# geodetic2ned

Transform geodetic coordinates to local north-east-down

## Syntax

``````[xNorth,yEast,zDown] = geodetic2ned(lat,lon,h,lat0,lon0,h0,spheroid)``````
``[___] = geodetic2ned(___,angleUnit)``

## Description

example

``````[xNorth,yEast,zDown] = geodetic2ned(lat,lon,h,lat0,lon0,h0,spheroid)``` transforms the geodetic coordinates specified by `lat`, `lon`, and `h` to the local north-east-down (NED) Cartesian coordinates specified by `xNorth`, `yEast`, and `zDown`. Specify the origin of the local NED system with the geodetic coordinates `lat0`, `lon0`, and `h0`. Each coordinate input argument must match the others in size or be scalar. Specify `spheroid` as the reference spheroid for the geodetic coordinates.```
````[___] = geodetic2ned(___,angleUnit)` specifies the units for latitude and longitude. Specify `angleUnit` as `'degrees'` (the default) or `'radians'`.```

## Examples

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Find the NED coordinates of Mount Mansfield with respect to a nearby aircraft, using their geodetic coordinates.

First, specify the reference spheroid as WGS 84. For more information about WGS 84, see Comparison of Reference Spheroids. The units for the ellipsoidal height and NED coordinates must match the units specified by the `LengthUnit` property of the reference spheroid. The default length unit for the reference spheroid created by `wgs84Ellipsoid` is `'meter'`.

`wgs84 = wgs84Ellipsoid;`

Specify the geodetic coordinates of the local origin. In this example, the local origin is the aircraft. Specify `h0` as ellipsoidal height in meters.

```lat0 = 44.532; lon0 = -72.782; h0 = 1699;```

Specify the geodetic coordinates of the point of interest. In this example, the point of interest is Mount Mansfield. Specify `h` as ellipsoidal height in meters.

```lat = 44.544; lon = -72.814; h = 1340;```

Then, calculate the NED coordinates of Mount Mansfield with respect to the aircraft. Since the ellipsoidal height of the aircraft is greater than the height of Mount Mansfield, a passenger needs to look down to see the mountaintop. The z-axis of an NED coordinate system points down. Thus, the value of `zDown` is positive. View the results in standard notation by specifying the display format as `shortG`.

```format shortG [xNorth,yEast,zDown] = geodetic2ned(lat,lon,h,lat0,lon0,h0,wgs84)```
```xNorth = 1334.3 ```
```yEast = -2543.6 ```
```zDown = 359.65 ```

Reverse the transformation using the `ned2geodetic` function.

`[lat,lon,h] = ned2geodetic(xNorth,yEast,zDown,lat0,lon0,h0,wgs84)`
```lat = 44.544 ```
```lon = -72.814 ```
```h = 1340 ```

## Input Arguments

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Geodetic latitude of one or more points, specified as a scalar, vector, matrix, or N-D array. Specify the values in degrees. To use values in radians, specify the `angleUnit` argument as `'radians'`.

Data Types: `single` | `double`

Geodetic longitude of one or more points, specified as a scalar, vector, matrix, or N-D array. Specify the values in degrees. To use values in radians, specify the `angleUnit` argument as `'radians'`.

Data Types: `single` | `double`

Ellipsoidal height of one or more points, specified as a scalar, vector, matrix, or N-D array. Specify values in units that match the `LengthUnit` property of the `spheroid` object. For example, the default length unit for the reference ellipsoid created by `wgs84Ellipsoid` is `'meter'`.

Data Types: `single` | `double`

Geodetic latitude of the local origin, specified as a scalar, vector, matrix, or N-D array. The local origin can refer to one point or a series of points (for example, a moving platform). Specify the values in degrees. To use values in radians, specify the `angleUnit` argument as `'radians'`.

Data Types: `single` | `double`

Geodetic longitude of the local origin, specified as a scalar, vector, matrix, or N-D array. The local origin can refer to one point or a series of points (for example, a moving platform). Specify the values in degrees. To use values in radians, specify the `angleUnit` argument as `'radians'`.

Data Types: `single` | `double`

Ellipsoidal height of the local origin, specified as a scalar, vector, matrix, or N-D array. The local origin can refer to one point or a series of points (for example, a moving platform). Specify values in units that match the `LengthUnit` property of the `spheroid` object. For example, the default length unit for the reference ellipsoid created by `wgs84Ellipsoid` is `'meter'`.

Data Types: `single` | `double`

Reference spheroid, specified as a `referenceEllipsoid` object, `oblateSpheroid` object, or `referenceSphere` object. The term reference spheroid is used synonymously with reference ellipsoid. To create a reference spheroid, use the creation function for the object. To specify the reference ellipsoid for WGS84, use the `wgs84Ellipsoid` function.

Example: `spheroid = referenceEllipsoid('GRS 80');`

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. Units are specified by the `LengthUnit` property of the `spheroid` argument. For example, the default length unit for the reference ellipsoid created by `wgs84Ellipsoid` is `'meter'`.

NED y-coordinates of one or more points in the local NED system, returned as a scalar, vector, matrix, or N-D array. Units are specified by the `LengthUnit` property of the `spheroid` argument. For example, the default length unit for the reference ellipsoid created by `wgs84Ellipsoid` is `'meter'`.

NED z-coordinates of one or more points in the local NED system, returned as a scalar, vector, matrix, or N-D array. Units are specified by the `LengthUnit` property of the `spheroid` argument. For example, the default length unit for the reference ellipsoid created by `wgs84Ellipsoid` is `'meter'`.

## Version History

Introduced in R2012b

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