Airport Layout Offset From Actual Aircraft Movement

[Rob Killins 897126]

I hope someone can help me resolve an issue with a newly rewritten sector file.

The airport layout - buildings, aprons, taxiways, runways etc. where all redrawn based on actual co-ordinates compiled from Google Earth. Co-ordinates where gathered from several specific points from Google Earth and written into the sector file resulting in an accurately detailed display of the airport layout in Euroscope.

 

However, we are faced with an annoying problem. Although aircraft transiting the runways are not as obvious, aircraft transiting the aprons and several (not all) taxiways are offset to what would equate to a few metres off the actual trajectory. So, an aircraft traveling down a taxiway may show up on the scope traveling off of it.

 

This image shows aircraft traveling north on taxiway H

 

This image shows aircraft traveling north on taxiway H after completing the turn in the taxiway (not leaving the ramp space)

 

This image shows aircraft at intersection of F-W

 

Has anyone experienced this in their own sectorfile development? Has anyone any suggestions on what factor(s) have contributed to this offset. Keep in mind, the runways appear not to suffer this same problem in the most part. Any suggestions as to how this can be repaired?

[Ernesto Alvarez 818262]

one factor is that you forgot to check the coordinates vs where FS has everything

 

first check default scenery, then check addon scenery.

 

Tampa has a similar problem because Flytampa's TPA scenery is offset from any other default/addon scenery.

 

sure gets fun during events you have people taxiing on a taxiway and someone coming in to land on that taxiway which on their scenery is where the runway is thankfully theres 2 sides to the airport so i usually sent the flytampa users to one side and everyone else to the other

[Luca Benelli]

Get the afcads for the most used scenery in the airport you want to work on and use them as a base..

Move everything else accordingly

 

Luca

[Rob Killins 897126]

Thanks folks for the replies ... me thinks this may not be an easy endeavour. I'm under the impression that the FS aircraft are using data which may not quite be real life, and I need to adapt my co-ordinates to match MSFS?

 

Ernesto, considering you had a similar problem with Tampa, other than manipulating the aircraft using the airport, did you resolve the issue? And how?

 

Luca, I guess the first question is ... what is an AFCAD, and where do I find them for the airports I'm needing to fix? Using the AFCAD data, is it fair to [Mod - Happy Thoughts]ume that my other airport layout co-ordinates can be easily converted to match the AFCAD format from that point, so in essence, it's the AFCAD data being changed?

 

Rob

[Ernesto Alvarez 818262]

yep, our sector file guru simply used the coordinates from the flytampa scenery and added that as a separate overlay that can be turned on and off from VRC so we can quickly bring up the flytampa version when needed.

 

its far from resolved tho as flytampa is not going to update the scenery to fix it since its a legacy product.

 

so its still ongoing

[Luca Benelli]

The afcad file is usually a definition of the airport (more or less complicated). You can extract them from FS BGL files or use some made for AI traffic (you'll find LOTS on avsim).

 

I don't think there's an easy way to correct your SCT files, except possibly if it's only a linear movemet with some text manipulation tools (perl anybody? i do all this stuff in PHP because it's the language i know better even if it's not the best choice).

 

Best choice is to start from the beginning with the correct data... you can only learn from mistakes...

 

Here's how we did our GND sector files in Italy.

 

All this come because I once saw an SCT Which looked as if it was created from some sort of blueprints of the airport...

 

http://www.metacraft.com/VRC/forums/viewtopic.php?t=1613

 

I then contacted Alexander Fath who made those SCT files, with his precious help i got the procedure to work in a more or less compicated way.

 

Take the AFCAD (it's FS stuff so it's exact with where the pilots will be moving), convert it into SCT format (i use a java script to make this).

 

Convert the SCT into CAD format (VBasic scripts from Alexander).

 

convert the PDF files of the airport layout into CAD format

 

Overlay the CAD files to match the afcad (which has the coordinates info).

 

convert the CAD file into SCT format removing the afcad "layer".

 

So you need a couple of persons good at crunching numebrs and somebody who has a copy and is a bit good at CAD... hard work but the results aren't bad at all.

 

http://www.ellebi.org/luca/foto/FS/varie/limc_vec02.jpg

 

Hope this helps..

 

Luca

[Miguel Frias]

We had some of this as well. There are a few different sceneries for our airport. The one that is most used is from Aerosoft and it is the most accurate one to reality.

 

So, using GoogleEarth and my tool it was possible to convert the accurate Google Earth layout onto Euroscope. This way, pilots don't taxi over the gr[Mod - Happy Thoughts].

