# landreflectivity

Reflectivity of land clutter

## Syntax

``nrcs = landreflectivity(landtype,graz)``
``nrcs = landreflectivity(landtype,graz,freq)``
``[nrcs,hgtsd,beta0,vegtype] = landreflectivity(___)``

## Description

example

````nrcs = landreflectivity(landtype,graz)` returns the normalized radar cross section (`nrcs`) in meters squared for the specified land clutter type `landtype` at the grazing angle `graz`.`nrcs = landreflectivity(landtype,graz,freq)` specifies the transmitted frequency for the NRCS.`[nrcs,hgtsd,beta0,vegtype] = landreflectivity(___)` in addition to the NRCS returns: `hgtsd` — standard deviation of the surface height`beta0` — slope of the land type`vegtype` — vegetation type ```

## Examples

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Calculate NRCS, surface height standard deviation, land slope, and vegetation type. Specify an urban land type and a grazing angle of `10` degrees.

```graz = 10; [nrcs,hgtsd,beta0,vegtype] = landreflectivity("Urban",graz)```
```nrcs = 0.0549 ```
```hgtsd = 10 ```
```beta0 = 5.7296 ```
```vegtype = 'None' ```

## Input Arguments

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Surface land type, specified as a string of one of the allowed land types.

Example: `landtype = "Urban"`

Grazing angle, specified as a scalar or an N-length row vector of nonnegative grazing angles in degrees. Specifies the grazing angles of the clutter patch relative to the radar.

Example: `graz_angle = 10`

Transmitted frequencies, specified as a scalar or positive M-length vector.

Example: `freq = 7*10e9`

## Output Arguments

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Normalized radar cross section of the surface reflectivity, returned as either an N-length row vector or as an M-by-N matrix in linear units of meters squared. N is the length of the grazing angles `graz` and M is the length of the frequency vector `freq`.

Standard deviation of the surface height, returned as a scalar in meters.

Slope of the land type β0, returned as a scalar in degrees.

The vegetation type is a character array determined by the `landtype` input.

Land TypeVegetation Type

`Rugged Mountains`

`Trees` (dense)

`Mountains`

`Trees` (dense)

`Woods`

`Trees` (dense)

`Wooded Hills`

`Trees` (dense)

`Rolling Hills`

`Brush` (dense)

`Farm`

`Grass` (thin)

`Desert`

`Grass` (thin)

`Flatland`

`Grass` (thin)

`Metropolitan`

`None`

`Urban`

`None`

`Smooth`

`None`

## Limitations

This function assumes a Gaussian clutter model and that the reflectivity of land clutter is mostly independent of wavelength. The Gaussian model may fail to simulate the effects of some natural and most man-made structures, which are generally modeled separately as discrete clutter.

 Barton, David K. Radar Equations for Modern Radar. Norwood, MA: Artech House, 2013. 