Andy Ross writes: > Nonetheless, I think I found the problem. In converting the YASim > table to the new format, its values were re-encoded as deltas from sea > level conditions, with sea level pressure defined as 29.92 inches of > mercury. But in the FGEnvironment constructor, I see the following > initializer: > > pressure_sea_level_inhg(28), > > Now, 28 in. Hg is a reasonable sea level pressure. But it's not the > same one that the table is assuming. At sea level, it's off by only > about 2 inches. But at altitude, it's off by a whopping TWO inches! :)
Actually, the value being used is the one set in preferences.xml, 28.5, but you're still almost certainly right. I'll change both to 29.92, but there's more to consider. The idea is that users should be able to set any reasonable sea-level pressure and see reasonable behaviour -- that's why I set the tables up with deltas rather than absolute values. I can see, now, how that would be a problem at higher altitudes, but what should we see? If the altimeter setting at ground level is 28inHG or 31inHG, what would you expect at, say, 20,000 ft? Would a factor rather than an offset most appropriate? All the best, David -- David Megginson, [EMAIL PROTECTED], http://www.megginson.com/ _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
