# Documentation

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# propagationModel

Create RF propagation model

## Syntax

``pm = propagationModel(modelname)``
``pm = propagationModel(___,Name,Value)``

## Description

````pm = propagationModel(modelname)`creates an RF propagation model for the specified model. NoteSignal strength is computed using a propagation model that disregards the curvature of the Earth, terrain, or other obstacles. ```

example

````pm = propagationModel(___,Name,Value)` sets properties using one or more name-value pairs. For example, ```pm = propagationModel('rain','RainRate',96)``` creates a rain propagation model with a rain rate of 96 mm/h. Enclose each property name in quotes.```

## Examples

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```tx = txsite('Name','MathWorks Apple Hill',... 'Latitude',42.3001, ... 'Longitude',-71.3504, ... 'TransmitterFrequency', 2.5e9); rx = rxsite('Name','Fenway Park',... 'Latitude',42.3467, ... 'Longitude',-71.0972); ```

Create the propagation model for a heavy rainfall rate.

```pm = propagationModel('rain','RainRate',50) ```
```pm = Rain with properties: RainRate: 50 Tilt: 0 ```

Calculate the signal strength at the receiver using the rain propagation model.

```ss = sigstrength(rx,tx,pm) ```
```ss = -82.2937 ```

## Input Arguments

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Type of propagation model, specified as one of the following:

• `'freespace'` - Free space propagation model

• `'rain'` - Rain propagation model

• `'gas'` - Gas propagation model

• `'fog'` - Fog propagation model

• `'close-in'` - Close-in propagation model

You can use the following functions on RF propagation models:

• `range` - Calculate the range of the radio wave under different propagation scenarios.

• `pathloss` - Calculate the path loss between the transmitter and receiver sites under different propagation scenarios.

Data Types: `char`

### 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 single quotes (`' '`). You can specify several name and value pair arguments in any order as `Name1,Value1,...,NameN,ValueN`.

Example: `'RainRate',96`

#### Rain

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Rain rate, specified as a positive scalar in millimeters per hour (mm/h).

#### Dependencies

To specify `'RainRate'`, you must specify the `'rain'` propagation model.

Data Types: `double`

Polarization tilt angle of the signal, specified as scalar in degrees.

#### Dependencies

To specify `'Tilt'`, you must specify the `'rain'` propagation model.

Data Types: `char`

#### Gas

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Air temperature, specified as a scalar in Celsius (C).

#### Dependencies

To specify `'Temperature'`, you must specify the `'gas'` propagation model.

Data Types: `double`

Dry air pressure, specified as a scalar in pascals (Pa).

#### Dependencies

To specify `'AirPressure'`, you must specify the `'gas'` propagation model.

Data Types: `double`

Water vapour density, specified as a scalar in grams per cubic meter (g/m^3).

#### Dependencies

To specify `'WaterDensity'`, you must specify the `'gas'` propagation model.

Data Types: `double`

#### Fog

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Air temperature, specified as a scalar in Celsius (C).

#### Dependencies

To specify `'Temperature'`, you must specify the `'fog'` propagation model.

Data Types: `double`

Liquid water density, specified as a scalar in grams per cubic meter (g/m^3).

#### Dependencies

To specify `'WaterDensity'`, you must specify the `'fog'` propagation model.

Data Types: `double`

#### close-in

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Free-space reference distance, specified as a scalar in meters.

#### Dependencies

To specify `'ReferenceDistance'`, you must specify the `'close-in'` propagation model.

Data Types: `double`

Path loss exponent, specified as a scalar.

#### Dependencies

To specify `'PathLossExponent'`, you must specify the `'close-in'` propagation model.

Data Types: `double`

Standard deviation of the zero-mean Gaussian random variable, specified as a scalar in decibels (dB).

#### Dependencies

To specify `'Sigma'`, you must specify the `'close-in'` propagation model.

Data Types: `double`

Number of data points of zero-mean Gaussian random variable, specified as an integer.

#### Dependencies

To specify `'NumPoints'`, you must specify the `'close-in'` propagation model.

Data Types: `double`