Abstract:

ESDU 78012 gives methods for calculating properties of an atmosphere in which the variation of ambient temperature with height differs from that in the International Standard Atmosphere. Two cases are considered in which either the temperature is a linear function of geopotential or of pressure height. In each case equations are given relating geopotential to pressure height and vice versa. Where there is a non-linear variation of temperature, atmospheric layers in which the temperature variation can be treated as linear have to be chosen; an example shows the errors that are likely to be introduced by such an approximation. ESDU 68046 tabulates values of atmospheric properties in a Standard and Off-Standard Atmosphere while ESDU 72018 tabulates the properties in SI units but for heights in feet, the most commonly used height unit in aircraft operations. ESDU 77022 gives equations for calculating properties in a Standard or Off-Standard Atmosphere.