744 Forum

Apron => Hangar 7 => Topic started by: tango4 on Tue, 23 Dec 2014 14:39

Title: Feature Request: TDZ Lights
Post by: tango4 on Tue, 23 Dec 2014 14:39
Hi Hardy,
I have found that it is sometimes a bit hard to judge the proper aimpoint, even with the help of PAPI, especially on short final when handflying the plane.
I just feel that if I could see the touchdown zone (TDZ) lights materialized it would help. I guess the 744 being a big aircraft, it only flies to airport equipped with TDZ lighting so that would make sense.
The idea would be to add a double line of lights in the TDZ part of the runway.

I don't think this would be too heavy on the CPU, but I have ABSOLUTELY NO IDEA if it is hard to code, so please forgive me if this is too complicated and forget it completelyif that's the case.

The more I use this sim, the more I love it. You really did a terrific job !

Cheers.

Charles
Title: Feature Request: TDZ Lights
Post by: Hardy Heinlin on Tue, 23 Dec 2014 16:13
Hi Charles,

I'm sorry. I can't fulfill your wish.

Sorry!


Regards,

|-|ardy
Title: Feature Request: TDZ Lights
Post by: tango4 on Tue, 23 Dec 2014 18:11
No worries !
Thank for your fast answer as usual.
Title: Feature Request: TDZ Lights
Post by: Stephane LI on Wed, 24 Dec 2014 03:25
By the way, I am curious to know why in PSX, the PAPI lights are only equipped with 2 lamps (one red and one white when on the correct slope) instead of 4 lamps (2 red 2 white). Is it a programming limitation ?
4 lamps would be more precise to correct our slope, as it indicates slightly above, or well above the slope, or slightly below, or well below the slope.

Stephane
Title: Feature Request: TDZ Lights
Post by: Hardy Heinlin on Wed, 24 Dec 2014 10:29
It's because the PSX scenery is very much simplified. I keep this design style consistent for two reasons: 1. to make it clear that it is a simplification; 2. aesthetics (inconsistency looks ugly). The PAPI position is actually unknown; it can never be precise anyway. Lighting data is not in the nav database. PSX has to "autogenerate" it.


|-|ardy
Title: Feature Request: TDZ Lights
Post by: tango4 on Wed, 24 Dec 2014 15:12
Just to clarify things, my request was about a simplified generic TDZ.
Just something like the first xxx meters of every runway (xxx to be decided as a global PSX value) with a double row of lights instead of a simple.
The idea is to quickly get a feeling that you are making a long landing. Nothing involving a database.

Good night everyone and happy holidays !
Title: Feature Request: TDZ Lights
Post by: John H Watson on Thu, 25 Dec 2014 02:44
Do all (reasonably long) runways have fixed distances between markers?

According to wiki, there are different types of markers, but no mention of different distances.

http://en.wikipedia.org/wiki/Runway
Title: Feature Request: TDZ Lights
Post by: Balt on Thu, 25 Dec 2014 09:25
According to ICAO aerodrome standards doc section 5.3.9.6, for an instrument runway, the runway edge lights are not to exceed 60m, and for a non instrument rwy, they are not to exceed 100m. See here http://www.icao.int/safety/implementation/Library/Manual%20Aerodrome%20Stds.pdf

This nicely accommodates the metric world where 50m is common, and the U.S. where 200ft is common.

Cheers

Balt
Title: Feature Request: TDZ Lights
Post by: tango4 on Thu, 25 Dec 2014 09:42
Well, even if it is not 100% standard in the world, I guess it is not an issue.
You only need to decide a convention for a standard TDZ and apply it everywhere (as long as it is documented).
The idea I had in mind was just to get a small visual help for manual landing.
Anyway, don't worry if it is too much trouble Hardy, it's just Christmas wishes !

Merry Christmas to everyone here !

Charles
Title: Feature Request: TDZ Lights
Post by: cagarini on Sat, 27 Dec 2014 08:59
Also, the PAPIs in PSX are more a kind of APAPIs than PAPI since I can only see two lights.
Title: Re: Feature Request: TDZ Lights
Post by: Tom Gorzenski on Fri, 31 Dec 2021 16:06
Agree. PAPI instead of APAPI would definitely be much more appreciated, since PAPI is required for all runways with precision approach, and all instrument runways with reference code 3 and 4. Also, PAPI is essential for approaches with large airplanes, and particularly - jet airplanes.
Title: Re: Feature Request: TDZ Lights
Post by: cavaricooper on Sat, 1 Jan 2022 15:51
Quite a while ago, Hardy had indicated some possibility of adding runway specific approach lighting sometime, much farther down the road.  I remain hopeful for that as well.  That, with the PAPIs and TDZ lighting would go a long way towards eliminating the need for scenery generators. As much as I love the eye candy, nothing transmits inertia and momentum feel as well as PSX solo does. 

