Originally Posted by
jmmoric
Rounding algorithm?? For what?
If it's the QNH/QFE, the decimal is always rounded down... so 1013.9 is given as 1013.
Oh, and the 1 hPa = appx. 30 feet.... that is only at ground level, due to the way an altimeter is set up, at 30.000 feet 1 hPa is roughly 70 feet. Which is the reason vertical separation is 2000 feet above FL290 (but is reduced in RVSM airspace with requirements on the altimeters of the aircraft flying there)
Doesn't that depend where your ground is?