org.geotools.referencing.operation.projection

Class IdrKrovak

java.lang.Object

MapProjection

org.geotools.referencing.operation.projection.IdrKrovak

public class IdrKrovak
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 (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

See Also:

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

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	IdrKrovak.Provider The org.geotools.referencing.operation.MathTransformProvider for an krovak projection.

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 double	pseudoStandardParallel Latitude of pseudo standard parallel.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	IdrKrovak(ParameterValueGroup parameters) 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()
ParameterValueGroup	getParameterValues()
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 java.lang.Object

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

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.

pseudoStandardParallel

protected final double pseudoStandardParallel

Latitude of pseudo standard parallel.

Constructor Detail

IdrKrovak

protected IdrKrovak(ParameterValueGroup parameters)
             throws ParameterNotFoundException

Constructs a new map projection from the supplied parameters.

Parameters:

parameters - The parameter values in standard units.

Throws:

ParameterNotFoundException - if a mandatory parameter is missing.

Method Detail

getParameterDescriptors

public ParameterDescriptorGroup getParameterDescriptors()

getParameterValues

public ParameterValueGroup 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).

Throws:

ProjectionException

inverseTransformNormalized

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

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

Throws:

ProjectionException

hashCode

public int hashCode()

Returns a hash value for this projection.

equals

public boolean equals(Object object)

Compares the specified object with this map projection for equality.