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US Standard Atmosphere Equation
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Source：Internet Author：Unknow Pubdate：2008-04-02
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bstjs (Geotechnical)
18 Feb 05 19:23
I am looking for an equation (using the US standard atmosphere) that will allow me to calculate pressure at any altitude in the troposphere (< 11km) when I know the temperature and pressure at another altitude. Standard temperature lapse rate (-6.5K/km) can be assumed or different value to be input.
airmail (Aeronautics)
9 Mar 05 12:37
Hi bstjs.
I know the expression that gives you the relation between pressure at an altitude "z" for ISA (International standard atmosphere). I suppose that it be the same as US standard atmosphere. Here it goes:
Pz=Po*[(Tz/To)^(-g/R*k)]
Being:
Pz: pressure at a determined height (m)
Po: pressure at sea level (101325 N/m^2)
Tz: temperature at "z" height. In troposphere: Tz=To+k*z
To: temperature at sea level (288 K is used)
g: gravity (9.8 m/s^2) 字串6
R: gas constant (In air medium, take 287 m^2/(s^2)K
k: constant value ; take -6.5*(10^(-3)) K/m
I hope it be useful.
bstjs (Geotechnical)
15 Mar 05 10:38
In my case,I don't want to assume stamdard temperature and pressure at sea level (since this is usually not the case). I wish to use the information I have to improve my estimate of pressure at any other height (including sea level).
vorwald (Aerospace)
18 Mar 05 13:44
This link has a set of equations for standard atmosphere in the lower altitude, see page 4.
http://web.usna.navy.mil/~dfr/flttst0.pdf
Here is another link
http://wahiduddin.net/calc/density_altitude.htm
（Click：）
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