Perhaps once his "list" gets shorter, there will be time. Hope springs eternal... Happy 2022!

Best- C
Title: Re: Feature Request: TDZ Lights
Post by: Tom Gorzenski on Sun, 2 Jan 2022 16:18
Absolutely. I will keep my fingers crossed.
All the best, Happy 2022.
Title: Re: Feature Request: TDZ Lights
Post by: Timo on Sun, 2 Jan 2022 21:07
...but keep in mind that many airports (e.g. KJFK) use VASIs instead of PAPIs.

happy new year,
Timo
Title: Re: Feature Request: TDZ Lights
Post by: United744 on Sun, 2 Jan 2022 21:44
PAPIs are aligned with the ILS glideslope, broadly speaking (I mean physically on the ground). You know where the glideslope is, so you know where to put the lights.

Maybe just update the lighting so if the runway has an associated ILS it changes the lighting? From what I can tell you already have the required information to make it work.
Title: Re: Feature Request: TDZ Lights
Post by: Hardy Heinlin on Mon, 3 Jan 2022 01:52
The scenery loader just scans the runway database, not the ILS database which has the G/S position. So it would require an additional database scan and matching algorithm solely for the purpose of adding two further cosmetic dots in an already extremely simplified "dot scenery". -- I want to keep the style of the simplification consistent. As soon as one object looks 100% realistic, all other objects will look like errors. Like a photo-realistic ear on a picasso-esque face abstration. I doubt anyway that your landings will improve just because you see 4 instead of 2 dots.
Title: Re: Feature Request: TDZ Lights
Post by: Jeroen Hoppenbrouwers on Mon, 3 Jan 2022 12:28
In this world, technical arguments always kill it.

A side question. If PSX would magically gain knowledge of the runway's actual configuration in great detail, down to the last approach light -- what would the impact be on the painting routine? Say, full ALSF-2 added to a runway, and then for six runways (6 directions) on the same airport?


Hoppie
Title: Re: Feature Request: TDZ Lights
Post by: Hardy Heinlin on Mon, 3 Jan 2022 12:49
Depends on the computer ...
Title: Re: Feature Request: TDZ Lights
Post by: Jeroen Hoppenbrouwers on Mon, 3 Jan 2022 16:41
I'll ask it differently. The _current_ painting routine. Does it, for example, calculate and store the exact position (lat/lon/alt) of each blip as soon as the airport gets close enough, and from then on "just" paint the whole large array of lights from coordinates in memory? Or are there code shortcuts, such as a line of blips being reduced to begin and end point, and the code interpolating, to save on memory at the expense of lines of code?

If it is flat from-memory painting, then a future extension could possibly load up the airport blip map from a file and then users could load up their machine to whatever they tolerate.

It would of course need special blips for the rabbit and the VASI/PAPI.

Hoppie
Title: Re: Feature Request: TDZ Lights
Post by: Hardy Heinlin on Mon, 3 Jan 2022 18:07
There are no dotted lines. Each spot is actually a filled square with individual, distance related size and transparency.
Title: Re: Feature Request: TDZ Lights
Post by: Jeroen Hoppenbrouwers on Mon, 3 Jan 2022 20:54
The positions of these squares, are they calculated every frame by an algorithm that knows how to paint a pattern given a runway begin/end point, or is this pattern calculated once as the runway gets nearly in sight and then stupidly dropped in a table for stupid, but fast repainting every frame?

The distance-dependent size and alpha of course remains a heavy burden for each frame.

I think this is going to be a dead end. But if not, it opens up a slew of creative possibilities  :-)
Title: Re: Feature Request: TDZ Lights
Post by: Hardy Heinlin on Tue, 4 Jan 2022 04:10
When a nearby runway is loaded from the nav database, PSX generates dot objects (squares) for that runway; every dot object gets planet related, static lat/lon/alt values (in the program, not on the screen). These will be continuously retransformed to 2D-windshield projection coordinates in every time frame, referring to the current flightdeck lat/lon/alt, heading and attitude. The transformation happens in PSX, not in the graphics card -- in case that's what you are thinking about.

