ATIS Update

[rexdriver]

Pete

I hope you can guide and / or help !

I have atttached a log of a flight I do regularly from Christchurch (NZCH) to Queenstown (NZQN) - and where every time as I approach NZQN I get the wrong / different ATIS data (QNH and wind) via an add-on program (FSX RealAtis) compared with what is the FSX Atis data (and hence the simulated conditions).

In the attached, RealAtis was broadcasting a northerly wind & QNH 1013mb, FSX Atis was broadcasting a southerly / 1020mb.

I understand that RealAtis is reading the weather through my FSUIPC4.5.

It is only after landing that the RealAtis broadcast changes to match the FSX (and apparently correct) broadcast.

I note on the fsuipc.log that the weather station being read as I approach NZQN is another station NZDN which is 100nm east.

I assume as NZQN has its own FSX atis that it is an ICAO station read by the real-time weather downloads.

Any comment / advice you may have would be appreciated.

Cheers

John

FSUIPC4.zip

[Pete Dowson]

In the attached, RealAtis was broadcasting a northerly wind & QNH 1013mb, FSX Atis was broadcasting a southerly / 1020mb.

The beginning of the log shows FSX teling FSUIPC4 that the weather at NZCH was as follows:

"NZCH&A36 252028Z 20907KT&D304NG 34711KT&A877NG 34811KT&A1791NG 34812KT&A2706NG 34816KT&A3620NG 34926KT&A5449NG 33531KT&A7278NG 32642KT&A9107NG 33546KT&A10326NG 32049KT&A11850NG 100KM&B-1536&D1994 CLR 14/09 08/-3&A877 07/01&A1791 03/-2&A2706 -1/-4&A3620 -12/-26&A5449 -24/-39&A7278 -37/-46&A9107 -48/-52&A10326 -62/-73&A11850 Q1020 ...

that's wind 209 at 7kt and QNH 1020.

At the end of the log, the nearest airport was NZDN with:

"NZDN&A1 252306Z 21007KT&D304MG 32622KT&A912MG 32824KT&A1826NG 33028KT&A2741NG 32029KT&A3655NG 31827KT&A5484NG 32041KT&A7313LG 32362KT&A9142LG 31974KT&A10361LG 32181KT&A11885NG 100KM&B-1501&D1958 CLR 14/09 08/-3&A912 06/-6&A1826 02/-4&A2741 -2/-12&A3655 -14/-25&A5484 -26/-33&A7313 -39/-48&A9142 -49/-49&A10361 -49/-49&A11885 Q1020 ...

i.e. wind 210 at 7kt, QNH also 1020.

Whilst the weather at the aircraft, at the end of the log, was:

"????&A0 252356Z 21207KT&D323LG 100KM&B-1500&D1959 CLR 11/04 Q1019 "

showing wind 212 at 7kt and QNH 1019.

FSX never provided any weather response for NZQN -- it sounds like it didn't have that listed as a weather station. The log shows this as:

2974110 WX Error: timed out, WX request type 3, ICAO=NZQN

and it is consistent, so not a fluke of timing or anything.

[NOTE: I just checked the weather station list for FSX -- it's the file called "weatherstationlist.BIN" in the same folder as your FSX.CFG file. There is no FSX weather station at NZQN! ]

RealAtis could get the weather AT NZQN by supplying the Lat/Lon instead of the ICAO ID -- the problem with the ICAO ID method is that it has to be sure there is a weather station with that ID. It sounds like the program is getting the default weather (standard QNH 1013, etc) when it fails to read a weather station (and presumably it isn't checking that its request even worked). This would be the GLOBal weather:

"GLOB&A0 000000Z 04004KT&D915NG 06614KT&A1830NG 06314KT&A3016NG 09024KT&A5490NG 33524KT&A6028NG 33731KT&A9150NG 14KM&B-500&D1000 14KM&B500&D100 80KM&B600&D100 32KM&B700&D100 48KM&B800&D100 48KM&B900&D100 64KM&B1000&D100 64KM&B1100&D1000 80KM&B1200&D1000 80KM&B2200&D1000 80KM&B3200&D9000 3CU050&CU000RLVN000N 2CI350&CI000FNVN000N 06/04 -2/-4&A904 -11/-13&A1828 -22/-24&A3014 -44/-46&A5448 Q1013 ...

showing wind 40 at 4kt and QNH 1013.

I note on the fsuipc.log that the weather station being read as I approach NZQN is another station NZDN which is 100nm east.

That, according to FSX, is the nearest weather station -- you'll note the word "nearest" in the log.

