Fig. 28 – Example of calculated measurement configuration of type "Dew point temperature"
4.2.3.7 Barometric pressure at sea level (QNH)
QNH is the value of the pressure reported at sea level from the one measured at a certain location,
considering the standard atmosphere. Since the standard formula has not yet been officially defined, Alpha-
Log proposes the choice of three different types of calculation:
➢ QNH – WMO Table
➢ QNH – ISA
➢ QNH – ICAO
The formula of type QNH - WMO Table corresponds to:
QNH = A + B * QFE
where A and B are standard parameters based on the measurement point elevation and defined by WMO
via Table 3.10 (ref. "International Meteorological Tables - WMO No. 188 TP. 94 - 1966") and QFE is the value
of relative true atmospheric pressure (measured) to the measuring point itself.
To Next Page
Loading...
