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java.lang.Object org.geotools.ct.AbstractMathTransform org.geotools.ct.proj.MapProjection org.geotools.ct.proj.PlanarProjection org.geotools.ct.proj.Stereographic
Stereographic
.
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:
"Oblique_Stereographic"
(EPSG code 9809), alias "Double Stereographic"
in ESRI software"Stereographic"
in ESRI software (NOT EPSG code 9809)"Polar_Stereographic"
(EPSG code 9810, uses iteration for the inverse)"Polar_Stereographic_Series"
(EPSG code 9810), uses a series for the inverse.
This is a little bit faster, but may be a little bit less accurate)"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.
"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.
"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.
"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.
"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.
"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"
.
"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:
"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 
IDENTITY 
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
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)
getName
in class MapProjection


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