Weather injection into PSX...

[cagarini]

I wonder if it would be possible / desirable, to have a sophisticated weather generator for FSX / P3D like ASN injecting it's weather into PSX instead the way around.

I am aware that PSX uses a very sophisticated weather model, including jetstream effects, etc..., but ASN and FSX / P3D users using those sims as visual generators for PSX might be interested in this possibility.

There would have to be a good description of the variables / classes used for weather generation in PSX, and I don't know if the crew at HiFiTech would even be interested in such an extension for their product, but I might ask at their beta forum...

[JP59]

I have the same request

[Peter Lang]

Yes this would be a nice feature.

I used FSGRW which provided very good weather for FS9. It is also designed for FSX and P3D and provides weather over the oceans.

Peter

[cagarini]

Yes, FSGRW is yet another very good weather injcetor for FSX / P3D.

ASN goes a bit further in the way it models winds, temps, and in the near future even non isa pressure gradients ( geopotential height ) for the first time in fsx / p3d.

The problem may well lay in setting a sound and as complete  as possible b translation between the weather variables used in both sims.

[JP59]

The most penalizing problem I see is about winds aloft data. PFPX predictions are totally wrong, because PFPX and PSX do not use the same source for winds aloft. PSX has it's own planet weather, and PFPX has real world or weather add-on data. I can understand that predictions and real weather can be a little bit different, but when you see a difference of 30Kts of headwind component, it makes a huge fuel consumption difference at the arrival !

I made several long haul flights using PFPX and PSX, there is a huge difference between the winds I see within PSX ND and what I read in the PFPX flight plan (as I said before, sometimes up to 30Kts of headwind or tailwind component). The result is 15 to 20 minutes flight time differences at the arrival, and the consequence is that PFPX fuel predictions are not accurate. I have to take 10 tons of extra fuel for every long haul flights to avoid low fuel issues. This is not very realistic.

There is many many weather engines, and I think it will never be possible to satisfy everybody.

I think there is 2 solutions :

1- PSX downloads real world winds aloft data, and inject these data within PSX world. Thus, when building the PFPX flight plan using real world weather data, PFPX and PSX data will match.

2- PSX takes PFPX winds aloft data and inject these data within PSX world. Thus, PFPX and PSX data will match regardless where PFPX data comes from (real world, Active Sky, REX, etc...)

The 2nd solution is the best. It will need PSX to have access to PFPX weather file, interpret it and inject within PSX world. A thick box inside Situation/Weather could be added to allow PSX to inject PFPX winds aloft data.

Let's talk about the weather visuals (clouds, visibility, precipitations). Of course, it will be the perfection to have, for example, a CB within PSX WXR display and see it out of the window, using Active Sky Next or other WXR stuffs for FSX. It would need PSX to take the data directly from these add-ons and inject within PSX world. Maybe it is going a little bit too far, I don't know what is possible or not. I remember a flight at EGLL, the PSX METAR reported rain, but AS2012 reported no rain. Result : no rain in visuals within FSX, but I listened the rain on the windshield because PSX had rain. Both PSX and AS2012 use real world METARs from the internet, but they do not download data at the same time. It causes unrealistic situations. If PSX weather engine could be fed directly from these add-ons it would avoid these situations.

It is very easy to say "It will need", "It should be"... Hardy made a HUGE work already and released the most accurate flight simulator I've ever seen, by far. But I know also he is a perfectionist and I hope he will have a look on that for future updates.

[cagarini]

Excellent post JP744...

The more I think about it, the more I believe that I really want to keep PSX's World weather model, at most with downloaded METAR by enabling the METAR Downloads and "Set zones by flight track and downloaded METARs" option in the "Weather" Tab.

I was thinking about buying PFPX, but it is expensive, I would not use it for other civil sim, and there are freeware options available that suite my needs...

And, last but certainly not least, HH did a remarkable job with it's World Weather model, including jetstream paTterns, modeling of geopotential height, etc... My colleagues at the metoffice really liked my demo!

[JRBarrett]

A third option would be if there were a way for PSX to export a current snapshot of its upper-atmosphere wind/temperature model in a format that PFPX could read and utilize for its calculations. Even though such a snapshot would not correspond to actual real-world upper winds on a given date and time, it should lead to very accurate fuel burn predictions in PFPX for a particular flight.

