# gml:secondDefiningParameter

gml:secondDefiningParameter is a property containing the definition of the second parameter that defines the shape of an ellipsoid. An ellipsoid requires two defining parameters: semi-major axis and inverse flattening or semi-major axis and semi-minor axis. When the reference body is a sphere rather than an ellipsoid, only a single defining parameter is required, namely the radius of the sphere; in that case, the semi-major axis "degenerates" into the radius of the sphere. The inverseFlattening element contains the inverse flattening value of the ellipsoid. This value is a scale factor (or ratio). It uses gml:LengthType with the restriction that the unit of measure referenced by the uom attribute must be suitable for a scale factor, such as percent, permil, or parts-per-million. The semiMinorAxis element contains the length of the semi-minor axis of the ellipsoid. When the isSphere element is included, the ellipsoid is degenerate and is actually a sphere. The sphere is completely defined by the semi-major axis, which is the radius of the sphere.

## Element information

Namespace: http://www.opengis.net/gml/3.2

Schema document: external/ogc/gml/3.2.1/datums.xsd

Type: Anonymous

Properties: Global, Qualified

## Content

- gml:SecondDefiningParameter [1..1]

## Attributes

*None*

## Sample instance

<gml:secondDefiningParameter> <gml:SecondDefiningParameter> <gml:inverseFlattening uom="">1.0</gml:inverseFlattening> </gml:SecondDefiningParameter> </gml:secondDefiningParameter>