line of waypoints indicated by the annotated green line. So the north boundary starts with RATSU to the east and GUNPA to the west.

The easternmost boundary runs from RATSU to the north to NIBOG to the south.

enter image description here

And finally, to my questions

Is that assumption correct? Is the boundary of the various airspace zones delimited by waypoints?

If yes - is there an authoritative source of that information?

If no - is there an authoritative source of whatever points are being used to draw the bounds of the airspace?

  • $\begingroup$ If your question is "Is european airspace delimited by markers RATSU, GUNPA, and NIBOG", the title should reflect it. See the help center for more information $\endgroup$
    – Manu H
    Mar 30, 2020 at 8:28
  • $\begingroup$ Rather than update the title, I've updated the question. $\endgroup$
    – AviPrice
    Mar 30, 2020 at 8:54
  • $\begingroup$ You should consider how charges are calculated in areas with delegated airspace. For example, Denmark controls a bit of German and Scottish airspace. I don't know if flights through those areas pay to Denmark or to the other countries. Those boundries do not match the map you have. $\endgroup$ Mar 30, 2020 at 10:41
  • $\begingroup$ The boundaries as I drew them are lifted directly from the EUROCONTROL application designed for the specific task of calculating nav charges, so I'm confident I've got the correct data for my requirements. $\endgroup$
    – AviPrice
    Mar 30, 2020 at 10:46
  • $\begingroup$ @BenMayo you should also update the title as this is a Q&A website and more importantly it helps navigate through questions without opening each question. $\endgroup$
    – Manu H
    Mar 31, 2020 at 9:08

2 Answers 2


No, your assumption is not correct. Airspace boundaries are not defined by waypoints, but by WGS84 lat/lon pairs, which you can probably just use directly without a lot of manual work.

You need to consult the national Aeronautical Information Publication (AIP) for the country in question to get the coordinates for their national airspace, called a Flight Information Region (FIR). Specifically, look in AIP section ENR 2.1 (all AIPs worldwide are structed in the same way). Here is an example for the UK: https://www.aurora.nats.co.uk/htmlAIP/Publications/2020-03-26-AIRAC/html/eAIP/EG-ENR-2.1-en-GB.html#ENR-2.1

I recall having downloaded a global file with FIR coordinates for the entire world somewhere off the web, although I don't remember exactly where. It may well have been published by the ICAO. You might be able to locate it if you look around a bit.

  • $\begingroup$ However, many of those lat/lon pairs may end up as waypoints for convenience of handoffs between ATSUs, and because routing policies and services may be different on each side. $\endgroup$
    – StephenS
    Mar 30, 2020 at 14:40
  • $\begingroup$ Sure, a lot of waypoints are located along the borders of FIRs. Not so commonly in the corners though, and that's what OP needs $\endgroup$ Mar 30, 2020 at 14:46
  • $\begingroup$ Success - I took the London FIR points, converted them to decimal lat-lon and plotted them on a map. The numbers being used within the application are 60 x the decimal lat-lon. Which makes sense. $\endgroup$
    – AviPrice
    Apr 3, 2020 at 11:34

The boundaries of the European airspace are not defined by waypoints. There are however many waypoints on the boundaries. This is mainly for practical purposes related to air traffic control. These waypoints are used as clearance limits and transfer points for coordination between adjacent Flight Information Regions.

I think the additional points you found on the east-west boundary in the north have a different purpose. The boundary is along a circle of latitude. Normally, when you would just use the two endpoints of that line segment, you would create a great circle which is not along the circle of latitude. By inserting addional boundary points, the deviation between the great circle line segments and the circle of latitude (a specific case of a rhumb line) is limited.

enter image description here souce


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