RogerBW's Blog

I've been renewing my interest in the Flightgear flight simulator. And it turns out there's a neat trick you can do with it.

Real-world aviation charts are expensive, as are most things that are required by regulation and have only a monopoly provider. To the flight simmer, though, there's another problem: the charts may not exactly match the scenery built into the simulator.

So what one really wants for flight planning is a system to which one can add one's own data (for airports, navigational aids, etc.), and then plot directions and distances: if I want to be at this point, what's the distance and bearing to that VOR-DME transmitter?

(In case it needs to be said: all this is not for real-world aviation.)

Fortunately there's a system that can do that: the same Viking software that I already use for planning walks and providing maps during on-line RPGs. But can we take this a step further? Specifically, Flightgear has an extensive system of diagnostics which make the aircraft's current position available, and Viking can plot the output of a GPS receiver…

What's needed is an adaptor. So I wrote one. Using AnyEvent for asynchronous operation, it interrogates Flightgear's httpd for position information, converts the numbers, and allows connections to an imitation gpsd; Viking then connects to that fake server and plots positions.

And it works!

Of course, you might not find much use for this:

when Flightgear already gives you this:

but Viking can do more: I can add to it the navaids that are in the scenery rather than in the current real-world data, I can rule off distances and bearings, and I can save that track and export it as a GPX file.

Once I've tidied this up a bit I'll release the code.