> The reason pressure-sea-level-inhg doesn't match the altimeter
setting is because it doesn't in real life.
> The altimeter setting
number is chosen so the altimeter reads the field elevation when on
Even descending to ground level, it's not matching. So either something's still off or I'm just not understanding.
In either case, I take it from your explanation that it's completely normal for an aircraft's altimeter, even if the "local" altimeter setting happens to be 29.92, to vary as much as a few thousand feet at cruise from their actual height above sea level -- and that the air temperature is the primary driving factor behind how much variation this will be.
In the meantime, I do see that the property I ought to be getting the displayed number from (which is supposed to represent the local altimeter setting, for controllers to announce over the ATC channels at appropriate times) is not /environment/pressure-inhg, but /environment/metar/pressure-inhg. I originally copied a bunch of that code from the ATC-sets in CVS (now git), but I don't have those installed locally anymore... so I wonder if the same corrections need to be made in those as well.
Thanks for the explanation / clarification...
Robert M. Shearman, Jr.
Transit Operations Supervisor,
University of Maryland Department of Transportation
also known as rmsjr@...