Pressure settings
QFE: The atmospheric pressure read from a barometer on an airfield, which gives aerodrome pressure.
QNH: The barometric pressure at the airfield reduced to mean sea level, using the ISA International Standard Atmosphere, temperature at the airfield.
QFF: Barometric pressure at the surface reduced to mean sea level using the actual temperature at the surface.
QNE: The height indicated on landing at an airfield when 1013 mb is set on the altimeter.
RPS: A forecast valid for one hour, of the lowest QNH in any part of the region.
ISA pressure 1013,25 mb = 29,92 inches of mercury