So there are 3 actions:

1. Generate 3D dot position data for the planet (whenever the aircraft has travelled some miles)
2. Calculate 2D monitor projection objects (in every time frame)
3. Send the projection objects to the 2D graphics card

(Note that "2D" in this context means what it is: 2D. All our eyes look at 2D screens, even within Virtual Reality helmets. We are not on Star Trek Holodecks yet.)

|-|
Title: Re: Feature Request: TDZ Lights
Post by: Jeroen Hoppenbrouwers on Tue, 4 Jan 2022 11:04
Ok, this is what I thought you had done. It means that theoretically it could be possible to extend the system with one more step and then theoretically have freedom to paint whatever until the CPU blows up.

Step 1 could get a step 1b:

1b. Look up which Special Dot Files are within range and if within range, load the individual dots specified in that file, by lat/lon/alt/colour, into the same table as the 3D planet dots.

I have absolutely no idea what impact this would have on steps 2 and 3. Maybe you could for fun add a large flat plane of dots, like 5 km by 5 km with a dot every 10 meters, that would be 250 000 dots, and see what that does to the frame rate.

It won't solve the PAPI challenge but for static approach lighting it may offer a DIY option.


Hoppie
Title: Re: Feature Request: TDZ Lights
Post by: G-CIVA on Tue, 4 Jan 2022 13:23
Or we could give HH a break & home build another PC as a scenery generator & run the academic version of something like p3Dv4/5 integrate it with PSX on its own PC  :D

Only joking 🙃 
Title: Re: Feature Request: TDZ Lights
Post by: Tom Gorzenski on Tue, 4 Jan 2022 19:53
Quote from: Hardy Heinlin on Mon,  3 Jan 2022 01:52
The scenery loader just scans the runway database, not the ILS database which has the G/S position. So it would require an additional database scan and matching algorithm solely for the purpose of adding two further cosmetic dots in an already extremely simplified "dot scenery". -- I want to keep the style of the simplification consistent. As soon as one object looks 100% realistic, all other objects will look like errors. Like a photo-realistic ear on a picasso-esque face abstration. I doubt anyway that your landings will improve just because you see 4 instead of 2 dots.

I believe it would - just like in real life, where PAPI allows for a more precise descent along the glide path, as it allows for gradual signaling of deviations from the glide path. Moreover Hardy, please note, it is not unusual, especially on short final, to observe that PAPI indications differ from the ILS glideslope indications - for some runways they do not coincide precisely (they are supposed to coincide to the maximum possible extent, but due to variety of reasons, they not always do). So there is nothing to worry about. Why not tie the generic 3.00 deg PAPI more or less rigidly to the distance (1000 feet) from the runway threshold? So, the runway database would be sufficient to scan. Basically we would get 4 lights instead of 2, that's all what is proposed.
However I am not familiar with software challenges to meet this goal - please excuse my ignorance.
Title: Re: Feature Request: TDZ Lights
Post by: Hardy Heinlin on Wed, 5 Jan 2022 04:52
Quote from: Tom Gorzenski on Tue,  4 Jan 2022 19:53
Why not tie the generic 3.00 deg PAPI more or less rigidly to the distance (1000 feet) from the runway threshold?

This is already implemented. Most real life systems refer to a threshold overflight at 50 ft AGL at 3°, and that's also the standard in the PSX visual "PAPI" simplification.

As I explained above, I want to keep the style of the simplification consistent in the entire windshield. None of the runway light rows are complete (edge lights, center lights, stop lights etc.). Either all or nothing.
Title: Re: Feature Request: TDZ Lights
Post by: evaamo on Wed, 5 Jan 2022 08:54
Quote from: Jeroen Hoppenbrouwers on Tue,  4 Jan 2022 11:04
1b. Look up which Special Dot Files are within range and if within range, load the individual dots specified in that file, by lat/lon/alt/colour, into the same table as the 3D planet dots.

I have absolutely no idea what impact this would have on steps 2 and 3. Maybe you could for fun add a large flat plane of dots, like 5 km by 5 km with a dot every 10 meters, that would be 250 000 dots, and see what that does to the frame rate.

I remember writing back in 2018 something along the lines in this forum:

"- A modification in PSX that would allow reading from a (set of) file(s) a format comprised of a set of points (lat/lon coordinates, altitude, color, blinking or not...something of sorts) that could become part of the scenery and be displayed by PSX graphics engine natively. Then, it being an open format, we could develop a 2D editor for building taxiways, beacons, obstructions, even gates or parking stands not shown on the actual gates DB.  Maybe even read a BGL file (not too difficult) and generating the necessary taxiway lines in PSX format. "

<nudge nudge>  Hardy!!!

