744 Forum

Good morning,

is there any add-on developer on the forum who is -- within the next 20 months -- seriously interested in making a simulation of a system that sends route waypoint winds and OATs to PSX's FMS?

Background:

Like PS1, PSX's FMS has the RTE DATA page. Unlike PS1, PSX now models FANS functions as well, i.e. data communication between aircraft and dispatcher (and ATC). With FANS, the RTE DATA page has got a key to request and load route wind data sent by a virtual dispatch office.

PSX has a dynamic planetary weather model based on latitudes and the current season. There's not much info available to the PSX pilot about the variable winds and temps along the cruise in the upper airspace. There's only a jet stream chart -- and METARs for the lower airspace at airports. This reduction of information is intentional. Now the pilot can request the missing route winds and temps from the virtual dispatch office. This virtual dispatch office, included in PSX, knows PSX's dynamic planetary weather model, and so it can calculate the data for each route waypoint.

When the weather data in the FMS agree with the data of the physical weather model, VNAV can make better fuel and ETA predictions.


Back to the foreground:

So much for PSX's internal features. An external add-on, on the other hand, may create a route weather scenario of its own, e.g. using current real life cruise weather. This might be injected into PSX for two purposes:

1. Feed PSX's FMS with requested wind/OAT data
2. Feed PSX's planetary weather model

This would require a special file format as it should be separated from the FMS variables (do not overwrite them directly because they are managed internally by the ACT/MOD/EXEC/ERASE logic etc.). This is work that I will do only if there's serious interest within the next 20 months. Otherwise, we may discuss this again later, for a later update of PSX.


Cheers,

|-|ardy

P.S.:

The maximum data amount the FMS can take is this:

120 waypoints per route
4 altitude references per route
4 wind directions and speeds per waypoint (1 at each altitude reference)
1 OAT altitude reference per waypoint
1 OAT per waypoint (at OAT altitude reference)

The FMS uses a special algorithm to extrapolate that single OAT entry to the other altitudes. The FMS also fills empty wind data fields.

The minimum data amount the FMS needs is this:

1 altitude with wind direction and speed at one waypoint (the last waypoint would be the best one).

Hardy, are you also simulating the precise roasting time of the coffee beans used to brew the coffee in 1st class? And the exact vinegar content of the salad dressing used on the lettuce in coach? I'm amazed.

Yes, I am.

Regrettably, you won't be able get it out of your computer.

My current knowledge is that the readily available enroute weather data is graphical in nature. You print a map full or small arrows and then guesstimate your way through it.

If somebody has a reliable source of enroute data, it gets interesting to work on this.

In the past I implemented a warping probe in SB747 to feel the VATSIM weather ahead. I literally warped the ownship position one radar sweep to the waypoint ahead to get the wind and temperature reading, because this was (and is?) the only way of getting VATSIM local conditions at altitude. By then, they used a simple algorithm for this but it wasn't disclosed as far as I know, so you had to go there to feel the wind.

I understand that most people fly online using real weather from different sources than VATSIM, using dedicated weather injectors that get data from "somewhere". Are there people here who know more about the sources?

Delivery of data to the aircraft is, of course, no problem at all. Heck I do that for a living.


Jeroen

Hi Hardy and Hoppie!

Maybe you could get in touch with Christian Gril (developer of TOPCAT, and pending PFPX), as it's been over a year since the flightplanning tool has been enabled to get worldwide real-world enroute (altitude) wind data.

Jeroen Hoppenbrouwers wrote

If somebody has a reliable source of enroute data, it gets interesting to work on this.

Jeroen

SimWX ?

Little off topic ...
For now I use HiFi's Activesky with FSBuild to get accurate wind projection for planned route - approximate winds and temps (AcitveSky then feeds Fsbuild with wind info). SimWx does also that but I can't get wind info feed back into Fsbuild to get accurate fuel predictions. That's the process ...

best regards,

vito

The route via TOPCAT seems the best one to start with, especially since TOPCAT already interfaces with ACARS.

I've pointed Christian at this thread.


Jeroen

PFPX looks to be at least as good as any existing professional flight planning software thanks to Doug Snow and Chris Grill.

I believe that PFPX, incorporating TOPCAT, will plan for en route winds but, of course, only at the time of the planning. At actual flight en route, the wx and fuel usage may be different. So it would be great if the actual winds encountered could be used against the original FP wx, as in real world. And wx reports to a virtual ATC would be useful.

The future looks bright!

See http://forum.avsim.net/topic/379750-high-level-winds/

Just re-visited the PFPX site and remembered that the FPs produced will contain all the forecast winds aloft. PFPX provides a sample at http://www.pfpx.com/Sample.pdf

Can PFPX also generate a plain ASCII text of the wind data, i.e. a file that can be easily parsed by a machine?

The best solution would be if the wind data were stored in each WPT line in the ASCII text flight plan that PFPX already generates.


Cheers,

|-|ardy

I presume that there should come an extension of the TOPCAT/PFPX system aimed at producing machine-readable data beyond the FMC route, including the ACARS uplink capability. All infrastructure is there. "Just" the glue is needed.