Regards

Pete

[rexdriver]

Pete

Thanks for your notes - and such an expedient reply.

Am I correct in understanding & given that the FSX atis I received at 50nm proved to be the weather on landing (almost):

a) the fsuipc.log is of weather at the aircraft being updated as it flies.

b) the FSX Atis broadcast is compiled separately for the destination ahead of the aircraft & where if that airport is not listed in weatherstationlist.bin, the FSX Atis uses lat/long to compile a broadcast.

Cheers

John

[Pete Dowson]

Am I correct in understanding & given that the FSX atis I received at 50nm proved to be the weather on landing (almost):

Let's stop there a moment. The log shows the wind and QNH at your departure airport AND at the "nearest weather station" to Queensland, the one you say is 100nm away, to be similar and probably close to whatever ATIS you received, so I would be surprised if the weather at Queensland was a lot different -- and the interpolated weather at the aircraft shows similar too. Not the same, as you say.

a) the fsuipc.log is of weather at the aircraft being updated as it flies.

ErPerhaps unsurprisingly, the weather logged by FSUIPC is actually what it is described as being in the log itself! There are English words (or abbreviations perhaps) which do tell you. Check the parts I show in red below, in these typical entries in your log:

Weather Read request (At Station) to area 3: ICAO="NZCH", Req=0

Weather Received (type 3 request, AtStation): "NZCH&A36 000000Z 04004KT&D915NG

(weather requested AT a specified station, in this case NZCH).

Weather Read request (Nr Station) to area 5: Lat=-45.02, Lon=168.74

Weather Received (type 5 request, Nearest): "NZDN&A1 252306Z 21007KT&D304MG ...

(i.e. nearest weather station to you, the aircraft you are flying! The Lat/Lon in the request is your aircraft's)

Weather Read request (Global set) to area 1: ICAO="GLOB"

Weather Received (type 1 request, AtStation): "GLOB&A0 000000Z 04004KT&D915NG ...

(i.e weather at a known station, or GLOBal weather, as here -- GLOB is FSX's special station ID for global (=default) weather)

Weather Read request (At Aircrft) to area 4: Lat=-45.02, Lon=168.74, Alt=358.9

Weather Received (type 4 request, Interpolated): "????&A0 252356Z 21207KT&D323LG

("At Aircrft" should be self explanatory. The Lat/Lon is the aircraft's, the response is Interpolated weather which FSX is setting AT the aircraft, for the Lat/Lon/Altitude given.)

FSUIPC4 reads GLOB and "At aircraft" weather at regular intervals, and weather at a requested station when requested. The weather data goes to different areas and can be read separately by programs. The FS98 compatible weather offsets reflect the weather at the aircraft, as they always have. If weather is requested for a non-existent station, as is happening with your utility, then FSUIPC4 supplies GLOB weather, but indicates this (the ICAO set with it will be GLOB, not the ICAO ID requested). Really FSUIPC has no choice -- it has no database of ICAO IDs, else it could look up the Lat/Lon and get interpolated weather. It is up to the utility to do that.

b) the FSX Atis broadcast is compiled separately for the destination ahead of the aircraft & where if that airport is not listed in weatherstationlist.bin, the FSX Atis uses lat/long to compile a broadcast.

Sorry, I've absolutely no idea what FS does in compiling its ATIS. I'm amazed it even provides a response to ATIS if there's no weather station listed. Are you using add-on scenery which adds the ATIS frequency, or is it included in FSX by default? If so I would have thought they would have included it in the weather station list.

Incidentally, I've really never used FS ATIS, in any version. I've been a long term user of Radar Contact, which compiles its ATIS from FSUIPC, and does it correctly (using Lat/Lon). ;-)

Regards

Pete

[rexdriver]

Pete

Thanks again...I think I understand (mostly).

My curiosity is, as yours, why Queenstown - which has an Atis in the real world - is included in FSX by default (airport & atis) yet is not listed in weatherstationlist.bin ??

Cheers

[Pete Dowson]

My curiosity is, as yours, why Queenstown - which has an Atis in the real world - is included in FSX by default (airport & atis) yet is not listed in weatherstationlist.bin ??

I think the list is determined by what Jeppesen supply -- the weather downloads FSX performs, as with FS9, are put together for them by Jeppesen. The file in the same folder as the FSX.CFG file is actually an updated copy of the installed one in FSX's "Weather" folder -- modified by any omissions or additions on the last FSXweather download -- but I note that Queensland isn't in the original install either.

Incidentally, it wasn't listed in FS9's file either.

Regards

Pete