Have a great new year, guys!
-E
Title: Re: Feature Request: TDZ Lights
Post by: Hardy Heinlin on Wed, 5 Jan 2022 09:20
By the way, did you guys notice that the 2-lamp PAPI lights in PSX cannot only be white or red but also rosy?

So there are 5 levels:

white - white
rosy - white
red - white
red - rosy
red - red

But the rosy sector is very small. It's just to get a smooth transition between white and red. I could make that rosy sector larger according to the real PAPI sectors, so that the sectors are equally separated.
Title: Re: Feature Request: TDZ Lights
Post by: United744 on Wed, 5 Jan 2022 10:52
Quote from: Hardy Heinlin on Wed,  5 Jan 2022 09:20
By the way, did you guys notice that the 2-lamp PAPI lights in PSX cannot only be white or red but also rosy?

So there are 5 levels:

white - white
rosy - white
red - white
red - rosy
red - red

But the rosy sector is very small. It's just to get a smooth transition between white and red. I could make that rosy sector larger according to the real PAPI sectors, so that the sectors are equally separated.

Yes I had. I thought it was related to blending artifacts between red/white rather than a defined segment though.
Title: Re: Feature Request: TDZ Lights
Post by: Tom Gorzenski on Wed, 5 Jan 2022 11:35
Quote from: Hardy Heinlin on Wed,  5 Jan 2022 09:20
By the way, did you guys notice that the 2-lamp PAPI lights in PSX cannot only be white or red but also rosy?

So there are 5 levels:

white - white
rosy - white
red - white
red - rosy
red - red

But the rosy sector is very small. It's just to get a smooth transition between white and red. I could make that rosy sector larger according to the real PAPI sectors, so that the sectors are equally separated.

Interesting, good to be finally sure what that phenomena is, but there is no real life equivalent of such system. I mean, what we have now in PSX is actually APAPI system (modified with an additional rosy color as a substitute of more precise guidance delivered by 4 PAPI units).

I.a.w. ICAO Annex 14, APAPI can be used only for instrument runways with reference code digit of 3 and 4 (reference takeoff distance 1200-1799m for "3" and 1800m and more for "4") with non-precision approach only. If there is a precision approach, no matter what runway lenght, a more precise guidance systems than APAPI or straight VASI is required, like T-VASIS or AT-VASIS, with PAPI being preferred worldwide, however. This is why I don't feel happy with APAPI in PSX, even though now you have explained that it is a PSX-only modified APAPI in order to deliver more precise guidance than 2 units of a straight APAPI.

I understand that the only reason we don't have PAPI in PSX is your personal preference of such greatly simplified outside world representation, and this is not about any software issue, or increased computing power requirements. If we can't get PAPI, then yes - please make the rosy sectors larger to match PAPI's 3 reds/1 white and 1 red/3 whites sectors. Alternatively, please use amber instead of rosy.

BTW, you can make it even more simplified - why not to use PVASI or tricolor VASI? Advantage is, both of them are real life systems used at smaller U.S. airports. And computing power needed would be even lower.

PAPI and APAPI sectors (4 and 2 light units respectively):
https://www.easa.europa.eu/sites/default/files/online-publications/EasyAccessRulesforAerodromesRegulationEUNo1392014Revisionfro-75.png

AT-VASIS (10 light units):
https://www.dst.defence.gov.au/innovation/tee-visual-approach-slope-indicator-system-t-vasis
https://youtu.be/3LRF_fJLNq4

PVASI (Pulsating VASI) (single light unit)
https://www.faa.gov/air_traffic/publications/atpubs/aim_html/images/aim_img_98ac7.jpg

Tricolor VASI (single light unit)
https://www.faa.gov/air_traffic/publications/atpubs/aim_html/images/aim_img_eee93.jpeg
Title: Re: Feature Request: TDZ Lights
Post by: Hardy Heinlin on Wed, 5 Jan 2022 12:11
Quotemodified with an additional rosy color as a substitute of more precise guidance delivered by 4 PAPI units

No, it's not for more precision. It's just an anti-flicker intermediate step, only 0.0001° wide. The real thing must have a (tiny) transition zone as well as its size is greater than zero.


