> Bah humbug. Engineers, seeing that there were two incompatable > standards simply choose to break the one normally seen by people who > should be able to understand the problem and adapt. Obviously, in this > case, they chose the wrong group. :)
Ha! Someone made the suggestion that we are doing this bass-ackwards. I disagree. We are talking about simulating an aircraft, about an aircraft-centric phenomena, and about a phenomena that is normally reported by humans in a particular way. Sitting on the runway, pointed with a heading of 20 degrees, and with a wind of 20 knots from 20 degrees (as is normally reported, that is, the *from* direction is given), the aircraft sees 20 knots headwind. This equation in FGTranslation shows this nicely: vAeroUVW = vUVW + State->GetTl2b()*Atmosphere->GetWindNED(); I know that the wind vector that originates in the NED axis points *at* 200 degrees and that the north component of this vector would be a negative number. But, what happens if you add the aircraft velocity and the wind velocity vectorially? You sure don't get the aircraft total sensed velocity vector. This approach we have taken is a compromise between what is easily understandable by most people when it comes to wind speed and what makes sense in a mathematical sense (see the above equation). Of course you can do it a couple of ways. It just needs to be documented. We have fallen short there, apparently. Jon _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
