Turbulence Offset C288

[VOZzer]

Hi Pete,

I'm having a bit of trouble with Offset C288.

Firstly, my understanding is that this offset provides the turbulence reading for the current cloud layer.

If this is correct, then I cannot understand the strange numerical readings I am experiencing from this offset.

This is what I get:

Turbulence set to NONE = 0

Turbulence set to LIGHT = 2?

Turbulence set to MODERATE = 3

Turbulence set to HEAVY = 0?

Turbulence set to SEVERE = 4

I'm a bit conused why it counts up 0,2,3,0,4. I thought that this offset functions in a similar manner to the precipitation offset 04CB; which just tells me the precipitation rate at current cloud level.

Any ideas?

Kindest regards,

Jack

[Pete Dowson]

I'm having a bit of trouble with Offset C288.

Firstly, my understanding is that this offset provides the turbulence reading for the current cloud layer.

Where do you understand that from? That offset is part of a complete structure with multiple levels. You'd need to find the correct layer. The NWI cannot be used without some programming to work out where it is you want data.

Please use the "WeatherSet2" program to view data read via the NWI protocol, to check whatever it is you are doing.

I thought that this offset functions in a similar manner to the precipitation offset 04CB; which just tells me the precipitation rate at current cloud level.

No, that's not correct either. It's the precipitation at the lowest level. 04CB is one of the old FS98 offsets where there was only one level for precipitation.

I think you are getting yourself confused by all the weather data provided. There are several sets (all maintained, as best as can be, for backwards compatibility):

The FS98-compatible weather offsets in the 0E9A-0F8C area of offsets. That sufficed for FS98 and FS2000.

The Advanced Weather Interface, a protocol based around encoded offsets, designed for fS2002 ff, with localised weather readout and setting for the first time (i.e. weather stations)

The NWI, New Weather Interface, introduced with FS2004 and enhanced for FSX, to take advantages of the hugely expanded weather capabilities introduced in FS2004.

The latter two involve protocol exchanges for reading and writing, though some structures are also filled in by default, such as weather at the current aircraft position. However, those are still complete structures, with the layered data and so on. C288 seems to be part of the first cloud structure, for the lowest layer.

Please just check your readings and decide what it is you need. As I said, WeatherSet2 wil display the data for you, and of course FSUIPC weather logging will show you just about everything.

BTW you don't mention version of FS or version of FSUIPC. Please do so next time. If you are using FSX you might be more interested in the new offsets at 0E84-0E88 and 0E94-0E98.

Regards

Pete

[VOZzer]

Hi Pete,

Thanks for your reply.

I think I shall stick with the FS98/FS2000 Offsets for now; they are nice and simple. The NWI ones are a bit too much for me at the moment.

For the precipitation rate, I use Offset 04CB. What is the equivalent offset for turblence (ie shows the turbulence "at aircraft"). Can you reccommend which offset?

There is "lower cloud turbulence", and upper, for the turbulence rate. However, there isn't for precipitation (which is why it was easy for my to choose Offset 04CB). Which one should I use? Or will I have to switch between the two depending on what I want?

Jack

[Pete Dowson]

What is the equivalent offset for turblence (ie shows the turbulence "at aircraft"). Can you reccommend which offset?

There isn't one for FSUIPC3. One was added for FSX as I mentioned. The point is that it is dependent on your altitude and where the wind and cloud layers start and end.

With winds you'd need to work out which wind layer you are in then read its turbulence.

With clouds you can never really tell. If you have "few clouds" with turbulence you might actually be well outside the nearest cloud, but you can only tell that by looking out of the window. You can find if you are in a cloud layer by its lower and upper altitudes, as with winds, but that doesn't mean you are actually in a cloud. Even the FSX value provided can't distinguish those two conditions, and, worse, it has to guess the cloud upper altitude as FSX doesn't supply that value.

There is "lower cloud turbulence", and upper, for the turbulence rate.

That covers two out of the possible n cloud layers -- but one of those should apply to the aircraft altitude, as I think i made one change accordingly. you'd need to check. Sorry, I've not used FS9 for 6 years now.

Regards

Pete

[VOZzer]

Hi Pete,

Which Turbulence Offset applies to the aircraft altitude? I'm using FSX, and the latest version of FSUIPC (downloaded 3 days ago).

I tried to use FSInterragator to locate the offset, and the "Offsets Status" PDF manual, but I cannot find it.

Please could your reccommend an offset for me test?

Regards,

Jack

[Pete Dowson]

Which Turbulence Offset applies to the aircraft altitude? I'm using FSX, and the latest version of FSUIPC (downloaded 3 days ago).

In FSUIPC4 you can get wind and cloud turbulence relevant to the aircraft altitude in the offsets I referred you to in a previous reply, i.e.

If you are using FSX you might be more interested in the new offsets at 0E84-0E88 and 0E94-0E98.

I tried to use FSInterragator to locate the offset, and the "Offsets Status" PDF manual, but I cannot find it.

Do NOT ever use FSInterrogate to find or read details of offsets. I simply cannot keep the data in that up to date. It is simply a tool for YOU to use to experiment with reading and writing offsets, and ANYONE can edit its data.

The offsets I referred you to are most certainly documented in the current FSUIPC Offsets Status document, the one for FSUIPC 4.70. Maybe you are looking at an out of date copy?

Regards

Pete

[VOZzer]

Hi Pete,

I tried some of your reccommended offsets (such as 0E84).

I am still struggling to get a sensible reading. For some weird reason, the turbulence logically goes up in value (ie, 155, 216) as the turbulence setting increases.

However, when I set the turbulence to "heavy", ALL turbulence offsets read "0".

I shall keep testing (BTW; I have downloaded the new FSUIPC SDK so I'm fully up-to-date on the documentation).

Jack

[Pete Dowson]

I am still struggling to get a sensible reading. For some weird reason, the turbulence logically goes up in value (ie, 155, 216) as the turbulence setting increases.

However, when I set the turbulence to "heavy", ALL turbulence offsets read "0".

155 isn't possible, actually. It uses only values 72, 144, 216 and 252 for light, moderate, heavy, severe..

Why aren't you using logging? It is provided in FSUIPC specifically to help folks debug their programs and work out what is going on. Also if you show me the log it would make it much easier and faster for me to help you!

You should also use WeatherSet2 to read the weather at the aircraft (it uses the NWI so shows all layers). The turbulence values there run 0-4 I think.

I've tried setting assorted cloud turbulences in FS, but it is hard to get higher values to stick -- I think you need to get other parts of the weather set appropriately too. I think you may be seeing the result of FS's "semi-intelligent" dynamic weather system. For instance, I can't easily set a "light" value which sticks -- but it always goes directly to moderate, #2 (=144 in offset 0E88). If I set "heavy" or "severe" it sets initially, and 0E88 reports 216 or 252, but within a couple of seconds it is cleared down to 0. This is FSX -- it isn't maintaining the setting, the turbulence is stopping probably because it isn't consistent with other weather system settings. If you ask FSUIPC to monitor offset 0E88 to the log, or view the weather in WeatherSet2, you can see this.

Your best bet for testing is selecting the "major thunderstorm" theme. With that you get a lower cloud layer with "severe" (#4), showing 252 in 0E88, and a higher cloud later with "moderate" (#3) showing 216 in 0E88.

Pete