h
This parameter represents the altitude above mean sea level (MSL) in the imaginary "standard atmosphere" that is being modeled. In reality, atmospheric properties may vary with geographical location, weather, etc, but the use of a standard atmosphere model allows aerospace engineers and others to have a common ground for describing how atmosphereic properties such as pressure and temperature typically vary with altitude. An atmosphere model is provided as an algorithm where you provide altitude and the ratio of pressure at altitude with that at sea level , ratio of temperature at altitude and at sea level, and the ratio of density at altitude and at sea level are calculated. From that information, all other atmospheric properties can be calculated. This atmosphere information can then be used to help calculate various airspeeds and other useful information.
The following methods are used by this program to calculate the altitude:
Where is the speed of sound at sea level under standard conditions.
Where is the ratio of specific heats for air (1.4), and
is the speed of sound at sea level.
Modified: October 13, 2003