atmosisa

Use International Standard Atmosphere model

Syntax

[T, a, P, rho] = atmosisa(height)

Description

[T, a, P, rho] = atmosisa(height) implements the mathematical representation of the International Standard Atmosphere values for ambient temperature, pressure, density, and speed of sound for the input geopotential altitude.

This function assumes that temperature and pressure values are held constant for both:

• Below the geopotential altitude of 0 km

• Above the geopotential altitude of the tropopause (at 20 km)

Examples

Calculate International Standard Atmosphere at One Height

Calculate the International Standard Atmosphere at 1000 m.

[T, a, P, rho] = atmosisa(1000)

T = 281.6500

a = 336.4341

P = 8.9875e+04

rho = 1.1116

Calculate International Standard Atmosphere at Multiple Heights

Calculate the International Standard Atmosphere at 1000, 11,000, and 20,000 m.

[T, a, P, rho] = atmosisa([1000 11000 20000])

T = 1×3

  281.6500  216.6500  216.6500

a = 1×3

  336.4341  295.0696  295.0696

P = 1×3
104 ×

    8.9875    2.2632    0.5475

rho = 1×3

    1.1116    0.3639    0.0880

Input Arguments

height — Geopotential heights

m-by-m array

Geopotential heights, specified as an m-by-m array.

Data Types: double

Output Arguments

T — Temperatures

m-element array

Temperatures, returned as an m-element array, in kelvin.

a — Speeds of sound

m-element array

Speeds of sound, returned as an m-element array, in meters per second. The function calculates speed of sound using a perfect gas relationship.

P — Pressures

m-element array

Pressures, returned as an m-element array, in pascal.

rho — Densities

m-element array

Densities, returned as an m-element array, in kilograms per meter cubed. The function calculates density using a perfect gas relationship.

References

[1] U.S. Standard Atmosphere, 1976. U.S. Government Printing Office, Washington, D.C.