asp22 Posted December 19, 2016 Share Posted December 19, 2016 (edited) Does anyone know how wind speed at a given altitude is calculated? In an attempt to discover this, I created 3 wind profiles in the mission editor and took readings at various heights using an A-10C. all directions set to 0 Profile 1, ft - kts 33 - 10 1600 - 21 (automatically set) 6600 - 0 26000 - 0 Profile 2, 33 - 0 1600 - 0 6600 - 20 26000 - 0 Profile 3, 33 - 0 1600 - 0 6600 - 0 26000 - 20 I've attached a plot showing the speeds at various alt for the three profiles. I've discovered that between 33ft and 1600 ft a power law with a coefficient of 0.194 seems to be used, The rest looks like some sin/cos flavour but i can't quite get them to fit. If anyone has looked into this and knows the magical formulas i'd be interested. Thanks, ------------------------------------------------------------------------------------- Update: I have managed to produce a reasonable model and have stuffed it into an excel sheet I've also added a screen capture to give you an idea of what to expect should you choose to download it. I hope that the use is straight forward. You use the sheet 'Settings' to plug in values and 'Results' has the calculated values provided in a table. The sheet 'Maths' has, well, the maths.... apologies if you take a peek inside here; my excel skills need a bit of work.wind and temperature estimation tool.zip Edited December 22, 2016 by asp22 fix broken attachment 1 1 Link to comment Share on other sites More sharing options...
razo+r Posted December 19, 2016 Share Posted December 19, 2016 You can adjust the wind at certain altitudes by yourslefe Link to comment Share on other sites More sharing options...
asp22 Posted December 19, 2016 Author Share Posted December 19, 2016 razo+r. I think there is a misunderstanding. I understand that it is possible to change wind speeds at certain altitudes. I'm interested in the model that DCS World uses to create a wind profile from the 3 values specified in the mission editor. Link to comment Share on other sites More sharing options...
funkyfranky Posted December 19, 2016 Share Posted December 19, 2016 Good question, I'd be interested as well. A warrior's mission is to foster the success of others. i9-12900K | MSI RTX 3080Ti Suprim X | 128 GB Ram 3200 MHz DDR-4 | MSI MPG Edge Z690 | Samung EVO 980 Pro SSD | Virpil Stick, Throttle and Collective | MFG Crosswind | HP Reverb G2 RAT - On the Range - Rescue Helo - Recovery Tanker - Warehouse - Airboss Link to comment Share on other sites More sharing options...
fitness88 Posted December 19, 2016 Share Posted December 19, 2016 Does the mission editor indicate air speed direction from where it's coming or where it's going? Also how does ATC indicate air speed direction? Link to comment Share on other sites More sharing options...
FUgaijin Posted December 19, 2016 Share Posted December 19, 2016 wind direction is always where it is coming from. the ATC just takes what it is set at and reads it back. My Setup: HOTAS Warthog, Saitek Combat Pro Rudders, Trackir 5, i Control w/ipad, powered by Alienware Aurora ALX i7 3930k oc 4.2, dual 980s, 16gb Ram. Link to comment Share on other sites More sharing options...
grunf Posted December 19, 2016 Share Posted December 19, 2016 Does the mission editor indicate air speed direction from where it's coming or where it's going? Also how does ATC indicate air speed direction? Mission editor and briefing shows the direction the wind is blowing to. ATC on final gives the direction the wind is blowing from. Link to comment Share on other sites More sharing options...
fitness88 Posted December 20, 2016 Share Posted December 20, 2016 Mission editor and briefing shows the direction the wind is blowing to. ATC on final gives the direction the wind is blowing from. What about the 'briefing screen' I take it that it and all other indicators in the sim are where the wind is blowing from. Link to comment Share on other sites More sharing options...
grunf Posted December 20, 2016 Share Posted December 20, 2016 What about the 'briefing screen' I take it that it and all other indicators in the sim are where the wind is blowing from. The briefing screen also shows direction to. AFAIK the only thing that gives the direction the wind is blowing from is ATC during the landing clearance. You can check it by placing a windsock. :) Link to comment Share on other sites More sharing options...
fitness88 Posted December 20, 2016 Share Posted December 20, 2016 The briefing screen also shows direction to. AFAIK the only thing that gives the direction the wind is blowing from is ATC during the landing clearance. You can check it by placing a windsock. :) WOW more confusion :helpsmilie: too bad it's not standardized. Link to comment Share on other sites More sharing options...
asp22 Posted December 20, 2016 Author Share Posted December 20, 2016 Looks like this thread has gone on a bit of a tangent. :) What grunf has said is true; mission editor: direction the wind is blowing towards (eg. 0) briefing: direction the wind is blowing towards. (0) In flight: direction the wind is coming from. so it is coming from 180 and trying to push you towards 0. Regarding the wind profile, I think that sin/cos wave bits are modelled by Bezier curves. I've had a quick play and i can get a reasonable fit. I'll test it out to see if it can predict other profiles and report back. Link to comment Share on other sites More sharing options...
asp22 Posted December 20, 2016 Author Share Posted December 20, 2016 Bezier curves seem to work. I used a cubic variant which gives a reasonable estimate; I wonder if a higher order improves things I created the following wind profile and took readings from 20 to 30000 ft 33ft - 0 deg - 10 kts 1600ft - 0 deg - 21 kts 6600 - 90 deg - 30 kts 26000 - 180 deg - 40 kts I then used the model to estimate the same profile. Results are attached. I've not corrected for the magnetic variation but results seem pretty good as a first approximation. I'll upload an excel sheet as soon as I've tidied it up. 2 Link to comment Share on other sites More sharing options...
asp22 Posted December 21, 2016 Author Share Posted December 21, 2016 I've updated the first post to include the excel sheet of the model. Link to comment Share on other sites More sharing options...
Ironhand Posted December 21, 2016 Share Posted December 21, 2016 I've updated the first post to include the excel sheet of the model. I got an empty file when I downloaded the Excel sheet. YouTube Channel: https://www.youtube.com/channel/UCU1...CR6IZ7crfdZxDg _____ Win 10 Pro x64, ASUS Z97 Pro MoBo, Intel i7-4790K, EVGA GTX 970 4GB, HyperX Savage 32GB, Samsung 850 EVO 250 GB SSD, 2x Seagate Hybrid Drive 2TB Raid 0. Link to comment Share on other sites More sharing options...
asp22 Posted December 22, 2016 Author Share Posted December 22, 2016 Ah, thanks Ironhand. It was indeed broken and I've correct this. Please try once more. Link to comment Share on other sites More sharing options...
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