org.geotools.referencing.operation.projection

Class Krovak

Object

Formattable

AbstractMathTransform

MapProjection

Krovak

All Implemented Interfaces:

Serializable, MathTransform, MathTransform2D

public class Krovak
extends MapProjection

Krovak Oblique Conformal Conic projection (EPSG code 9819). This projection is used in the Czech Republic and Slovakia under the name "Krovak" projection. The geographic coordinates on the ellipsoid are first reduced to conformal coordinates on the conformal (Gaussian) sphere. These spherical coordinates are then projected onto the oblique cone and converted to grid coordinates. The pseudo standard parallel is defined on the conformal sphere after its rotation, to obtain the oblique aspect of the projection. It is then the parallel on this sphere at which the map projection is true to scale; on the ellipsoid it maps as a complex curve.

The compulsory parameters are just the ellipsoid characteristics. All other parameters are optional and have defaults to match the common usage with Krovak projection.

In general the axis of Krovak projection are defined as westing and southing (not easting and northing) and they are also reverted, so if the value of projected coordinates should (and in y, x order in Krovak) be positive the 'Axis' parameter for projection should be defined explicitly like this (in wkt):

PROJCS["S-JTSK (Ferro) / Krovak",
         .
         .
         .
     PROJECTION["Krovak"]
     PARAMETER["semi_major", 6377397.155],
     PARAMETER["semi_minor", 6356078.963],
     UNIT["meter",1.0],
     AXIS["x", WEST],
     AXIS["y", SOUTH]]
     

Axis in Krovak:

   y<------------------+
                       |
    Czech. Rep.        |
                       |
                       x
 

By default, the axis are 'easting, northing' so the values of projected coordinates are negative (and in y, x order in Krovak - it is cold Krovak GIS version).

References:

• Proj-4.4.7 available at www.remotesensing.org/proj
  Relevant files is: PJ_krovak.c
• "Coordinate Conversions and Transformations including Formulas" available at, http://www.remotesensing.org/geotiff/proj_list/guid7.html

Since:

2.4

Author:

Jan Jezek, Martin Desruisseaux

See Also:

Krovak on RemoteSensing.org, Krovak on "Coordinate Conversions and Transformations including Formulas", Krovak on POSC, Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Krovak.NorthProvider
static class	Krovak.Provider

Nested classes/interfaces inherited from class MapProjection

MapProjection.AbstractProvider

Field Summary

Fields

Modifier and Type	Field and Description
protected double	azimuth Azimuth of the centre line passing through the centre of the projection.
protected ParameterDescriptorGroup	descriptors The descriptor group, stored as a field as there are different providers
protected double	pseudoStandardParallel Latitude of pseudo standard parallel.
protected double	x_scale Parameter used by ESRI - scale for X Axis
protected double	xy_plane_rotation Parameter used by ESRI - rotation
protected double	y_scale Parameter used by ESRI - scale for Y Axis

Fields inherited from class MapProjection

centralMeridian, en0, en1, en2, en3, en4, excentricity, excentricitySquared, falseEasting, falseNorthing, globalScale, invertible, isSpherical, latitudeOfOrigin, LOGGER, scaleFactor, semiMajor, semiMinor, SKIP_SANITY_CHECKS

Fields inherited from class Formattable

SINGLE_LINE

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Krovak(ParameterValueGroup parameters, ParameterDescriptorGroup descriptors, boolean esriDefinition) Constructs a new map projection from the supplied parameters.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object object) Compares the specified object with this map projection for equality.
ParameterDescriptorGroup	getParameterDescriptors() Returns the parameter descriptors for this map projection.
ParameterValueGroup	getParameterValues() Returns the parameter values for this map projection.
int	hashCode() Returns a hash value for this projection.
protected Point2D	inverseTransformNormalized(double x, double y, Point2D ptDst) Transforms the specified (x,y) coordinate and stores the result in ptDst.
protected Point2D	transformNormalized(double lambda, double phi, Point2D ptDst) Transforms the specified (λ,φ) coordinates (units in radians) and stores the result in ptDst (linear distance on a unit sphere).

