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lla2ned

Transform geodetic coordinates to local north-east-down coordinates

Since R2021a

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    Syntax

    xyzNED = lla2ned(lla,lla0,method)

    Description

    xyzNED = lla2ned(lla,lla0,method) transforms the geodetic coordinates lla to local north-east-down (NED) Cartesian coordinates xyzNED. Specify the origin of the local NED system as the geodetic coordinates lla0.

    Note

    • The latitude and longitude values in the geodetic coordinate system use the World Geodetic System of 1984 (WGS84) standard.

    • Specify altitude as height in meters above the WGS84 reference ellipsoid.

    example

    Examples

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    Open Live Script

    Specify the geodetic coordinates of the local origin in Zermatt, Switzerland.

    lla0 = [46.017 7.750 1673]; % [lat0 lon0 alt0]

    Specify the geodetic coordinates of a point of interest. In this case, the point of interest is the Matterhorn.

    lla = [45.976 7.658 4531]; % [lat lon alt]

    Transform the geodetic coordinates to local NED coordinates using flat earth approximation.

    xyzNED = lla2ned(lla,lla0,'flat')
    xyzNED = 1×3
103 ×

   -4.5572   -7.1244   -2.8580

    Input Arguments

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    Geodetic coordinates, specified as a three-element row vector or an n-by-3 matrix. n is the number of points to transform. Specify each point in the form [lat lon alt]. lat and lon specify the latitude and longitude respectively in degrees. alt specifies the altitude in meters.

    Example: [45.976 7.658 4531]

    Data Types: double

    Origin of the local NED system with the geodetic coordinates, specified as a three-element row vector or an n-by-3 matrix. n is the number of origin points. Specify each point in the form [lat0 lon0 alt0]. lat0 and lon0 specify the latitude and longitude respectively in degrees. alt0 specifies the altitude in meters.

    Example: [46.017 7.750 1673]

    Data Types: double

    Transformation method, specified as 'flat' or 'ellipsoid'. This argument specifies whether the function assumes the planet is flat or ellipsoidal.

    The flat Earth transformation method has these limitations:

    • Assumes that the flight path and bank angle are zero.

    • Assumes that the flat Earth z-axis is normal to the Earth at only the initial geodetic latitude and longitude. This method has higher accuracy over small distances from the initial geodetic latitude and longitude, and closer to the equator. The method calculates a longitude with higher accuracy when the variation in latitude is smaller.

    • Latitude values of +90 and -90 degree may return unexpected values because of singularity at the poles.

    Data Types: char | string

    Output Arguments

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    Local NED Cartesian coordinates, returned as a three-element row vector or an n-by-3 matrix. n is the number of transformed points. Each point is in the form [xNorth yEast zDown]. xNorth, yEast, and zDown are the respective x-, y-, and z-coordinates, in meters, of the point in the local NED system.

    Data Types: double

    Extended Capabilities

    C/C++ Code Generation
    Generate C and C++ code using MATLAB® Coder™.

    Version History

    Introduced in R2021a

    See Also

    Functions