org.geotoolkit.referencing.operation.projection
Class ObliqueStereographic

Object
  FormattableObject
      AbstractMathTransform
          AbstractMathTransform2D
              UnitaryProjection
                  Stereographic
                      ObliqueStereographic

All Implemented Interfaces:

Serializable, Formattable, Parameterized, LenientComparable, MathTransform, MathTransform2D

@Immutable
public class ObliqueStereographic
extends Stereographic

Oblique Stereographic projection (EPSG code 9809). The formulas used below are not from the EPSG, but rather those of the "Oblique Stereographic Alternative" in the libproj4 package written by Gerald Evenden. His work is acknowledged here and greatly appreciated.

The forward equations used in libproj4 are the same as those given in the UNB reports for the Double Stereographic. The inverse equations are similar, but use different methods to iterate for the latitude.

References

• libproj4 is available at libproj4 Miscellanea.
  Relevant files are: PJ_sterea.c, pj_gauss.c, pj_fwd.c, pj_inv.c and lib_proj.h
• Gerald Evenden. "Supplementary PROJ.4 Notes - Oblique Stereographic Alternative".
• "Coordinate Conversions and Transformations including Formulas",
  EPSG Guidance Note Number 7, Version 19.
• Krakiwsky, E.J., D.B. Thomson, and R.R. Steeves. 1977.
  A Manual for Geodetic Coordinate Transformations in the Maritimes.
  Geodesy and Geomatics Engineering, UNB. Technical Report No. 48.
• Thomson, D.B., M.P. Mepham and R.R. Steeves. 1977.
  The Stereographic Double Projection.
  Surveying Engineering, University of New Brunswick. Technical Report No. 46.

Since:

2.4

Version:

3.19

Author:

Gerald Evenden (USGS), Rueben Schulz (UBC), Martin Desruisseaux (Geomatys), Rémi Maréchal (Geomatys)

See Also:

PolarStereographic, EquatorialStereographic, Serialized Form

Module:

referencing/geotk-referencing (download)

View source code for this class

Nested Class Summary

Nested classes/interfaces inherited from class UnitaryProjection

UnitaryProjection.Parameters

Field Summary

Fields inherited from class UnitaryProjection

excentricity, excentricitySquared

Fields inherited from class FormattableObject

EPSG, GEOTIFF, INTERNAL, OGC, SINGLE_LINE

Constructor Summary

protected

ObliqueStereographic(UnitaryProjection.Parameters parameters) Constructs an oblique stereographic projection (EPSG equations).

Method Summary

Matrix	derivative(Point2D point) Gets the derivative of this transform at a point.
protected void	inverseTransform(double[] srcPts, int srcOff, double[] dstPts, int dstOff) Transforms the specified (x,y) coordinates and stores the result in dstPts (angles in radians).
protected void	transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff) Transforms the specified (λ,φ) coordinates (units in radians) and stores the result in dstPts (linear distance on a unit sphere).

Methods inherited from class Stereographic

create, equals

Methods inherited from class UnitaryProjection

computeHashCode, finish, getParameterValues, getUnmarshalledParameters, inverse, resetWarnings, rollLongitude, transform, unrollLongitude

Methods inherited from class AbstractMathTransform2D

getParameterDescriptors, getSourceDimensions, getTargetDimensions, transform

Methods inherited from class AbstractMathTransform

createTransformedShape, derivative, ensureNonNull, equals, formatWKT, getName, hashCode, isIdentity, rollLongitude, transform, transform, transform, transform

Methods inherited from class FormattableObject

getDefaultIndentation, print, setDefaultIndentation, toString, toWKT, toWKT, toWKT

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface MathTransform2D

createTransformedShape

Methods inherited from interface MathTransform

derivative, isIdentity, toWKT, transform, transform, transform, transform

Constructor Detail

ObliqueStereographic

protected ObliqueStereographic(UnitaryProjection.Parameters parameters)

Constructs an oblique stereographic projection (EPSG equations).

Parameters:

parameters - The parameters of the projection to be created.

Method Detail

transform

protected void transform(double[] srcPts,
                         int srcOff,
                         double[] dstPts,
                         int dstOff)
                  throws ProjectionException

Transforms the specified (λ,φ) coordinates (units in radians) and stores the result in dstPts (linear distance on a unit sphere).

Overrides:

transform in class Stereographic

Parameters:

srcPts - The array containing the source point coordinate, as (longitude, latitude) angles in radians.

srcOff - The offset of the point to be converted in the source array.

dstPts - the array into which the converted point coordinate is returned (may be the same than srcPts). Ordinates will be in a dimensionless unit, as a linear distance on a unit sphere or ellipse.

dstOff - The offset of the location of the converted point that is stored in the destination array.

Throws:

ProjectionException - if the point can't be converted.

inverseTransform

protected void inverseTransform(double[] srcPts,
                                int srcOff,
                                double[] dstPts,
                                int dstOff)
                         throws ProjectionException

Transforms the specified (x,y) coordinates and stores the result in dstPts (angles in radians).

Overrides:

inverseTransform in class Stereographic

Parameters:

srcPts - The array containing the source point coordinate, as linear distance on a unit sphere or ellipse.

srcOff - The offset of the point to be converted in the source array.

dstPts - the array into which the converted point coordinate is returned (may be the same than srcPts). Ordinates will be (longitude, latitude) angles in radians.

dstOff - The offset of the location of the converted point that is stored in the destination array.

Throws:

ProjectionException - if the point can't be converted.

derivative

public Matrix derivative(Point2D point)
                  throws ProjectionException

Gets the derivative of this transform at a point.

Specified by:

derivative in interface MathTransform2D

Overrides:

derivative in class Stereographic

Parameters:

point - The coordinate point where to evaluate the derivative.

Returns:

The derivative at the specified point as a 2×2 matrix.

Throws:

ProjectionException - if the derivative can't be evaluated at the specified point.

See Also:

MathTransform2D.derivative(Point2D)