Such a "snapshot" is already partially available by requesting an upper winds download in the FMS after a route has been entered and activated. The predicted winds/temps can be seen for each waypoint on the RTE DATA pages. I know of no way (at present) to manually enter that info into PFPX however...

[Hardy Heinlin]

Jean-Philippe,

your two options have been on my plan for several years. There is an old thread on this subject in the forum somewhere.

I wasn't able to implement the aloft stuff because it would have delayed the release of PSX by another year or so. This stuff is still on my plan. But I cannot give a release date for such an update.


Regards,

|-|ardy


By the way, if anyone wants to experiment with PSX weather import and export -- all variables that are shown on the Instructor (including jetstream geometry) are available in PSX's Q network.

[Hardy Heinlin]

Such a "snapshot" is already partially available by requesting an upper winds download in the FMS after a route has been entered and activated. The predicted winds/temps can be seen for each waypoint on the RTE DATA pages.

Exactly!

This route data too is available via the Q network.

[JP59]

I wasn't able to implement the aloft stuff because it would have delayed the release of PSX by another year or so. This stuff is still on my plan. But I cannot give a release date for such an update.

I remember this thread where we talked about that already. I'm glad to see you plan to release such an update. Thank you so much for keeping PSX always improved and listen enthusiasts considerations.

[mk777]

The onus here could be on an avid user or PFPX developers to find a way to take the snapshot that is available and interpret it. In real life it isn't an accurate science and I think that to carry that forward is admirable, but at present, without making some pretty serious adjustments to the jet streams etc this is doesn't quite work as well as many would like. Especially given the "legs" of the bird.
The problem is, computer work with data inputs that are as accurate as the numbers going in. This has always been too accurate for my tastes in programs that use real weather.
I would think that given jet stream locations and pressure / temp information a program could produce simplified (read forecast) wind data. Given that PSX uses transitions to give the upper weather some continuity (which is my other gripe with real world weather) any two snapshots could be interpolated acceptably with more snapshots making more accurate interpolations.
This should give both sides of this debate a happy medium until the main man can develop his own undoubtably excellent solution.
The only remaining question for me then is how surface data is moved upwards to blend into the jet stream / temperature / pressure mix. Which is of course how the atmosphere generally operates.
Given some fairly rudimentary sets of data rules, surely the world snapshot could be extrapolated by a program to produce 6 hourly wind forecasts for flight planning software without having to be flight planning software itself. A plug-in for PFPX for want of a better phrase.
Any takers
Matt
Edit: Oh and of course, if your making short turnaround flights, although the winds aloft make minimal difference then, you can always note down the climb out winds and insert them in the descent wind boxes on the return leg

[Jeroen Hoppenbrouwers]

Just curious, where does PFPX get its aloft data from? Not so long ago, only TIFF raster plots (drawings of arrow fields) were available, which were not nice for computer interpretation. If we have a reliable aloft weather data source online, just like the METAR data, the rest becomes a lot easier.


Hoppie

[cagarini]

http://wiki.flightgear.org/Howto:Fetch_live_aloft_data

Also interesting to read this post in a thread about modeling of jetstream and fetching wings aloft for FG:

http://forum.flightgear.org/viewtopic.php?f=6&t=3059#p28013

From NOAA's GFS we can get:

http://www.ncdc.noaa.gov/oa/climate/igra/index.php

[JRBarrett]

Just curious, where does PFPX get its aloft data from? Not so long ago, only TIFF raster plots (drawings of arrow fields) were available, which were not nice for computer interpretation. If we have a reliable aloft weather data source online, just like the METAR data, the rest becomes a lot easier.


Hoppie

PFPX has several options for its winds aloft data. One can subscribe to the PFPX data server, which will provide winds aloft forecasts, current NAT tracks and current NOTAMS. Alternately, one can import winds from the weather data files downloaded by programs like ASN or Opus.

The ultimate source of worldwide winds aloft data is the GFS computer forecast model run three times daily by the U.S. NCEP (National Center for Environmental Prediction). The GFS model data may be freely downloaded from various NCEP servers, but the files are quite large, and require quite a bit of post-processing to extract the data fields of interest to an end-user.

Other national meteorlogical organizations have their own forecast models which are also run several times per day - the Canadian and European models are used by the NOAA, along with their own GFS model, in producing daily short and long-range weather forecasts. However, neither the Canadian or European model data is freely available for download by the general public, while the GFS data is

Programs like ASN, and the subscription PFPX data service, extract and process the winds forecast data from NCEP, and then insert the data onto their servers for download by their customers running the client programs.

