Board index FlightGear Development Scenery

Incorrect Airport Data

Questions and discussion about enhancing and populating the FlightGear world.

Incorrect Airport Data

Postby pmorenogarcia » Mon May 17, 2021 5:21 pm

Hi everyone

I would like to report an error that I have detected in the airport database. In FlightGear, if you look for LEJR airport (Jerez Airport, Cádiz, Spain) you found an airport with four runways: 03-21 and 02-20. But actually LEJR is a small airport and 03-21 runways do not exist (probably is an old denomination). You can check at https://aip.enaire.es/AIP/#LEJR or Google Maps https://www.google.es/maps/@36.744829,- ... a=!3m1!1e3

I know that in my local copy I can delete one line from Airports/apt.dat.gz/apt.dat and 03-21 runways do not appear. But, how can I make this change affect everyone who wants to use FlightGear?

Thanks in advance.

Best Regards
pmorenogarcia
 
Posts: 4
Joined: Mon May 17, 2021 4:28 pm

Re: Incorrect Airport Data

Postby wkitty42 » Mon May 17, 2021 6:25 pm

pmorenogarcia wrote in Mon May 17, 2021 5:21 pm:But, how can I make this change affect everyone who wants to use FlightGear?

simply put, you cannot... the best you might be able to do would be to generate custom scenery and provide the needed NavData fixes with it...

the real and proper fix will come when FG is able to update the data it has and rebuilds the world scenery it uses... until then, we can only use what we have, really... even if it is slightly old and out of date...
"You get more air close to the ground," said Angalo. "I read that in a book. You get lots of air low down, and not much when you go up."
"Why not?" said Gurder.
"Dunno. It's frightened of heights, I guess."
User avatar
wkitty42
 
Posts: 9148
Joined: Fri Feb 20, 2015 4:46 pm
Location: central NC, USA
Callsign: wk42
Version: git next
OS: Kubuntu 20.04

Re: Incorrect Airport Data

Postby pmorenogarcia » Mon May 17, 2021 6:52 pm

Thank you very much, wkitty42

I am new here and I don't now how FlightGear community works, but in this case it is not necessary to rebuild the scenery, only delete one line of a file. If someone with the proper permissions change the file in the server, the new version of FlightGear will be correct as far as real runways in LEJR are concerned, am I right?

By the way this file is in Airports folder, not Scenery.

Of course, something need to be done with the scenery (now you can find 03 and 21 instead of 02 and 20 in the runway) but I understand this is not so easy as delete a line.

Indeed, I work at University of Cádiz and we are involved in a teaching project that use FlightGear and maybe we can change this scenary as part of the project (LEJR is our reference airport). But first I have to learn how the FlightGear community works and how easy is to make these changes.
pmorenogarcia
 
Posts: 4
Joined: Mon May 17, 2021 4:28 pm

Re: Incorrect Airport Data

Postby AzulProfundo » Mon May 17, 2021 10:39 pm

Hi pmorenogarcia,

It is not sufficient to update the apt.dat to correct the situation. That file is used like a "source code" to generate the airport part of the scenery, using a tool from the TerraGear suite. It is also used as a guide for the FGAirports tool, which creates the groundnet for the AI Traffic component. The FGAirports part is the one I know more about, and it is easier to do. For a custom scenery, you have to use TerraGear and combine the Elevation Mesh, vector data (usually from OSM) and the apt.dat, in order to generate the scenery files FlightGear requires.

For the apt.dat, the World Editor WED from X-Plane is used. But many elements in it have to be purged out in order to TerraGear can process the file.

The custom scenery thus generated can be shared apart from the TerraSync server, for those wanting to download it, and later (eventually) be merged into the main TerraSync scenery, when releasing a new version of FlightGear.

The components which are being maintained regularly and have an implemented update procedure are the groundnets (through groundweb, accessed from the FGAirports app) and the 3D Objects, through the https://scenery.flightgear.org/ page.

I could help with the groundnet, but with the TerraGear I am just starting and getting some help from more experienced users.
My current project is to create the groundnets for the Azores. And yes, an update to the scenery is also required there, although in most cases it is not required for groundnets.
__________________________________________________________________________
Slimbook ES (Ubuntu Notebook)
AzulProfundo
 
Posts: 97
Joined: Sat May 09, 2020 12:54 am
Location: Portugal
Version: 2020.3.8
OS: Ubuntu 20.04

Re: Incorrect Airport Data

Postby ludomotico » Tue May 18, 2021 10:53 pm

pmorenogarcia wrote in Mon May 17, 2021 6:52 pm:Indeed, I work at University of Cádiz and we are involved in a teaching project that use FlightGear and maybe we can change this scenary as part of the project (LEJR is our reference airport). But first I have to learn how the FlightGear community works and how easy is to make these changes.


Hi pmorenogarcia,

As you say, 03-21 runway is probably the old denomination of the current 02-20 runway. For some unknown reason, when a runway changes its denomination, sometimes, somehow, the runway is duplicated in apt.dat

Duplicated runways happen at least at two airports in Spain: LEJR-Jerez (already reported: viewtopic.php?f=5&t=39046 ), LEPP-Pamplona (also reported: viewtopic.php?f=5&t=38884 ) I'm sure this also happens to other airports in the world: a similar issue was reported a couple of days ago at Santiago de Cuba. The fix is not only removing the line in apt.dat, the scenery must be rebuilt to prevent the duplicated runway to be drawn on the scenery as well. Indeed, if you look closely, there are two runways at LERJ one on top of the other!

There are things that are easy to change in the FlightGear community, others not so much. Changing the apt.dat file, even a single line, is one the the hardest things because so many other parts of the project and other projects depend on this file. The community seems to work like "the apt.dat file changes only once in a decade"

Of course, this affects only to the "official" FlightGear distribution. You or your university can distribute a custom scenery for LEJR. In fact, WoodSTokk provides a complete fix for LEJR: viewtopic.php?f=5&t=39046#p384875 . As you can see, it involves much more than a single line. There was a time when I provided a custom scenery for the whole Iberian Peninsula, because so many airports suffered from issues similar to this one: https://wiki.flightgear.org/Custom_Spai ... al_scenery

There are other things that you can definitely do and submit to the community: improve the buildings at LEJR, for example. Creating buildings does not imply changing the layout of the scenery, and seeing your buildings accepted in the database is a much faster process (days!)
User avatar
ludomotico
 
Posts: 1269
Joined: Tue Apr 24, 2012 2:01 pm
Version: nightly
OS: Windows 10

Re: Incorrect Airport Data

Postby pmorenogarcia » Thu Jun 10, 2021 7:53 am

Thank you very much, AzulProfundo and ludomotico.

I am calmer now knowing that this error is already reported.

Respect the WoodSTokk fix, I forgot to say that we are using v 1.0 of the scenery, but after some investigation about hex-files, I think I found a similar solution. It is reported in the original post.
pmorenogarcia
 
Posts: 4
Joined: Mon May 17, 2021 4:28 pm


Return to Scenery

Who is online

Users browsing this forum: No registered users and 10 guests