geodetic2aer

Transform geodetic coordinates to local spherical

Description

example

[az,elev,slantRange] = geodetic2aer(lat,lon,h,lat0,lon0,h0,spheroid) transforms the geodetic coordinates specified by lat, lon, and h to the local azimuth-elevation-range (AER) spherical coordinates specified by az, elev, and slantRange. Specify the origin of the local AER 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.

[az,elev,slantRange] = geodetic2aer(___,angleUnit) specifies the units for latitude, longitude, azimuth, and elevation. Specify angleUnit as 'degrees' (the default) or 'radians'.

Examples

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Find the AER coordinates of the Matterhorn with respect to Zermatt, Switzerland, using the geodetic coordinates of Zermatt and the Matterhorn.

First, specify the reference spheroid as WGS 84. For more information about WGS 84, see Reference Spheroids. The units for ellipsoidal height and slant range 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 Zermatt. Specify h0 as ellipsoidal height in meters.

lat0 = 46.017;
lon0 = 7.750;
h0 = 1673;

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

lat = 45.977;
lon = 7.658;
h = 4531;

Then, calculate the AER coordinates of the Matterhorn with respect to Zermatt. To view the results in standard notation, specify the display format as shortG.

format shortG
[az,elev,slantRange] = geodetic2aer(lat,lon,h,lat0,lon0,h0,wgs84)
az = 
       238.08

elev = 
       18.744

slantRange = 
       8876.8

Reverse the transformation using the aer2geodetic function.

[lat,lon,h] = aer2geodetic(az,elev,slantRange,lat0,lon0,h0,wgs84)
lat = 
       45.977

lon = 
        7.658

h = 
        4531

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.

For more information about reference spheroids, see Reference Spheroids.

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

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

Data Types: char | string

Output Arguments

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Azimuth angles of one or more points in the local AER system, returned as a scalar, vector, matrix, or N-D array. Azimuths are measured clockwise from north. Values are specified in degrees within the half-open interval [0 360). To use values in radians, specify the angleUnit argument as 'radians'.

Elevation angles of one or more points in the local AER system, returned as a scalar, vector, matrix, or N-D array. Elevations are measured with respect to a plane that is perpendicular to the normal of the spheroid surface. If the local origin is on the surface of the spheroid (h0 = 0), then the plane is tangent to the spheroid.

Values are specified in degrees within the closed interval [-90 90]. To use values in radians, specify the angleUnit argument as 'radians'.

Distances from the local origin, returned as a scalar, vector, matrix, or N-D array. Each distance is calculated along a straight, 3-D, Cartesian line. 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'.

Introduced in R2012b