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Use climatic data from MIL-STD-210 or MIL-HDBK-310
[T, a, P, rho]
= atmosnonstd(height, atmosphericType, extremeParameter, frequency, extremeAltitude, action, specification)
[T, a, P, rho] = atmosnonstd(height, atmosphericType, extremeParameter, frequency, extremeAltitude, action, specification) implements a portion of the climatic data of the MIL-STD-210C or MIL-HDBK-310 worldwide air environment to 80 km geometric (or approximately 262,000 feet geometric). This implementation provides absolute temperature, pressure, density, and speed of sound for the input geopotential altitude.
This function holds all values below the geometric altitude of 0 m (0 feet) and above the geometric altitude of 80,000 m (approximately 262,000 feet). The envelope atmospheric model has exceptions where values are held below the geometric altitude of 1 km (approximately 3281 feet). It also has exceptions above the geometric altitude of 30,000 m (approximately 98,425 feet). These exceptions are due to lack of data in MIL-STD-210 or MIL-HDBK-310 for these conditions.
In general, this function interpolates temperature values linearly and density values logarithmically. It calculates pressure and speed of sound using a perfect gas relationship. The envelope atmospheric model has exceptions where the extreme value is the only value provided as an output. In these cases, the function interpolates pressure logarithmically. These envelope atmospheric model exceptions apply to all cases of high and low pressure, high and low temperature, and high and low density. These exceptions exclude the extreme values and 1% frequency of occurrence. These exceptions are due to lack of data in MIL-STD-210 or MIL-HDBK-310 for these conditions.
A limitation is that MIL-STD-210 and MIL-HDBK-310 exclude from consideration climatic data for the region south of 60 degrees S latitude.
This function uses the metric version of data from the MIL-STD-210 or MIL-HDBK-310 specifications. A limitation is some inconsistent data between the metric and English data. Locations where these inconsistencies occur are within the envelope data for low density, low temperature, high temperature, low pressure, and high pressure. The most noticeable differences occur in the following values:
For low density envelope data with 5% frequency, the density values in metric units are inconsistent at 4 km and 18 km. In addition, the density values in English units are inconsistent at 14 km.
For low density envelope data with 10% frequency, the density values in metric units are inconsistent at 18 km. In addition, the density values in English units are inconsistent at 14 km.
For low density envelope data with 20% frequency, the density values in English units are inconsistent at 14 km.
For high-pressure envelope data with 10% frequency, the pressure values at 8 km are inconsistent.
T |
Array of m-by-1 temperatures, in kelvin. This function interpolates temperature values linearly. |
a |
Array of m-by-1 speeds of sound, in meters per second. This function calculates speed of sound using a perfect gas relationship. |
P |
Array of m-by-1 pressures, in pascal. This function calculates pressure using a perfect gas relationship. |
rho |
Array of m-by-1 densities, in kilograms per meter cubed. This function interpolates density values logarithmically. |
Calculate the nonstandard atmosphere profile. Use high density occurring 1% of the time at 5 km from MIL-HDBK-310 at 1000 m with warnings for out-of-range inputs:
[T, a, P, rho] = atmosnonstd( 1000,'Profile','High density','1%',5 ) T = 248.1455 a = 315.7900 P = 8.9893e+004 rho = 1.2620
Calculate the nonstandard atmosphere envelope with high pressure. Assume that high pressure occurs 20% of the time from MIL-STD-210C at 1000, 11,000, and 20,000 m with errors for out-of-range inputs:
[T, a, P, rho] = atmosnonstd([1000 11000 20000],'Envelope', ... 'High pressure','20%','Error','210c' ) T = 0 0 0 a = 0 0 0 P = 1.0e+004 * 9.1598 2.5309 0.6129 rho = 0 0 0
Global Climatic Data for Developing Military Products (MIL-STD-210C), 9 January 1987, Department of Defense, Washington, D.C.
Global Climatic Data for Developing Military Products (MIL-HDBK-310), 23 June 1997, Department of Defense, Washington, D.C.
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