Well, OK, guys ... I'm in the mood for a little cosmetic work today. I'll try to add two more lamps for a 4-lamp PAPI today. But that's all. No TDZ etc.

And I'll remove that rosy transition as I guess it's of no use anyway.
Title: Re: Feature Request: TDZ Lights
Post by: United744 on Wed, 5 Jan 2022 12:17
Quote from: Hardy Heinlin on Wed,  5 Jan 2022 12:11
Quotemodified with an additional rosy color as a substitute of more precise guidance delivered by 4 PAPI units

No, it's not for more precision. It's just an anti-flicker intermediate step, only 0.0001° wide. The real thing must have a (tiny) transition zone as well as its size is greater than zero.


Well, OK, guys ... I'm in the mood for a little cosmetic work today. I'll try to add two more lamps for a 4-lamp PAPI today. But that's all. No TDZ etc.

And I'll remove that rosy transition as I guess it's of no use anyway.

Thank you!! :D :D
Title: Re: Feature Request: TDZ Lights
Post by: Jeroen Hoppenbrouwers on Wed, 5 Jan 2022 12:41
Quote from: Hardy Heinlin on Wed,  5 Jan 2022 12:11
No, it's not for more precision. It's just an anti-flicker intermediate step, only 0.0001° wide. The real thing must have a (tiny) transition zone as well as its size is greater than zero.
"not more than three arc minutes" I believe on the real thing.
Title: Re: Feature Request: TDZ Lights
Post by: simonijs on Wed, 5 Jan 2022 17:55
PAPI - or any other (simplified) visual approach guidance system - is not to be used for landing the aircraft, it is there to stay away from (obscured) obstacles in the approach path. Once the aircraft is within the obstacle free airport perimeters - and by the latest overhead the threshold - the pilot will start focussing on the runway aiming point itself. (S)He won't be looking that much at PAPI lights anymore.

If you look at the picture below, with a 747 exactly following the electronic glidepath, the pilot of this 747 will see a completely different "image" of the PAPI lights than the pilot of a C-172 or B-737 following the exact same electronic beam. If I recall correctly, PAPI's are set to show the correct 3 degrees "two white-two red" eye level path for the type of aircraft that most frequently lands at that particular airport.

(https://www.hoppie.nl/forum/var/2022-01-05_16.39.58_ILS_747.jpg) Source: KLM's (obsolete) AOM

Flaring the aircraft will change the perspective of what you see from the PAPI, i.e. if you keep focussing on those lights. Touchdown will occur with the cockpit already passed the PAPI lights. PAPI and TDZ lighting are two different topics. By the way...: some airports have a 3 degrees electronic glide slope, but a 3,2 degrees PAPI system (which is worth some attention in the approach briefing).

Another picture for a non-precision approach below; in this case KLM recommended to choose an aiming point some 600 meters from the runway threshold. No word in the manual on how to interpret PAPI lights, since the aircraft already is overhead the threshold.

(https://www.hoppie.nl/forum/var/2022-01-05_17.22.25_Non_precision_747.jpg) Same source

Regards,
Simon
Title: Re: Feature Request: TDZ Lights
Post by: Will on Wed, 5 Jan 2022 18:17
The scientist in me wants to get some pilots and a NASA-level simulator(*) and test this empirically. Let's look at 100 landings made using all possible visual cues, and then start removing the visual cues singly and in combination, until we determine what part(s) of the sight picture really contribute to good, safe landings.

(We could also poll the pilots to see what contributes most to a sense of "immersion" in the simulator environment, and it would not surprise me at all if "immersion" and "safety" are goals that are best met in different ways.)

*) Does NASA have good simulators?
Title: Re: Feature Request: TDZ Lights
Post by: Jeroen Hoppenbrouwers on Wed, 5 Jan 2022 18:31
Quote from: Will on Wed,  5 Jan 2022 18:17
*) Does NASA have good simulators?

At least one.
https://www.nasa.gov/mission_pages/shuttle/behindscenes/shuttletrainingaircraft.html
Title: Re: Feature Request: TDZ Lights
Post by: Tom Gorzenski on Wed, 5 Jan 2022 19:05
Quote from: Hardy Heinlin on Wed,  5 Jan 2022 12:11
Quotemodified with an additional rosy color as a substitute of more precise guidance delivered by 4 PAPI units

No, it's not for more precision. It's just an anti-flicker intermediate step, only 0.0001° wide. The real thing must have a (tiny) transition zone as well as its size is greater than zero.

