How to Effectively Monitor SD-WAN and SASE Environments with ThousandEyes
The standard atmosphere
1. Chapter 3 The Standard Atmosphere 1.Structure Of The Atmosphere ● Atmosphere is the air envelope surrounding the earth ● Air is a mixture of several gases, where Oxygen represents (21%) ,Nitrogen (78%), and other gases (1%) of the total volume. ● Up to about 90 km altitude, composition of air is the same (the homosphere ( ● Above about 90 km, composition varies with altitude (the heterosphere) as shown in figure.
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3. ● The atmosphere is divided into several layers according to temperature variation with altitude Why do we study the atmosphere? ● For the design and performance determination of any flying vehicle (airplane, missile, satellite,….etc), knowledge of the vertical distribution of pressure, temperature, and density of air is required. ● The properties of the real atmosphere never remain constant at any particular time or place. ● Consequently, a hypothetical model is employed as an approximation to what may be expected. This model is known as the standard atmosphere .
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7. h a R h G Surface of earth ( Sea level) Definition of altitude By definition : dp = - ρ g dh G = - ρ g o dh Then : dh/dh G = g / g o