The OPUS FSX weather injection program by contrast, fetches the data directly from the NCEP network on the end-user's own computer on an ad-hoc basis, processes the forecast data and then injects it into FSX.

The actual GFS model data is XYZ grid-based - with resolutions ranging from every degree of latitude and longitude, (for the X and Y axes) down to grids just a few KM on a side. The Z axis consists of vertical levels ranging from the surface up to about 60,000 feet.

[Ray_CYYZ]

I get the logic of being able to tie in real world weather but how on earth do you handle PSX's built in world where Hardy has invented a saved flight that you can come back to anytime you want and fly over and over again with exactly the same conditions?

With direct weather injection, saving a flight to come back to it later becomes impossible as the weather injection service is going to replace that weather with current real world each time you load the situation.


Is there the capabilities within these products to dump a global weather model snapshot for the purposes of replay?

[cagarini]

And further to Ray's post,

I have many times debated this theme, and the more I think about it the more I prefer to have a standalone weather model, provided it is sophisticated enough to give me weather patterns according to date and place around World.

I believe that's exactly what we have in PSX, where HH developed from scratch his own World wide Weather Model, with enough sophistication to provide us with the most diverse weather situations, and at the same time allowing to use RW METAR data, that will blend with it's own modeled data.

For me, I honestly see no purpose in trying to replicate aloft weather conditions, specially because they'll always be, after all, forecast-based...

[HercMighty]

I think that the main problem where people are looking is in flight planning.

PFPX is a great tool and provides a lot of realism that people are looking for, and why they are using this sim.

I understand that things are not going to match exactly, and we wouldn't want them to, but if PSX and PFPX are using information from the same sources and calculating their respective outputs, people just like real world pilots are looking for things to match up.

For instance a Pilot will I believe match that the plane is reporting the current fuel amount at a given waypoint correct? And if it is off by a large margin, will do other checks to ensure that there isn't something wrong. Is it possible to have a fuel problem the plane cannot detect? With correct weather you can also operate as a real airline would with regards to fuel management.

Sure we can use free programs and get a "route" but that is not the whole idea behind PFPX and not the only thing it excels at. PFPX with Topcat takes a lot of the planning things real world airlines do and gives it to us, though if things are synced up weather wise then it becomes worthless as anything beyond a "route planner".

[Xavier]

What about the other way around ? PFPX being made able to process weather file provided by PSX.
That would allow accurate/realistic matching (winds aloft prediction being just that : prediction, not measurements) hence realistic flight dispatching, while still letting a possibility for the user to decide what type of weather he wants to be facing : I for one doesn't necessarily look for real weather input as I may want to train specific weather conditions on my sim session (of course it would still allow real weather downloaded by PSX to be sent to PFPX for flight planning).

But I guess this would have more to be discussed with the PFPX guys...

[Ray_CYYZ]

From a logic standpoint, the external application needs to provide the feed, just as real world data can be the feed. It sounds like Hardy has created all the hooks with his Qcodes and TCP/IP interface which is normally the nightmare of peaking and poking directly into memory addresses.

The next step is really for the add on developers to understand they have a nice captive audience of people who have money should their product make an injector.

While it is nice to see Hardy always willing to take another thing onto his overflowing plate, it really isn't up to him to make their products sell for them unless he has some fat kick backs coming his way.  

[Will]

I prefer to have a standalone weather model, provided it is sophisticated enough to give me weather patterns according to date and place around World.

I believe that's exactly what we have in PSX, where HH developed from scratch his own World wide Weather Model, with enough sophistication to provide us with the most diverse weather situations, and at the same time allowing to use RW METAR data, that will blend with it's own modeled data.

For me, I honestly see no purpose in trying to replicate aloft weather conditions, specially because they'll always be, after all, forecast-based...

This is exactly right. PFPX uses a forecast... it attempts to forecast what you'll find in PSX. And it does a really good job. I flew from Beijing to Chicago the other day, and the wind direction was off by a bit here and there, as was the wind speed, but PFPX's predictions were in the ballpark. And the variations ended up canceling themselves out, so at the end of the trip the predicted fuel burn was spot on.

It's part of real-world flying that the actual in-flight winds are different than the forecast winds, so some variation is to be expected (and enjoyed).