Well, OK, guys ... I'm in the mood for a little cosmetic work today. I'll try to add two more lamps for a 4-lamp PAPI today. But that's all. No TDZ etc.

And I'll remove that rosy transition as I guess it's of no use anyway.

Thank you Hardy! Having PAPI instead of APAPI will make visual portions of those pesky NPAs, circling finals, and visual approaches easier and better stabilized by detecting vertical deviations faster that requires less elevator and power adjustments, since the PAPI's "on glidepath" (2 reds/2 whites) sector is 1/3 narrower than that of APAPI - 20' vs. 30'. Additionally, PAPI provides significant deviation warning, while APAPI does not.

And yes, of course - my mistake - I intended to write about the POTENTIAL use of those rosy (or better yet - amber) sectors, as equivalent of 3 reds/1 white and 1 red/3 whites sectors of PAPI by making them equally wide, 20 arc minutes to be exact.
Title: Re: Feature Request: TDZ Lights
Post by: Hardy Heinlin on Thu, 6 Jan 2022 18:58
Quote from: Hardy Heinlin on Wed,  5 Jan 2022 12:11
And I'll remove that rosy transition as I guess it's of no use anyway.

I've changed my mind; I'm keeping that rosy transition in the 4-lamp PAPI as well which I just implemented. With that smooth transition it looks more realistic, even if the rosy sector is just 3 arc minutes wide.
Title: Re: Feature Request: TDZ Lights
Post by: alcannata on Thu, 6 Jan 2022 20:41
I agree: excellent idea (IMHO)!
Thank you Hardy for each development of PSX.

Aldo
Title: Re: Feature Request: TDZ Lights
Post by: Tom Gorzenski on Thu, 6 Jan 2022 23:36
Quote from: Hardy Heinlin on Thu,  6 Jan 2022 18:58
Quote from: Hardy Heinlin on Wed,  5 Jan 2022 12:11
And I'll remove that rosy transition as I guess it's of no use anyway.

I've changed my mind; I'm keeping that rosy transition in the 4-lamp PAPI as well which I just implemented. With that smooth transition it looks more realistic, even if the rosy sector is just 3 arc minutes wide.

Perfectly fine with me. Many thanks Hardy.

P.S. that rosy thing reminds me of FedEx Flight 1478 crash. Despite putting all the blame on FO's deficient color vision and crew fatigue by the NTSB, not everybody got convinced - there was a certain issue with the PAPI lights involved in the crash, due to their design (or a malfunction) and high humidity which caused condensation of water on the PAPI front lens inner surfaces, resulting in significant PAPI color characteristics change - if I remember correctly. And there were two other crew members in the cockpit - nobody said a word, even though they got low enough for the PAPI to display 4 reds for quite a long time.
https://www.cvdpa.com/images/news/uploads/Pape_and_Crassini_2013_The_Puzzle.pdf
Title: Re: Feature Request: TDZ Lights
Post by: Hardy Heinlin on Fri, 7 Jan 2022 07:09
Actually, the rosy sector itself now has a gradual color change. There's no switch effect at all anymore, not even a switch to/from rosy :-) Even though the transit takes just 3 arc minutes (0.05°), it looks much more realistic this way, i.e. smoother rather than flipidee-floppidee.
Title: Re: Feature Request: TDZ Lights
Post by: Tom Gorzenski on Fri, 7 Jan 2022 10:34
Quote from: Hardy Heinlin on Fri,  7 Jan 2022 07:09
Actually, the rosy sector itself now has a gradual color change. There's no switch effect at all anymore, not even a switch to/from rosy :-) Even though the transit takes just 3 arc minutes (0.05°), it looks much more realistic this way, i.e. smoother rather than flipidee-floppidee.

Yes, it's true that a there is normally a color transition zone between red and white, in any PAPI/APAPI light unit. Please note that 3' is the absolute maximum allowed as per ICAO Annex 14, point 5.3.5.30. See also ICAO Doc 9157 points 8.3.8 and 8.3.9. The color transition to be considered satisfactory sharp, should appear virtually instantaneous when viewed from ranges in excess of 300 m. The transition zone can not be greater than 3'.

