# atmosnonstd

Use climatic data from MIL-STD-210 or MIL-HDBK-310

## Syntax

``````[T,a,P,rho] = atmosnonstd(height,atmosphericType,extremeParameter,frequency,extremeAltitude)``````
``````[T,a,P,rho] = atmosnonstd(___,action)``````
``````[T,a,P,rho] = atmosnonstd(___,specification)``````

## Description

example

``````[T,a,P,rho] = atmosnonstd(height,atmosphericType,extremeParameter,frequency,extremeAltitude)``` 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). For exceptions on the envelope atmosphere model, see `atmosphericType`.```[T,a,P,rho] = atmosnonstd(___,action)``` specifies the action for out-of-range input. Specify `action` after all other input arguments. ```[T,a,P,rho] = atmosnonstd(___,specification)``` specifies the MIL-STD-210C or MIL-STD-310 climatic data. Specify `specification` after all other input arguments. ```

## Examples

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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+04 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+04 * 9.1598 2.5309 0.6129 rho = 0 0 0```

## Input Arguments

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Geopotential heights, specified as an m-by-1 array.

Data Types: `double`

Atmospheric data, specified as one of these values.

Atmospheric Data TypeDescription
`'Profile'`

Use for simulation of vehicles vertically traversing the atmosphere, or when you need the total influence of the atmosphere. Use this type for realistic atmospheric profiles associated with extremes at specified altitudes.

`'Envelope'`

Use for vehicles traversing the atmosphere horizontally, without much change in altitude. Use this type for extreme atmospheric values at each altitude.

Due to lack of data in MIL-STD-210 or MIL-HDBK-310 for these conditions, this atmospheric model has these exceptions:

• When extreme value is the only value provided as an output, the function interpolates pressure logarithmically. These 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.

• When values are held below the geometric altitude of 1 km (approximately 3281 feet).

• When values are above the geometric altitude of 30,000 m (approximately 98,425 feet).

Data Types: `string`

Atmospheric parameter for extreme value, specified as:

• `'High temperature'`

• `'Low temperature'`

• `'High density'`

• `'Low density'`

• `'High pressure'`

• `'Low pressure'`

#### Dependencies

`'High pressure'` and `'Low pressure'` are available only if `atmosphericType` is set to `'Envelope'`.

Data Types: `double`

Percent of time that extreme values can occur, specified as:

• `'Extreme values'`

• `'1%'`

• `'5%'`

• `'10%`

• `'20%'`

#### Dependencies

• `'Extreme values'`, `'5%'`, and `'20%'` are available only if `atmosphericType` is set to `'Envelope'`.

• When `atmosphericType` is set to `'Envelope'` and `frequency` is set to `'5%'`, `'10%'`, or `'20%'`, `atmosnonstd` outputs valid output only for temperature `T`, density `rho`, and pressure `P`. All other parameter outputs are zero.

Data Types: `double`

Geometric altitude in kilometers, specified as one of these values.

Altitude in KilometersAltitude in Feet
`'5'`16404 ft
`'10'`32808 ft
`'20'`65617 ft
`'30'`98425 ft
`'40'`131234 ft

Data Types: `double`

Action for out-of-range input, specified as:

• `'Error'` — Displays warning and indicates that the input is out of range.

• `'Warning'` — Displays error and indicates that the input is out of range.

• `'None'` — Does not display warning or error.

Data Types: `char` | `string`

Atmosphere model, specified as one of these values.

SpecificationDescription
`'310'`MIL-HDBK-310
`'210c'`MIL-STD-210C

Data Types: `double`

## Output Arguments

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Temperatures, returned as an m-by-1 array in kelvin. This function interpolates temperature values linearly.

Speeds of sound, returned as an m-by-1 array in meters per second. This function calculates speed of sound using a perfect gas relationship.

Pressures, returned as an m-by-1 array in pascal. This function calculates pressure using a perfect gas relationship.

Densities, returned as an m-by-1 array in kilograms per meter cubed. This function interpolates density values logarithmically.

## Limitations

• 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 and MIL-HDBK-310 specifications, resulting in some inconsistency 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 these 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.

 Global Climatic Data for Developing Military Products (MIL-STD-210C). Washington, DC: Department of Defense January 9, 1987.

 Global Climatic Data for Developing Military Products (MIL-HDBK-310). Washington, DC: Department of Defense, June 23, 1997.

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