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# geodetic2ecef

Transform geodetic to geocentric (ECEF) coordinates

## Syntax

``````[X,Y,z] = geodetic2ecef(spheroid,lat,lon,h)``````
``````[X,Y,Z] = geodetic2ecef(___,angleUnit)``````
``[X,Y,Z] = geodetic2ecef(lat,lon,h,spheroid)``

## Description

example

``````[X,Y,z] = geodetic2ecef(spheroid,lat,lon,h)``` transforms geodetic point locations specified by the geodetic coordinate arrays `lat` (geodetic latitude), `lon` (longitude), and `h` (ellipsoidal height) to geocentric Earth-Centered Earth-Fixed (ECEF) Cartesian coordinates `x`, `y`, and `z`. The geodetic coordinates refer to the reference body specified by the spheroid object, `spheroid`. ```
``````[X,Y,Z] = geodetic2ecef(___,angleUnit)``` where `angleUnit` specifies the units of the latitude and longitude coordinates, either `'degrees'` or `'radians'`.```
````[X,Y,Z] = geodetic2ecef(lat,lon,h,spheroid)` This syntax is supported but not recommended. `lat` and `lon` must be in radians. `spheroid` can be either a spheroid or an ellipsoid vector of the form: `[semimajor_axis, eccentricity]`. In this case, `h` must use the same units as the semimajor axis. `X`, `Y`, and `Z` will be expressed in these units also.```

## Examples

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Convert the geodetic coordinates for Paris, France (48 degrees 51 minutes 24 seconds North, 2 degrees 21 minutes 03 seconds East) to geocentric Earth-Centered Earth-Fixed (ECEF) Cartesian coordinates.

`lat = dms2degrees([48 51 24])`
```lat = 48.8567 ```
`lon = dms2degrees([2 21 03])`
```lon = 2.3508 ```
```h = 80; wgs84 = wgs84Ellipsoid('meters'); [x,y,z] = geodetic2ecef(wgs84,lat,lon,h)```
```x = 4.2010e+06 ```
```y = 1.7246e+05 ```
```z = 4.7801e+06 ```

## Input Arguments

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Reference spheroid, specified as a `referenceEllipsoid`, `oblateSpheroid`, or `referenceSphere` object. To create a spheroid object, use the creation function specific to the object, or the `wgs84Ellipsoid` function.

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

Geodetic latitudes of one or more points, specified as a scalar value, vector, matrix, or N-D array. Values must be in units that match the input argument `angleUnit`, if supplied, and in degrees, otherwise.

Data Types: `single` | `double`

Longitudes of one or more points, specified as a scalar value, vector, matrix, or N-D array. Values must be in units that match the input argument `angleUnit`, if supplied, and in degrees, otherwise.

Data Types: `single` | `double`

Ellipsoidal height, specified as a scalar. `h` must be expressed in the same length unit as the `spheroid`.

Data Types: `single` | `double` | `int8` | `int16` | `int32` | `int64` | `uint8` | `uint16` | `uint32` | `uint64`

Units of angles, specified as ‘degrees' (default), or 'radians'.

Data Types: `char`

## Output Arguments

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x-coordinates of one or more points in the spheroid-centric ECEF system, returned as a scalar value, vector, matrix, or N-D array. Units are determined by the `LengthUnit` property of the `spheroid` object.

y-coordinates of one or more points in the spheroid-centric ECEF system, returned as a scalar value, vector, matrix, or N-D array. Units are determined by the `LengthUnit` property of the `spheroid` object.

z-coordinates of one or more points in the spheroid-centric ECEF system, returned as a scalar value, vector, matrix, or N-D array. Units are determined by the `LengthUnit` property of the `spheroid` object.

## Tips

• The geocentric Cartesian (ECEF) coordinate system is fixed with respect to the Earth, with its origin at the center of the spheroid and its positive X-, Y-, and Z axes intersecting the surface at the following points:

LatitudeLongitude Notes
X-axis00Equator at the Prime Meridian
Y-axis090Equator at 90-degrees East
Z-zxis900North Pole