Now that the environment subsystem can manage its own atmosphere model (at least up to 60,000 ft or so), I've added an option to use that model instead of the built-in model in each FDM (the default is still to let the FDM manage the atmosphere). If you run with
fgfs --prop:/environment/params/control-fdm-atmosphere JSBSim and YASim will bypass their own atmosphere models use the values from the environment subsystem. Currently, YASim seems to be working fine with this after a few lines of code changes, but JSBSim is not. JSBSim has built-in support for an external atmosphere, and the values seem to be getting through OK (after removing some spurious set_* methods), but the trimming routine gets caught in a loop. I'd be very grateful if Tony and others could look at this and figure out what the problem might be. Why use an external atmosphere model at all? Of course we want to be able to control the atmosphere rather than always flying at the equivalent of 15 degC temperature, 28.5 inHG, and 0.00237 slugs/ft^3 density at sea level. We could do that by providing the sea-level defaults and letting the FDM's atmosphere models calculate the values at altitude (it would also require a few lines of code change), but unfortunately, the FDMs are not the only subsystems that need atmosphere information -- we also need it for the some of the instruments, for the engine model (which might not always be built-into the FDM), for cabin pressurisation, and for weather reports like the ATIS, for icing, and who knows what else. 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
