map.geodesy.AuthalicLatitudeConverter

Convert between geodetic and authalic latitudes

Description

An AuthalicLatitudeConverter object provides conversion methods between geodetic and authalic latitudes for an ellipsoid with a given eccentricity.

The authalic latitude maps an ellipsoid (oblate spheroid) to a sphere while preserving surface area. Use authalic latitudes when implementing equal area map projections on the ellipsoid.

Creation

Syntax

converter = map.geodesy.AuthalicLatitudeConverter
converter = map.geodesy.AuthalicLatitudeConverter(spheroid)

Description

example

converter = map.geodesy.AuthalicLatitudeConverter creates an AuthalicLatitudeConverter object for a sphere and sets the Eccentricity to 0.

example

converter = map.geodesy.AuthalicLatitudeConverter(spheroid) creates an authalic latitude converter object and sets the Eccentricity property to match the specified spheroid object.

Input Arguments

expand all

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');

Properties

expand all

Ellipsoid eccentricity, specified as a numeric scalar. Eccentricity is in the interval [0, 0.5]. Eccentricities larger than 0.5 are possible in theory, but do not occur in practice and are not supported.

Data Types: double

Object Functions

forward Convert geodetic latitude to authalic, conformal, isometric, or rectifying latitude
inverse Convert authalic, conformal, isometric, or rectifying latitude to geodetic latitude

Examples

collapse all

Create a Geodetic Reference System 1980 (grs80) reference ellipsoid.

grs80 = referenceEllipsoid('GRS 80');

Create an authalic converter object and set the value of the Eccentricity property.

conv1 = map.geodesy.AuthalicLatitudeConverter;
conv1.Eccentricity = grs80.Eccentricity
conv1 = 

  AuthalicLatitudeConverter with properties:

    Eccentricity: 0.0818

Create a reference ellipsoid.

grs80 = referenceEllipsoid('GRS 80');

Create an authalic latitude converter object based on the ellipsoid.

conv2 = map.geodesy.AuthalicLatitudeConverter(grs80)
conv1 = 

  AuthalicLatitudeConverter with properties:

    Eccentricity: 0.0818

Introduced in R2013a