Positioning of Runways

[J D ADAM]

Hi Hardy
              How are you handling the position of runways in PSX?
I am aware of the difference between FS2004 and  PS1, which was overcome with Visual PS1.
I did not drag you away from your important work, so a quick answer is all I need!

Regards
Derek

[Hardy Heinlin]

Hi Derek,

quick answer: It will be handled by certain delta values.

:-)

|-|ardy

[Holger Wende]

Hi Hardy,

Dereks question for runway positions raised annother question:
Does PSX model runway slope, too?

Regards, Holger

[torrence]

Not sure, Holger, but may be difficult.  This is not definitive - I don't know exactly what Hardy is including -  but I think you would require local digital elevation models with less than meter accuracies vertical and maybe a few meters horizontal to model typical 0.1 deg type slopes on long runways.  There are terrain grids at that resolution for some areas, but putting thousands of such grids laid on top of a global model at airport locations might be a lot of work.  I remember some hi-res scenery for FS that might have mesh resolution at this level, but I don't think they ever modeled anything but flat runways for dynamics.  Anyone ever checked?

Cheers,
Torrence

Edit

The above represents just my geographical thinking.  I suppose you might be able to include slope in the PSX flight model for the ground with a increased rolling friction term or something similar when going uphill.  Maybe that's what you meant anyway.

T

[Holger Wende]

Hi Torrence,

Would you really need a local detailled elevation model just to model two (or more) elevation points of a runway? Good point! Initially I only thought about the runway itself. But it becomes difficult unless we do not want to e.g. "fall down" to a lower taxiway when vacating the runway. But this might be a solvable issue.
MSFS never modelled the runway slope in contrast to X-Plane, as far as I know.

Of course I do not want to request any complicated earth model. I was just thinking about some influence on take-off and stop distance and of course the visual effect during approach.

The visual effect of a rising/falling runway might fool a pilot to think he is too high/too low on approach. But I have no idea whether this effect is noticable on the PC screen. Hmmm, I guess I need to calculate a bit...

By the way: HAPPY EASTER TO EVERYBODY out there  

Regards, Holger

[Jeroen Hoppenbrouwers]

As far as I can see there are two aspects of sloped runways that do not need to be implemented together.

One is abstract: the extra drag or thrust that a sloped runway generates during takeoff or landing roll. This kind of data is available from charts and relatively easy to implement.

One is concrete: the vertical profile of the runway. Unlike the charted slope, this may be a weird kind of shape, convex, concave, with a bump, etc. There are runways that are curved in such a way that when you are near touch down, you completely lose sight of the far end and it pops into vision again when you are over the crest. Or runways that have a dip which means you flare waaaaay too long if you don't push down firmly.

With the concrete, actual profile needing a 1 or 10 meter elevation resolution, or else manual tuning, and also a very tight link between world model and visual model, this probably needs to be approximated. There is no point in PSX modelling a dip or bump while the visual system projects a mathematically straight runway.


Jeroen

[Hardy Heinlin]

Good morning,

quick answer: Plan A: Use runway threshold elevations from the database and runway crossings to compute an airport terrain profile, override this as usual when external scenery elevation is injected. Plan B: Make a flat average. -- No matter which plan or injection: Use runway gradient from database to compute performance.

Cheers,

|-|ardy


Quick P.S.: To avoid stairway effects at runway crossings, it's actually not necessary to first compute those crossing elevations. I'll try a mixing algorithm that takes every runway threshold in the vicinity into account by using the sum of all lateral distances from these thresholds to the aircraft -- and the percentage of each distance relative to the sum, translating that percentage to an interpolated non-straight elevation profile, instead of using just two elevations and a straight line in between.

[Hardy Heinlin]

By the way, PSX contains 6708 airports. All these airports have one or more runways longer than 1400 meters:




|-|

[Holger Wende]

Hi,

That airport overview reminds me of an inverted version of NASAs night earth city lights -> Images & Animations. What s surprise

Regards, Holger

[Hardy Heinlin]

(Click to enlarge)






|-|

[Jeroen Hoppenbrouwers]

Very nice.

Wonderful how much suggestion comes from the geo data.

Does your database also contain the full name of the airports? This could open possibilities (later) to show stuff in a tool tip popup when a user hovers the mouse pointer over an airport code.

Or, right-click an airport label, and a menu offers interesting options such as "add to weather page as tab".

Later  

[Hardy Heinlin]

Full names also, yes. I'm going to make an airport info page under the Analysis section, similar to that in PS1.

|-|

[Jeroen Hoppenbrouwers]

Will these PSX database files be in unencrypted binary (i.e., easily editable with a program), plain text (editable with anything), or encrypted/obfuscated?

[Hardy Heinlin]

They have to be encrypted as they are not free.

...

By the way, does anybody know where to find (purchase?) a list of ICAO country codes and their full names? E.g.

EN = Norway
ES = Sweden
K1 = Alaska
K2 = Utah
etc.

I have searched the ICAO site but found no hint ...

I guess I'll have to write it manually.

|-|

[Pierre Theillere]

Hi all!

In case it's useful for someone else too:
http://www.airlinecodes.co.uk/icaonat.asp
Enjoy!

[Holger Wende]

or this (German only):
http://de.wikipedia.org/wiki/ICAO-Code

English version with a nice map overview:
http://en.wikipedia.org/wiki/ICAO_airport_code

Holger

[Hardy Heinlin]

That's it!

Thank you, Pierre!

|-|



Edit: Heck, I thought I had checked Wikipedia as well. Thank you, Holger.

(But note that I'm usually interested in the sources mentioned in Wikipedia, not Wikipedia itself, that's too risky.)

[Hardy Heinlin]

Hard to tell which source is correct:

http://www.airlinecodes.co.uk/icaonat.asp

http://en.wikipedia.org/wiki/ICAO_airport_code

E.g. Armenia varies ...

[Pierre Theillere]

Hi Hardy and folks!

Erevan airport (in Armenia) seems to be UGEE according to http://www.skyscanner.fr/aeroports/evn/erevan-aeroport.html maybe it can help a little bit!

[Hardy Heinlin]

I have a UDYZ UD N40085019 E044234517 YEREVAN INTL in the database.