# atmositu

Use ITU reference atmospheres

## Syntax

``[t,p,wvden] = atmositu(h)``
``[t,p,wvden] = atmositu(___,Name,Value)``
``atmositu(___)``

## Description

example

````[t,p,wvden] = atmositu(h)` calculates the International Telecommunication Union (ITU) standard atmospheric model and returns the atmospheric temperature `t`, pressure `p`, and water-vapor density `wvden`.```

example

````[t,p,wvden] = atmositu(___,Name,Value)` returns the atmospheric temperature, pressure, and water-vapor density with additional options specified by one or more name-value pairs. For example, `'LatitudeModel'`,`'High'` specifies a reference model for latitudes greater than 45°.```
````atmositu(___)` with no output arguments plots: Atmospheric temperature `t` versus altitude in linear scaleAtmospheric pressure `p` versus altitude in logarithmic x-scaleAtmospheric water-vapor density `wvden` versus altitude in logarithmic x-scale ```

## Examples

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Compute the atmospheric temperature, pressure, and water-vapor density for a mid-latitude area during winter. Specify an altitude range between `2` km and `88` km.

```h = (2:88).*1e3; [t,p,wvden] = atmositu(h,'LatitudeModel','Mid','Season','Winter')```
```t = 1×87 264.7771 260.2759 255.4229 250.2181 244.6615 238.7531 232.4929 225.8809 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 218.0000 221.3571 224.7142 228.0713 231.4284 234.7855 238.1426 241.4997 244.8568 248.2139 251.5710 254.9281 258.2852 261.6423 265.0000 265.0000 265.0000 265.0000 265.0000 ```
```p = 1×87 789.5947 689.4528 598.9723 518.1532 446.9955 385.4992 333.6643 291.4908 258.9787 223.5748 193.0107 166.6250 143.8464 124.1817 107.2053 92.5497 79.8976 68.9751 59.5458 51.4055 44.3781 38.3113 33.0739 28.5525 24.6492 21.2795 18.3705 15.8591 13.6911 11.8194 10.2037 8.8088 7.6045 6.5650 5.6675 4.8927 4.2238 3.6464 3.1479 2.7176 2.3461 2.0254 1.7485 1.5095 1.3031 1.1250 0.9712 0.8384 0.7238 0.6248 ```
```wvden = 1×87 1.7601 1.1320 0.6829 0.3875 0.2074 0.1049 0.0503 0.0230 0.0100 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ```

Plot the atmospheric temperature, pressure, and water-vapor density profiles for the same model.

`atmositu(h,'Latitude','Mid','Season','Winter')`

## Input Arguments

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Geometric heights corresponding to the altitude above mean sea level (MSL) in meters, specified as a row vector. The `atmositu` function returns `NaNs` for any input value outside of the interval [0,100].

Data Types: `double`

### Name-Value Pair Arguments

Specify optional comma-separated pairs of `Name,Value` arguments. `Name` is the argument name and `Value` is the corresponding value. `Name` must appear inside quotes. You can specify several name and value pair arguments in any order as `Name1,Value1,...,NameN,ValueN`.

Example: `atmositu(h,'LatitudeModel','Mid','Season','Winter')` specifies the mid-latitude model during winter.

Standard ground-level water-vapor density in g/m3, specified as a scalar. `VaporDensity` applies only when `LatitudeModel` is set to the default `'Standard'` model.

Data Types: `double`

Scale height in meters, specified as a scalar. `ScaleHeight`applies only when `LatitudeModel` is set to the default `'Standard'` model. For a dry atmosphere, set `ScaleHeight` to `6000`.

Data Types: `double`

Reference latitude model, specified as:

• `'Standard'` — This is the Mean Annual Global Reference Atmosphere (MAGRA) model that reflects the mean annual temperature and pressure averaged across the world.

• `'Low'` — Use this model for latitudes lower than 22°, with little seasonal variation.

• `'Mid'` — Use this model for latitudes between 22° and 45° that have seasonal profiles for summer and winter. You can specify a seasonal profile using the `Season` name-value pair.

• `'High'` — Use this model for latitudes greater than 45° that have seasonal profiles for summer and winter. You can specify a seasonal profile using the `Season` name-value pair.

Seasonal profile, specified as `'Summer'` or `'Winter'`. This argument is valid only when `LatitudeModel` is set to `'Mid'` or `'High'`.

## Output Arguments

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Atmospheric temperature in Kelvin, returned as a row vector.

Atmospheric pressure in hectopascals, returned as a row vector.

Atmospheric water-vapor density in g/m3, returned as a row vector.

## References

[1] International Telecommunication Union (ITU). "Reference Standard Atmospheres". Recommendation ITU-R P.835-6, P Series, Radiowave Propagation, December 2017.