Class Stereographic

  extended byorg.geotools.ct.AbstractMathTransform
      extended byorg.geotools.ct.proj.MapProjection
          extended byorg.geotools.ct.proj.PlanarProjection
              extended byorg.geotools.ct.proj.Stereographic
All Implemented Interfaces:
MathTransform, MathTransform2D,
Direct Known Subclasses:
ObliqueStereographic, PolarStereographic

Deprecated. Replaced by Stereographic.

public abstract class Stereographic
extends PlanarProjection

Stereographic Projection. The directions starting from the central point are true, but the areas and the lengths become increasingly deformed as one moves away from the center. This projection is used to represent polar areas. It can be adapted for other areas having a circular form.

This implementation, and its subclasses, provides transforms for four cases of the stereographic projection:

Both the "Oblique_Stereographic" and "Stereographic" projections are "double" projections involving two parts: 1) a conformal transformation of the geographic coordinates to a sphere and 2) a spherical Stereographic projection. The EPSG considers both methods to be valid, but considers them to be a different coordinate operation method.

The "Stereographic" case uses the USGS equations of Snyder. This uses a simplified conversion to the conformal sphere that computes the conformal latitude of each point on the sphere.

The "Oblique_Stereographic" case uses equations from the EPSG. This uses a more generalized form of the conversion to the conformal sphere; using only a single conformal sphere at the origin point. Since this is a "double" projection, it is sometimes called the "Double Stereographic". The "Oblique_Stereographic" is used in New Brunswick (Canada) and the Netherlands.

The "Stereographic" and "Double Stereographic" names are used in ESRI's ArcGIS 8.x product. The "Oblique_Stereographic" name is the EPSG name for the later only.

WARNING: Tests points calculated with ArcGIS's "Double Stereographic" are not always equal to points calculated with the "Oblique_Stereographic". However, where there are differences, two different implementations of these equations (EPSG guidence note 7 and libproj) calculate the same values. Until these differences are resolved, please be careful when using this projection.

If a "latitude_of_origin" parameter is supplied and is not consistent with the projection classification (for example a latitude different from ±90? for the polar case), then the oblique or polar case will be automatically inferred from the latitude. In other words, the latitude of origin has precedence on the projection classification. If ommited, then the default value is 90?N for "Polar_Stereographic" and 0? for "Oblique_Stereographic".

The "latitude_true_scale" parameter is not specified by the EPSG and is only used for the "Polar_Stereographic" case. The "Polar_Stereographic_Series" does not include this parameter. References:

$Id: 17672 2006-01-19 00:25:55Z desruisseaux $
Andr? Gosselin, Martin Desruisseaux, Rueben Schulz
See Also:
Stereographic projection on MathWorld, Polar_Stereographic, Oblique_Stereographic, Stereographic, Some Random Stereographic Issues, Serialized Form
TODO: Declares that "Stereographic" is an ESRI name. Add the "Double Stereographic" alias (from ESRI) for "Oblique_Stereographic".

Field Summary
Fields inherited from class org.geotools.ct.proj.MapProjection
centralMeridian, e, es, falseEasting, falseNorthing, globalScale, isSpherical, latitudeOfOrigin, scaleFactor, semiMajor, semiMinor
Fields inherited from interface org.geotools.ct.MathTransform2D
Constructor Summary
protected Stereographic(Projection parameters)
          Deprecated. Construct a stereographic transformation from the specified parameters.
Method Summary
 java.lang.String getName(java.util.Locale locale)
          Deprecated. Returns a human readable name localized for the specified locale.
Methods inherited from class org.geotools.ct.proj.MapProjection
equals, getDimSource, getDimTarget, hashCode, inverse, inverseTransformNormalized, toString, transform, transform, transform, transformNormalized
Methods inherited from class org.geotools.ct.AbstractMathTransform
createTransformedShape, derivative, derivative, fromGeoAPI, isIdentity, transform
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Methods inherited from interface org.geotools.ct.MathTransform2D
createTransformedShape, derivative
Methods inherited from interface org.geotools.ct.MathTransform
derivative, isIdentity, transform

Constructor Detail


protected Stereographic(Projection parameters)
                 throws MissingParameterException
Construct a stereographic transformation from the specified parameters.

parameters - The parameter values in standard units.
MissingParameterException - if a mandatory parameter is missing.
Method Detail


public java.lang.String getName(java.util.Locale locale)
Returns a human readable name localized for the specified locale.

Specified by:
getName in class MapProjection

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