You wrote earlier that presently (10.149), the transition sector is only 0.0001°. I have found it to be more like 0.005° or 0,0001 rad - approx 2 ft from 3.0 NM, which is about 0.3 arc minute. So, this is approx. 10 x less than the maximum limit established by ICAO. Understand you are going to make it now 10 x wider, right at the maximum limit established by ICAO. Thats' fine but you might take into consideration that modern PAPI LED systems tend to have a bit better performance than 3'.
Title: Re: Feature Request: TDZ Lights
Post by: Hardy Heinlin on Fri, 7 Jan 2022 12:40
You mean I should reduce it to 2 minutes? :-)
Title: Re: Feature Request: TDZ Lights
Post by: Tom Gorzenski on Fri, 7 Jan 2022 13:25
Quote from: Hardy Heinlin on Fri,  7 Jan 2022 12:40
You mean I should reduce it to 2 minutes? :-)

Well, I can have more detailed information on that subject from some PAPI/APAPI manucturers next week (I have been involved recently in an aerodrome lighting project). But I have never heard in recent years that any PAPI or APAPI unit had failed to meet that requirement during certification tests or complete installation tests and flight test. So, I think they must do noticeably better than 3'.
I would be fine with 3' transition if you decide to make it so, but I would say 2' would be realistically just about right, most likely... :-)
Title: Re: Feature Request: TDZ Lights
Post by: Hardy Heinlin on Fri, 7 Jan 2022 13:36
Quote from: Tom Gorzenski on Fri,  7 Jan 2022 10:34
You wrote earlier that presently (10.149), the transition sector is only 0.0001°.

I was just kidding with an exaggeration, similar to the word "zillions". I don't recall the exact angle.
Title: Re: Feature Request: TDZ Lights
Post by: Tom Gorzenski on Fri, 7 Jan 2022 15:25
Quote from: Hardy Heinlin on Fri,  7 Jan 2022 13:36
Quote from: Tom Gorzenski on Fri,  7 Jan 2022 10:34
You wrote earlier that presently (10.149), the transition sector is only 0.0001°.

I was just kidding with an exaggeration, similar to the word "zillions". I don't recall the exact angle.

Understood :-)
P S. But you have been pretty close to the actual number, though... ;-)
Title: Re: Feature Request: TDZ Lights
Post by: Hardy Heinlin on Fri, 7 Jan 2022 21:37
The 4-light PAPI is now implemented in PSX 10.150: https://aerowinx.com/board/index.php?topic=4191.0


|-|ardy
Title: Re: Feature Request: TDZ Lights
Post by: Tom Gorzenski on Fri, 7 Jan 2022 21:40
Quote from: Hardy Heinlin on Fri,  7 Jan 2022 21:37
The 4-light PAPI is now implemented in PSX 10.150: https://aerowinx.com/board/index.php?topic=4191.0

|-|ardy

What?! I was supposed to go to bed... It will need to wait :-)
Thank you Hardy!

P.S. The PAPI works great! Good to have PAPI instead of APAPI...
Title: Re: Feature Request: TDZ Lights
Post by: Raj Hoonjan on Sat, 8 Jan 2022 17:26
Quote from: Hardy Heinlin on Fri,  7 Jan 2022 21:37
The 4-light PAPI is now implemented in PSX 10.150: https://aerowinx.com/board/index.php?topic=4191.0


|-|ardy

Currently, I use PSX in standalone mode only and this is a fantastic enhancement.

Thank you Hardy.
Title: Re: Feature Request: TDZ Lights
Post by: Mariano on Sat, 8 Jan 2022 18:04
THANK YOU!

Mariano
Title: Re: Feature Request: TDZ Lights
Post by: Frans Spruit on Sun, 9 Jan 2022 12:24
Hi Hardy,

.150 is top!
Thank you very much,

Frans Spruit
Title: Re: Feature Request: TDZ Lights
Post by: Tom Gorzenski on Sun, 9 Jan 2022 15:43
Quote from: Hardy Heinlin on Fri,  7 Jan 2022 21:37
The 4-light PAPI is now implemented in PSX 10.150: https://aerowinx.com/board/index.php?topic=4191.0

Good day Hardy.

Could you please verify that the new PAPI angular sectors are exactly as depicted here:
https://www.easa.europa.eu/sites/default/files/online-publications/EasyAccessRulesforAerodromesRegulationEUNo1392014Revisionfro-75.png
?

I did some measurements of those sectors in the PSX today and found out, that while the "on glide path" (2 whites/2 reds) sector's width was pretty close to the expected 20 arc minutes, both the slightly low (1 white/3 reds) and slightly above (3 whites, 1 red) sector widths were approx 6 arc minutes each - only a bit more than a half of the normal width per ICAO standards - 10 arc minutes.

