Convert from geocentric latitude to radius of ellipsoid planet

Since R2021b

## Syntax

``r = geocradius(lambda)``
``r = geocradius(lambda,model)``
``r = geocradius(lambda,f,Re)``

## Description

### WGS84 Ellipsoid Planet

example

````r = geocradius(lambda)` estimates the radius, `r`, of an ellipsoid planet at a particular geocentric latitude, `lambda`.`r = geocradius(lambda,model)` estimates the radius for a specific ellipsoid planet. ```

### Custom Ellipsoid Planet

example

````r = geocradius(lambda,f,Re)` is another alternate method for estimating the radius for a custom ellipsoid planet defined by flattening, `f`, and the equatorial radius, `Re`, in meters.```

## Examples

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Determine radius at 45 degrees latitude.

```r = geocradius(45) ```
```r = 6.3674e+006```

Determine radius at multiple latitudes.

`r = geocradius([0 45 90])`
```r = 1.0e+006 * 6.3781 6.3674 6.3568```

Determine radius at multiple latitudes, specifying WGS84 ellipsoid model.

`r = geocradius([0 45 90], 'WGS84')`
```r = 1.0e+006 * 6.3781 6.3674 6.3568```

Determine radius at multiple latitudes, specifying custom ellipsoid model.

```f = 1/196.877360; Re = 3397000; r = geocradius([0 45 90], f, Re)```
```r = 1.0e+006 * 3.3970 3.3883 3.3797```

## Input Arguments

collapse all

Geocentric latitude, specified as a double, in degrees.

Data Types: `double`

Ellipsoid planet model, specified as `'WGS84'`.

Data Types: `double`

Flattening at each pole, specified as a scalar.

Data Types: `double`

Equatorial radius, specified as a scalar in meters.

Data Types: `double`

## Output Arguments

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Radius of an ellipsoid planet, returned as a double, in meters.

## References

[1] Stevens, Brian L., Frank L. Lewis, Aircraft Control and Simulation, John Wiley & Sons, New York, NY, 1992.

[2] Zipfel, Peter H., and D. E. Penny, Modeling and Simulation of Aerospace Vehicle Dynamics. Second Edition. Reston, VA: AIAA Education Series, 2000.

## Version History

Introduced in R2021b