 

Of course if they're using other/default sceneries then tough luck.

 

Miguel

[Rob Killins 897126]

Hi Miguel,

 

You're application looks very promising and may provide a reasonable solution to our problem. I set out to re-plot our airport on Google Earth in a preliminary effort to see the results of using your application. Unfortunately, I did not get the results I had hoped. Actually, I didn't get any results. The .sct file that resulted from an upload came back empty ... 0kb.

 

I feel I read your tutorial thoroughly, with only a few misunderstandings around colour, but it's unlikely that was the cause of the failure. Your post didn't suggest support, but are you able to provide some [Mod - Happy Thoughts]istance or suggestion as to how to get results?

 

Rob

[Miguel Frias]

But of course, I'll send you a PM with my email address. You can send me your KML/KMZ file so that I have a look of what's going on.

 

Miguel

[Jacques Malan 995061]

Hi Rob,

 

Are you sure that the conversion from google earth Decimal degrees to Degrees, Minutes, Seconds for the sector files are accurate?

 

I've been building sector files directly from google earth, and in 99% of cases I found that it is almost perfectly accurate. Only on some very small airports it may be offset by a couple of meters.

 

Just a thought...

[Miguel Frias]

Hello Jacques, was that for me?

 

I think the conversions are as accurate as I can get them to be. But if you have any specific example I can run a test and check it.

 

Miguel

[Rob Killins 897126]

Hi Jacques,

 

I use degrees.mins.secs by default on Google Earth, not the decimal variant. In the most part, the airport is accurately depicted ... the runways are fine, however, the taxiways and aprons, especially vertically running ones are off the equivalent of 100+/- metres in real life.

Just enough of an annoyance to sometimes question a pilot's safe transit through the airport.

[Ervins Reinverts]

Just as a heads-up, there is small nice program called af2sct, can be got here:

http://www.avsimrus.com/f/for-flight-controllers-20/af2sct-22738.html

It takes the BGL file and makes an sct out of it. Depending on the BGL, you may want to edit it in AFCAD program first to remove some elements that are not needed in the sct (for example, in our scenery we have some roads and car parkings defined there and these obviously are not needed in sector file.

When editing it, make sure you save it under different name and not overwrite the original BGL.

Have been using it for our airports and it works great.

[Martin Loxbo]

Here is another good tool for making airport layouts: http://fs.mine.nu/euroscope/design/

[Andrew Wolcott 814793]

...Take the AFCAD (it's FS stuff so it's exact with where the pilots will be moving), convert it into SCT format (i use a java script to make this).

 

Convert the SCT into CAD format (VBasic scripts from Alexander)...

 

Hope this helps..

 

Luca

 

Luca,

 

Could you please point me in the direction of where these VBasic scripts are, and any help with how to use them would be appreciated.

 

Converting SCT to CAD would make my life so much easier at the moment with Sector File Editing.

 

On another note, anyone know if there is a way to go from SCT or SCT2 into KMZ/KML? If I can't convert SCT or SCT2 into CAD, or DXF, then I'd like to import into Google Earth and go from there. Of course the easiest would be SCT/SCT2 converted to DGN or DXF, because then I could use MicroStation to do my drawings.

 

Thanks!

 

Andrew

[Miguel Frias]

Hi Andrew,

 

I don't know of such a tool (SCT->KMZ). It would have to be programmed which is not that easy. KMZ to SCT means stripping down a lot of info that the SCT file doesn't need. The other way round means reconstructing a lot of that information.

 

If you really want to give it a try then start from a new, fresh layout on GoogleEarth. While you may think it may be hard, it's actually not that hard and you'll get easily addicted to it, therefore it will be quicker

 

Miguel

[Luca Benelli]

Could you please point me in the direction of where these VBasic scripts are, and any help with how to use them would be appreciated.

 

Here's the basics... in the second page Alexander explained how to do it...

 

I'm trying to find his scripts again, the links he published in that thread are long dead

 

 

EDIT: missing link...

[Andrew Wolcott 814793]

Hi Andrew,

 

I don't know of such a tool (SCT->KMZ). It would have to be programmed which is not that easy. KMZ to SCT means stripping down a lot of info that the SCT file doesn't need. The other way round means reconstructing a lot of that information.

