referenceEllipsoid
Reference ellipsoid
Description
A referenceEllipsoid
object encapsulates a reference
ellipsoid, modeled as an oblate spheroid with three additional properties: name, unit of
length of the semi-major and semi-minor axes, and a numerical EPSG code.
Creation
There are several ways to create reference ellipsoid objects, including:
Create a
geocrs
object, and then query itsSpheroid
property.Create a
projcrs
object, access thegeocrs
object contained in itsGeographicCRS
property, and then query theSpheroid
property of thegeocrs
.Create a reference ellipsoid for the World Geodetic System of 1984 (WGS84) by using the
wgs84Ellipsoid
function.Use the
referenceEllipsoid
function (described here).
Syntax
Description
E = referenceEllipsoid
creates a
referenceEllipsoid
object that represents the unit
sphere.
E = referenceEllipsoid(
creates
a name
)referenceEllipsoid
object corresponding to
name
. name
is case-insensitive.
The values of the SemimajorAxis
and
SemiminorAxis
properties are in meters.
E = referenceEllipsoid(
creates
a code
)referenceEllipsoid
object corresponding to the numerical
EPSG code, code
. The unit of length used for the
SemimajorAxis
and SemiminorAxis
properties depends on the ellipsoid selected, and is indicated in the property
LengthUnit
.
E = referenceEllipsoid(
andname
,lengthUnit
)
E = referenceEllipsoid(
create a code
,lengthUnit
)referenceEllipsoid
object with the
SemimajorAxis
and SemiminorAxis
properties in the specified unit of length, LengthUnit
. The
unit of length can be any length unit supported by the validateLengthUnit
function.
Input Arguments
Properties
Examples
More About
Tips
When you define an ellipsoid in terms of semimajor and semiminor axes (rather than semimajor axis and inverse flattening, or semimajor axis and eccentricity), a small loss of precision in the last few digits of
Flattening
,Eccentricity
, andThirdFlattening
may occur. This is unavoidable, but does not affect the results of practical computation.
Version History
Introduced in R2012aSee Also
oblateSpheroid
| referenceSphere
| validateLengthUnit
| wgs84Ellipsoid
| geocrs