What I got for one particular runway (EHAM Rwy 06):
well below glide slope <2°45'
slightly below glide slope 2°45'-2°50'
on glide slope  2°50'-3°10'
slightly above glideslope 3°10'-3°15'
well above glidelope >3°15'

i.a.w. ICAO Annex 14:
well below glide slope <2°30'
slightly below glide slope 2°30'-2°50'
on glide slope  2°50'-3°10'
slightly above glideslope 3°10'-3°30'
well above glidelope >3°30'

Alternative ICAO sector widths for the purpose of better harmonisation of ILS glide path and PAPI signals to a point closer to the threshold:
well below glide slope <2°25'
slightly below glide slope 2°25'-2°45'
on glide slope  2°45'-3°15'
slightly above glideslope 3°15'-3°35'
well above glidelope >3°35'

Personally I would prefer the standard sector widths in PSX, because of the narrower "on glide slope" sector width - only 20 arc minutes, instead of 30 arc minutes (same as for APAPI, previously featured in PSX).

Again, many, many thanks for introducing PAPI to PSX :-)

Kind regards,
Tom
Title: Re: Feature Request: TDZ Lights
Post by: Hardy Heinlin on Sun, 9 Jan 2022 15:52
Can't verify your numbers.

For the sector separation, PSX uses these angles:

3.5000°
3.1666°
2.8333°
2.5000°


Regards,

|-|ardy
Title: Re: Feature Request: TDZ Lights
Post by: Dirk Schepmann on Sun, 9 Jan 2022 16:35
Thank you very much for the continuous improvement of PSX!
Title: Re: Feature Request: TDZ Lights
Post by: Tom Gorzenski on Sun, 9 Jan 2022 17:07
Quote from: Hardy Heinlin on Sun,  9 Jan 2022 15:52
Can't verify your numbers.

For the sector separation, PSX uses these angles:

3.5000°
3.1666°
2.8333°
2.5000°


Regards,

|-|ardy

Thank you Hardy!

To get my numbers I used "Basic 024 - Landing" situation, had the aircraft positioned of final approach at 1.5 NM KAG DME, motion off, and then was moving the aircraft vertically, observing all four PAPI lights to go from white to red. I noted the altitudes I got (from the Instructor/Situation/Position), which were used to calculate the angles. The altitudes noted were OK, but it looks like I must have made a calculation error, because after recalculation I got the new numbers very close to yours.

Just by flying in the sim everything felt right but the numbers did not match earlier, that's why I asked. I am sorry. The width of transition from white to red seemed to be approx. 5 feet, or 1.9' (max allowed by ICAO = 3'), just like mentioned earlier. Thank you!
Title: Re: Feature Request: TDZ Lights
Post by: Hardy Heinlin on Sun, 9 Jan 2022 20:22
No problem :-)
Title: Re: Feature Request: TDZ Lights
Post by: Tom Gorzenski on Tue, 11 Jan 2022 11:18
Quote from: Tom Gorzenski on Tue, 11 Jan 2022 11:18
Quote from: Tom Gorzenski on Fri,  7 Jan 2022 13:25
Quote from: Hardy Heinlin on Fri,  7 Jan 2022 12:40
You mean I should reduce it to 2 minutes? :-)

Well, I can have more detailed information on that subject from some PAPI/APAPI manucturers next week (I have been involved recently in an aerodrome lighting project). But I have never heard in recent years that any PAPI or APAPI unit had failed to meet that requirement during certification tests or complete installation tests and flight test. So, I think they must do noticeably better than 3'.
I would be fine with 3' transition if you decide to make it so, but I would say 2' would be realistically just about right, most likely... :-)

Hardy, reference is made to my above comment...

I have received a LED PAPI unit test report prepared by an authorized photometric laboratory. Unfortunately I am not allowed to reproduce it here, or mention the name of the PAPI manufacture, however, I can quote the following excerpt from the report:

"C. Determination of transition zone:

Conditions: the transition zone must not be greater than 3 minutes of arc in depth, at azimuth angles up to 8 degrees either side of the center of the beam, expanding to no greater than 5 minutes 15 degrees either side of the center of the beam.

Measured transition zone at 25 meters:
  - in the optical center of the beams product, the transition zone has a width of 18 mm and by calculation it was obtained an angle of 0.04° or 2.4 minutes < 3 minutes, 
  - at 8° on either side of the center of the beam by calculation it was obtained an agle of 0.048° or 2.89 minutes < 3 minutes."

This is a wider transition zone than I expected...