Jim Allan Posted January 20, 2015 at 01:29 AM Posted January 20, 2015 at 01:29 AM Hey All, Not that it makes a hill of a lot of beans, but I'm just wondering where ES gets the altitude from? I've been seeing discrepancies from time to time, where I will show 15600' and the pilot will be 15000'. Does ES get the info from the pilots software or does it interpolate altitude from the local altimeter set from metars? Thanks, Jim Allan CZQM/QX Chief Instructor If you don't know the answer...at least make it sound convincing Link to comment Share on other sites More sharing options...
Sebastien Bartosz Posted January 20, 2015 at 02:03 AM Posted January 20, 2015 at 02:03 AM The servers know what altitude the pilot is at ASL, as opposed to the real world where that information is transmitted from the transponder. So if the pilot reports hes at 15000 (what he sees) But you see 15600, that means his altimeter is not correctly set. New York ARTCC Link to comment Share on other sites More sharing options...
Miguel Frias Posted January 20, 2015 at 03:48 PM Posted January 20, 2015 at 03:48 PM For every hPa that is incorrectly set there is an offset of around 30ft. So if you see him at 15600ft it means he has his altimeter set with a 600/30=20 hPa difference which means it's set to (1013-20=993) hPa. Means he had his QNH set to 993 and then forgot to adjust to standard altimeter 1013. In Euroscope this is also observable with the CLAM warning at the top of the plane's tag, indicating that the pilot's altitude (or altimeter) is incorrectly set. Miguel Frias Senior Instructor (I3) & Certified Pilot (P4), ZLA I-11 graduate Portugal vACC Training Director (ACCPT2), VATEUD Operations Director (VATEUD8) Portugal vACC, VATEUD, VATSIM Link to comment Share on other sites More sharing options...
Michael Pike Posted January 21, 2015 at 08:27 PM Posted January 21, 2015 at 08:27 PM But bear in mind it can also be caused by the pilot's FS using different weather to VATSIM. To be this far out, the most likely scenario is that his FS is not getting any weather injection for some reason. It will then be flying in an atmosphere of 1013 hPa but with the altimeter set correctly to 1033. ([Mod - Happy Thoughts]uming we are talking about a TA of 18000 ft.) This is solved by the pilot ignoring the QNH given by ATC and setting the altimeter to match his weather. (Pressing B in FSX). The figure displayed in ATC clients is sent from the pilot client. I understand, the pilot client sends the altitude AND the same figure corrected to a standard pressure of 1013. One of those figures is then displayed to the controller depending on the Transition Altitude set by the controller. I have no insider knowledge on this so if anyone who knows the details wants to correct any misinformation, I would be grateful if they did. Mike Pike VATSIM-UK Link to comment Share on other sites More sharing options...
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