Jeroen

Hardy,
I do not think that PFPX can produce a weather file in text at preset, only a FP in text. Chris Grill (support[at]topcatsim.com) is the man to ask for what you are after.
Cheers, R

mcdonar wrote

http://www.pfpx.com/Sample.pdf

Page 9 in this PDF has exactly what is needed: The required values and an ASCII text format. The only problem is that the text block is embedded in a PDF.

I post on Christian's forum every now and then. But he's very busy, apparently.


Cheers,

|-|ardy

Great! But you presumably will require a separate text file rather then extracting data from a .pdf?

Suggest that you ask Chris for exactly what you require. I know he is very busy at times, but if you require the data, he will likely be happy to provide it in your format, even though it may take some time to get it. I am sure that it would be worth the wait.

Hardy Heinlin wrote

mcdonar wrote

http://www.pfpx.com/Sample.pdf

Page 9 in this PDF has exactly what is needed: The required values and an ASCII text format. The only problem is that the text block is embedded in a PDF.

I post on Christian's forum every now and then. But he's very busy, apparently.


Cheers,

|-|ardy

I'm not sure that I am following the details of your needs, but the current release of Adobe Acrobat has a built-in OCR feature, allowing one to extract text from a PDF file. There are also software packages that can easily convert a PDF into an Excel spreadsheet, a MS Word file, etc. I suspect that you actually need a plain text file, not some ad hoc thing coming from Adobe Acrobat...

Hello all,

PFPX could indeed provide the data required like wind speed, wind direction and temperature at different times (STD-12 hours to STD+36 hours) and all levels up to FL700.

These data are extracted from NOAA and extremely accurate compared to other sources. In fact, the information is provded as GRIB file (Gridded binary) and converted by PFPX on the local system of the user.

At this time, there is no option to retrieve a text file with required information directly from the server.

In order to use these data in PSX, the user would also required PFPX to be running and doing the conversion. Formatting the data to a certain layout can be done pretty easily, however.

Hi Chris,

This means that we have a data path. Now it is just seeing who is going to walk it. We have about a year, so I think it will be done in time to meet PSX.


Jeroen

Hi Christian,

welcome to the forum!

Quote

In order to use these data in PSX, the user would also required PFPX to be running and doing the conversion. Formatting the data to a certain layout can be done pretty easily, however.

So we "just" need to discuss the certain layout? :-)

If I may, I would suggest to use just four steady reference altitudes through the whole route, as the FMC can't take more than four anyway.

As suggested by Bulfer's FMC Guide, I would set these four reference altitudes like this:

(1) 4000 feet above cruise altitude
(2) At cruise altitude
(3) 4000 feet below cruise altitude
(4) 25000 feet MSL


My plan on the PSX side: PSX shall be able to ...

... load PFPX route files into PSX's FMC (already discussed on your forum)
... load PFPX wind/OAT data files into PSX's weather model and FMC

Of course, the current wind/OAT data file in use must agree with the current route file in use. Both files must contain the same waypoints and their correct sequence.


Cheers,

|-|ardy

ACARS can deliver files from a source to a specific folder on disk or offer the files on a socket or as Qs. No problems there. The FMS has to validate the files and can reject them.


Jeroen

It would be nice if the data delivery would appear like a -- I don't know how to call it -- like a "setup event", "Instructor event", just a data delivery, not like an avionics simulation.

There's a data hub on the Instructor ("Dispatcher" tab). The data should first arrive there (folder on disk).

From there, PSX can send the wind and OAT to ...

(A) ... PSX's physical planet weather simulation
(B) ... PSX's avionics simulation

There should be no direct contact between (A) and (B). They are two isolated worlds. Mother Nature doesn't enter numbers in the FMC, and the FMC doesn't change Mother Nature.

In other words, there should be a one-way street from the data hub to PSX's FMC model, and another one-way street from the data hub to PSX's weather model.

On the Dispatcher tab I want to implement some menus and checkboxes, e.g.:

Select stored forecast report:
| VHHHWSSS-21-08-2012
| DONALDDUCK-20-08-2012
| ...

Received forecast report:
[x] Enabled for ACARS uplink to aircraft FMC
[x] Controls upper airspace weather simulation


Cheers,

|-|ardy

Hi H!
I gather from the first paragraph of your entry above implies that you wish to go with a weather forecast (i.e. get the data from a source such as PFPX) and not from a real-time source (i.e. such as HiFiTechnologies at http://www.hifitechinc.com/).
Cheers, R

Hi Richard,

yes, I'd like to get the data from PFPX. PSX should be able to import outputs from PFPX.

But any external add-on (independent of my planned PFPX import function) can inject weather data into PSX -- anytime. That's beyond my scope, that's up to the add-on developers.


Cheers,

|-|ardy

Data hub is a brilliant idea. Best diagnostic tool ever.

Dropping a file there can indeed automagically offer it to the FMS, no matter what file it is (route, winds, performance, ...).


Jeroen