Curt asks: > Ok, so within flightgear, given a 'true' altitude, how can I compute > the correct flight-level / pressure-altitude for display on the > transponder?
The simple answer is that you ask the static port for the air pressure, which in turn will ask the environmental module what the local air pressure is and then apply fudge factors to correct for mounting location and such. The result, which is also needed by the altimeter instrument and the VSI, is simply interpolated through the official ICAO lookup table. Then, when the environmental module turns out to be giving inaccurate answers, we go in and fix that up till it works well enough. We can talk about that later, but I think it already got fixed earlier this year. If you don't have the official lookup table handy, a short term hack while we track it down is to divide by 29.92, take the log, divide by the log of 2, multiply by 18000. It's close enough for development. _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
