Comparing Passive mode, and preset control mode

[HobAnagerik]

Hi,

I decided to run a comparison of Asobo live weather, AS passive mode, and AS preset control mode, with regard to wind speed, and gusts. This has left me with questions regarding exactly what Passive mode is actually doing. Below is a link to the thread:

https://forums.flightsimulator.com/t/2024-activesky-weather-program-main-thread/638086/494

You will see that I could make out no difference between Asobo live weather, and AS passive mode. The wind speed, and variation seemed nigh on identical to me, even down to the baked in, fake Asobo gust repeating pattern. Then switching to AS preset mode you see an immediate change.

My understanding of Passive was that it would give us the Asobo visuals with AS control over wind, gusts, up/down draughts etc. It was obviously not an extensive test, as I didn't try approaching any mountainous regions, or enter clouds, only testing ground wind.

Here is a graph from that thread, showing ambient wind at ground level. Three 120 second segments, beginning with Asobo live weather, then AS passive, then AS preset control. LiveFlightData can be found here: https://www.fsdeveloper.com/forum/resources/live-flight-data.255/

 

[Nimbostratus72]

My understanding of Passive was that it would give us the Asobo visuals with AS control over wind, gusts, up/down draughts etc.

Well your understanding is incorrect, the answer is in the manual, this is not what Passive mode does. Passive mode uses MSFS wxr (visually and wxr control), AS only controls the effects on the aircraft like turbulence

AS Preset control controls wxr (visually and control)

So that answers why you got the results above.

 

[HobAnagerik]

Thanks, that makes sense. So Passive mode is essentially useless as a half way house, giving you transition-less weather with more accurate wind. Thanks for the clarification. For most flights I've found a planned route gives pretty acceptable results with preset control mode.

A further set of tests would be comparing Asobo Live, with AS Passive, with respect to aircraft body acceleration on all three axes. Tests like flying into, and out of clouds, over ridges, and hills, and so on.

 

[Nimbostratus72]

Passive mode depicts all wxr using MSFS wxr, there is no difference to if you have MSFS wxr on Live

I use it mostly for the turbulence, as there is hardly any turbulence in MSFS, let alone in-cloud turbulence, in MSFS for airliners like the prosm737 I use.

 

[HobAnagerik]

The biggest difference I noticed was that with Asobo live weather there is this random, very rapid buffering whether you are in a cloud or not. The first ~220 seconds is me flying into, an out of clouds.

The image below shows Asobo live weather on the left, then AS present control at 50% turb. scaling from 500 to 900, then 100% turb. scaling from ~1020 seconds. The weird part of the graph is the sim paused as I switch to AS active preset. The little red hump is where I used the AP to direct me towards a storm cloud. Another little pause in data, where I adjusted the turbulence scaling from the default of 50 to 100. I already had turbulence at 100%, and was surprised to see the scaling at 50 not only as a default, but also since I had pressed that "realism mode" button. At around 1020 seconds or so you can can see the slightly larger trace than scaling at 50. Then a big jump as I enter the cloud at ~1090 seconds, then at ~1030 seconds back to either none or CAT.

The other thing that can be seen is that Asobo seem to concentrate on the X axis, whereas AS is on the Y axis. Anyone who has ever viewed their plane from behind in Asobo live weather will recognise that as the dog wagging its tail effect it gives.

 

[Nimbostratus72]

The other thing that can be seen is that Asobo seem to concentrate on the X axis, whereas AS is on the Y axis.

The y axis I understand was a deliberate change by AS to reflect realistic turbulence, as you know when you have had a turbulent flight you say it has been "bumpy", ie like on a bumpy road, or in other words, up/down (y axis) rather more than left/right (x axis), although there will also be some of the latter

 

[BU830]

Another difference is the altitude. When you switch from passive to preset mode you suddenly fly 1000ft too high and other way round 1000ft too low. Air pressure of 1013/2992 should be the same.

 

[Nimbostratus72]

That might be from something I remember reading that MSFS calculates True Altitude wherever you are (whether with QNH or QNE), which caused a problem initially flying on Vatsim. This was corrected for (probably by vatsim and others) but maybe this is something to do with it. If you try a flight in exactly Standard ISA conditions (ie temperature and pressure especially) is there then little difference?