Methods inherited from class MapProjection

checkReciprocal, getSourceDimensions, getTargetDimensions, getToleranceForAssertions, inv_mlfn, inverse, mlfn, orthodromicDistance, resetWarnings, transform, transform, transform

Methods inherited from class AbstractMathTransform

createTransformedShape, derivative, derivative, ensureNonNull, formatWKT, getName, isIdentity, needCopy, normalizeAngle, rollLongitude, transform, transform, transform

Methods inherited from class Formattable

cleanupThreadLocals, toString, toWKT, toWKT, toWKT, toWKT

Methods inherited from class Object

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

Methods inherited from interface MathTransform2D

createTransformedShape, derivative

Methods inherited from interface MathTransform

derivative, isIdentity, toWKT, transform, transform, transform

Field Detail

azimuth

protected final double azimuth

Azimuth of the centre line passing through the centre of the projection. This is equals to the co-latitude of the cone axis at point of intersection with the ellipsoid.

descriptors

protected final ParameterDescriptorGroup descriptors

The descriptor group, stored as a field as there are different providers

x_scale

protected double x_scale

Parameter used by ESRI - scale for X Axis

y_scale

protected double y_scale

Parameter used by ESRI - scale for Y Axis

xy_plane_rotation

protected double xy_plane_rotation

Parameter used by ESRI - rotation

pseudoStandardParallel

protected final double pseudoStandardParallel

Latitude of pseudo standard parallel.

Constructor Detail

Krovak

protected Krovak(ParameterValueGroup parameters,
                 ParameterDescriptorGroup descriptors,
                 boolean esriDefinition)
          throws ParameterNotFoundException

Constructs a new map projection from the supplied parameters.

Parameters:

parameters - The parameter values in standard units.

esriDefinition - true if ESRI parameters are specified.

Throws:

ParameterNotFoundException - if a mandatory parameter is missing.

Method Detail

getParameterDescriptors

public ParameterDescriptorGroup getParameterDescriptors()

Description copied from class: MapProjection

Returns the parameter descriptors for this map projection. This is used for a providing a default implementation of MapProjection.getParameterValues(), as well as arguments checking.

Specified by:

getParameterDescriptors in class MapProjection

Returns:

The parameter descriptors for this math transform, or null.

See Also:

OperationMethod.getParameters()

getParameterValues

public ParameterValueGroup getParameterValues()

Returns the parameter values for this map projection.

Overrides:

getParameterValues in class MapProjection

Returns:

A copy of the parameter values for this map projection.

See Also:

Operation.getParameterValues()

transformNormalized

protected Point2D transformNormalized(double lambda,
                                      double phi,
                                      Point2D ptDst)
                               throws ProjectionException

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

Specified by:

transformNormalized in class MapProjection

Parameters:

lambda - The longitude of the coordinate, in radians.

phi - The latitude of the coordinate, in radians.

ptDst - the specified coordinate point that stores the result of transforming ptSrc, or null. Ordinates will be in a dimensionless unit, as a linear distance on a unit sphere or ellipse.

Returns:

the coordinate point after transforming (lambda, phi) and storing the result in ptDst.

Throws:

ProjectionException - if the point can't be transformed.

inverseTransformNormalized

protected Point2D inverseTransformNormalized(double x,
                                             double y,
                                             Point2D ptDst)
                                      throws ProjectionException

Transforms the specified (x,y) coordinate and stores the result in ptDst.

Specified by:

inverseTransformNormalized in class MapProjection

Parameters:

x - The easting of the coordinate, linear distance on a unit sphere or ellipse.

y - The northing of the coordinate, linear distance on a unit sphere or ellipse.

ptDst - the specified coordinate point that stores the result of transforming ptSrc, or null. Ordinates will be in radians.

Returns:

the coordinate point after transforming x, y and storing the result in ptDst.

Throws:

ProjectionException - if the point can't be transformed.

hashCode

public int hashCode()

Returns a hash value for this projection.

Overrides:

hashCode in class MapProjection

equals

public boolean equals(Object object)

Compares the specified object with this map projection for equality.

Overrides:

equals in class MapProjection

Parameters:

object - The object to compare with this transform.

Returns:

true if the given object is a transform of the same class and if, given identical source position, the transformed position would be the equals.