# aer2ned

Transform local spherical coordinates to local north-east-down

## Syntax

``````[xNorth,yEast,zDown] = aer2ned(az,elev,slantRange)``````
``[___] = aer2ned(___,angleUnit)``

## Description

example

``````[xNorth,yEast,zDown] = aer2ned(az,elev,slantRange)``` transforms the local spherical azimuth-elevation-range (AER) coordinates specified by `az`, `elev`, and `slantRange` to the local north-east-down (NED) coordinates specified by `xNorth`, `yEast`, and `zDown`. Both coordinate systems use the same local origin. Each input argument must match the others in size or be scalar.```
````[___] = aer2ned(___,angleUnit)` specifies the units for azimuth and elevation. Specify `angleUnit` as `'degrees'` (the default) or `'radians'`.```

## Examples

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A sensor in an aircraft measures the AER coordinates of a nearby landmark. Find the NED coordinates of the landmark with respect to the aircraft, using the AER coordinates of the landmark with respect to the same aircraft.

First, specify the AER coordinates of the landmark. Specify the azimuth and elevation in degrees. For this example, specify the slant range in kilometers.

```az = 155.427; elev = -23.161; slantRange = 10.885;```

Then, calculate the NED coordinates of the landmark. The units for the NED coordinates match the units specified by the slant range. Thus, the NED coordinates are specified in kilometers.

`[xNorth,yEast,zDown] = aer2ned(az,elev,slantRange)`
```xNorth = -9.1013 ```
```yEast = 4.1617 ```
```zDown = 4.2812 ```

Reverse the transformation using the `ned2aer` function.

`[az,elev,slantRange] = ned2aer(xNorth,yEast,zDown)`
```az = 155.4270 ```
```elev = -23.1610 ```
```slantRange = 10.8850 ```

## Input Arguments

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Azimuth angles of one or more points in the local AER system, specified as a scalar, vector, matrix, or N-D array. Azimuths are measured clockwise from north. Specify values in degrees. To use values in radians, specify the `angleUnit` argument as `'radians'`.

Data Types: `single` | `double`

Elevation angles of one or more points in the local AER system, specified as a scalar, vector, matrix, or N-D array. Specify elevations with respect to the `xNorth`-`yEast` plane that contains the local origin. If the local origin is on the surface of the spheroid, then the `xNorth`-`yEast` plane is tangent to the spheroid.

Specify values in degrees. To use values in radians, specify the `angleUnit` argument as `'radians'`.

Data Types: `single` | `double`

Distances from the local origin, specified as a scalar, vector, matrix, or N-D array. Specify each distance as along a straight, 3-D, Cartesian line.

Data Types: `single` | `double`

Angle units, specified as `'degrees'` (the default) or `'radians'`.

## Output Arguments

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NED x-coordinates of one or more points in the local NED system, returned as a scalar, vector, matrix, or N-D array. Values are returned in the same units as the `slantRange` argument.

NED y-coordinates of one or more points in the local NED system, returned as a scalar, vector, matrix, or N-D array. Values are returned in the same units as the `slantRange` argument.

NED z-coordinates of one or more points in the local NED system, returned as a scalar, vector, matrix, or N-D array. Values are returned in the same units as the `slantRange` argument.

## Version History

Introduced in R2012b

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