Pavel Brodsky Posted July 9, 2015 at 06:44 PM Posted July 9, 2015 at 06:44 PM Hello, I have discovered one weird and annoying bug of Euroscope. Groundspeed in airctaft GS is probably not calculated from how far the airplane moves in certain time, but is rather just transfered via FSD protocol from the individual pilot client as a plan number, am I right? The point is - as long as everybody has everyhing alright, it works. But some folks (maybe 1 in 50 pilots) have some faulty sims (low FPS, etc) which causes the problem. Euroscope reads GS from their airctaft instruments and display this number on our screen. But because the pilot has faulty sim, he is physically moving much slower. The result is that you can see him doing for example 400 knots groundspeed, but his real distance traveled in 1 hour is not 400NM, but rather 250NM, or similar. You can also see that however he has high high groundspeed displayed in the label, his history dots are very close together, much closer than for other planes flying this GS. Request: we need the groundspeed number to be calculated from how far he moves in last moments (I dont know what time they calculate in real life, maybe few seconds). Picture attached. Compare history dots for both planes with their groundspeeds. Pavel Pavel Brodsky VACC-CZ Link to comment Share on other sites More sharing options...
Sebastien Bartosz Posted July 9, 2015 at 11:09 PM Posted July 9, 2015 at 11:09 PM For what it's worth, VRC also has the same issue. New York ARTCC Link to comment Share on other sites More sharing options...
Martin Loxbo Posted July 10, 2015 at 03:16 PM Posted July 10, 2015 at 03:16 PM I noticed this behaviour a few years ago and got the following reply from Gergely: The GS displayed in the TAG uses the following formula: - If there is a position report from the plane and the last report has a GS above 0 then it is displayed. - Otherwise the GS calculated by ES. Both can be inaccurate unfortunately: - The first depends on the pilot client not on ES. So I can not precisely define why they are different, bu I saw similar situations several times. - The second one can even be more inaccurate. The cause of that is the plane position data lacks a time stamp. So in ES I do not know the time elapsed between the position updates. I know only the time difference when I receive these data. Because of that I use a 30 seconds average when calculating GS and vertical speed. May be that 100 KTS are a bit high, but calculated speed may vary depending on when the clients receive the position updates. Martin Loxbo Director Sweden FIR VATSIM Scandinavia Link to comment Share on other sites More sharing options...
Ross Carlson Posted July 10, 2015 at 06:02 PM Posted July 10, 2015 at 06:02 PM When I wrote VRC, I ran into the same issue. I originally had it try to calculate the GS, but because of varying network lag, it fluctuated too much. I didn't want to do a 30 second average because while that would smooth out the fluctuations, it wouldn't make it any more accurate except for an aircraft that wasn't changing speed over the last 30 seconds. So VRC (and my other clients) just shows the GS reported by the pilot client. Developer: vPilot, VRC, vSTARS, vERAM, VAT-Spy Senior Controller, Boston Virtual ARTCC Link to comment Share on other sites More sharing options...
Pavel Brodsky Posted July 10, 2015 at 08:26 PM Author Posted July 10, 2015 at 08:26 PM Ok, thanks for replies - looks like unsolvable thing that is just another reason why we need new FSD protocol so much Pavel Pavel Brodsky VACC-CZ Link to comment Share on other sites More sharing options...
Recommended Posts