 

If you really want to give it a try then start from a new, fresh layout on GoogleEarth. While you may think it may be hard, it's actually not that hard and you'll get easily addicted to it, therefore it will be quicker

 

Miguel

 

Miguel,

 

Thanks for the reply. I am already quite familiar with tracing in Google Earth. This is why I want to import out Radar Video Maps and Trace the outlines of the airspace in the Tracons. This will helping during training and allow controllers to pull up a diagram that quickly shows the airspace layout for the position, such as Departure, or Terminal Arrival, or Final.

 

Here is a shot of our ASDE-X (ground radar) airport layouts at KATL and KCLT. These originally started out in Google Earth. We have since been able to obtain the real world ASDE-X CAD files, which are then converted over to SCT2.

 

 

Here is an example of an airspace outline for Atlanta Departure. This was done by taking a screen shot, doing some Geo-Referencing and tracing in GlobalMapper, then exporting to DXF, adding the altitude stratums in 3DSMax, and then exporting to SCT2. As you can see, Geo-Referencing is not that accurate.

 

Andrew

[Andrew Wolcott 814793]

Could you please point me in the direction of where these VBasic scripts are, and any help with how to use them would be appreciated.

 

Here's the basics... in the second page Alexander explained how to do it...

 

I'm trying to find his scripts again, the links he published in that thread are long dead

 

 

EDIT: missing link...

 

Thank you Luca.

 

If you find the scripts please let me know. I think I may email Alex to see if he still has these available.

 

Andrew

[Luca Benelli]

I wrote him today asking if it was ok for him to have the files published here...

I have them on my PC, just want to check that i send the right versions, the files Alexander sent me were in various steps of development and you had to choose the better suited file each time..

 

Luca

[Andrew Wolcott 814793]

I wrote him today asking if it was ok for him to have the files published here...

I have them on my PC, just want to check that i send the right versions, the files Alexander sent me were in various steps of development and you had to choose the better suited file each time..

 

Luca

 

Luca,

 

That sounds great! I will hold off on my email, and I eagerly look forward to his, and your response.

 

Thank you kindly for your efforts! I'm sure we can both agree too that Alex's efforts are much appreciated as well.

 

Andrew

[Ross Carlson]

Here is an example of an airspace outline for Atlanta Departure. This was done by taking a screen shot, doing some Geo-Referencing and tracing in GlobalMapper, then exporting to DXF, adding the altitude stratums in 3DSMax, and then exporting to SCT2. As you can see, Geo-Referencing is not that accurate.

 

Andrew, as part of a non-VATSIM project, I've done a small amount of work with parsing real world TRACON video map files into other formats. I might be able to [Mod - Happy Thoughts]ist if the video map files you have are in the format I've worked with previously. It sounds like you have the technical skills and probably already have this covered, but I thought I'd offer just in case.

[Luca Benelli]

http://flightsim.ellebi.org/varie/sector_files.zip

 

You'll find 4 files:

 

rohling.dxf - a basic DXF cad 2007 format file used by the BAS scripts

dxf2sct.bas and sct2dxf.bas - self explaining aren't they? check the code for the filenames to be used.

Main.java - this is a java file i made to read the xml output of bgl decompiler i used to get a sct trace of the runway and taxi centerlines out of an afcad files... you need something to center the cad drawings onto. I ran it using netbeans... hope it works.. it was an exercise because i couldn't get the BAS file to work...

 

Together with the instructions in the other thread you should get it to work.. if you need more help let me know.

It's not a fast or easy task but the results are without doubt above anything you've seen before.

 

I'd love to know about any improvement or automation in these files

 

Luca

[Andrew Wolcott 814793]

http://flightsim.ellebi.org/varie/sector_files.zip

 

You'll find 4 files:

 

rohling.dxf - a basic DXF cad 2007 format file used by the BAS scripts

dxf2sct.bas and sct2dxf.bas - self explaining aren't they? check the code for the filenames to be used.

Main.java - this is a java file i made to read the xml output of bgl decompiler i used to get a sct trace of the runway and taxi centerlines out of an afcad files... you need something to center the cad drawings onto. I ran it using netbeans... hope it works.. it was an exercise because i couldn't get the BAS file to work...

 

Together with the instructions in the other thread you should get it to work.. if you need more help let me know.

It's not a fast or easy task but the results are without doubt above anything you've seen before.

 

I'd love to know about any improvement or automation in these files

 

Luca

 

Thank you Luca!

[Alexander Fath 952810]

Gents,

 

if you like, I made some updates: http://www.metacraft.com/VRC/forums/viewtopic.php?p=13007#13007

 

 

 

Regards

Alexander Fath

 

Chief NAV Department

vACC Germany | RG Frankfurt

http://www.vatsim-germany.org | [email protected]