com.luciad.projection

LuciadLightspeedClass TLcdStereographic

java.lang.Object

com.luciad.projection.ALcdProjection

com.luciad.projection.ALcdAzimuthal

com.luciad.projection.TLcdStereographic

All Implemented Interfaces:

ILcdAzimuthal, ILcdProjection, ILcdPropertyChangeSource, Serializable, Cloneable

public class TLcdStereographic
extends ALcdAzimuthal

Stereographic projection.

Introduction

Azimuthal conformal projection with a projection point opposite the origin of the projection.

Properties

• The projection is conformal.
• The central meridian and a particular parallel (if shown) are shown as straight lines.
• All meridians on the polar aspect are projected as straight lines.
• The Equator on the equatorial aspect is projected as a straight line.
• All other meridians and parallels are projected as arcs of circles.
• Directions from the projection origin are true.
• Scale increases away from the projection origin.
• It is not possible to plot the point opposite the projection origin.
• The projection is used for polar maps and miscellaneous special maps.

Example

Sample code

 ILcdProjection projection =
     new TLcdStereographic(20.0, -30.0);
 

Implementation aspects

The equations of the stereographic projection are taken from [Snyder1987].

See Also:

TLcdPolarStereographic, Serialized Form

Field Summary

Fields inherited from class com.luciad.projection.ALcdProjection

fPropertyChangeDispatcher

Fields inherited from interface com.luciad.projection.ILcdProjection

EPSILON

Constructor Summary

Constructors

Constructor and Description
TLcdStereographic() Constructs a stereographic projection with the origin at a point (0.0, 0.0).
TLcdStereographic(double aLongitude, double aLatitude) Constructs a stereographic projection with the origin at a point (aLatitude, aLongitude).
TLcdStereographic(ILcdPoint aOrigin) Constructs a stereographic projection with the origin at an ILcdPoint aOrigin.

Method Summary

Modifier and Type	Method and Description
double[][]	boundaryLats(double aLon) Default implementation.
double[][]	boundaryLons(double aLat) Default implementation.
protected void	calculateCachedValues() Constants based on the point of origin of the projection don't have to be recalculated every time a method is called.
Object	clone() Makes a deep clone of this ILcdProjection.
boolean	inLonLatBounds(ILcdPoint aLLHP) Checks if an ILcdPoint is inside the valid area of geodetic coordinates of the projection.
boolean	inWorldBoundsOnEllipsoid(ILcdPoint aXYPoint, ILcdEllipsoid aEllipsoid) Default implementation calls inWorldBoundsOnSphere with aEllipsoid.getAuxRadius() as sphere radius.
boolean	inWorldBoundsOnSphere(ILcdPoint aXYPoint, double aRadius) Checks if a ILcdPoint is inside the valid cartesian area of the projection.
boolean	isAllInBounds() If all geodetic coordinates (l ,j ) are projected (visible) by an ILcdProjection and all (x,y ) coordinates are bounded this is true.
void	lonlatheight2worldOnEllipsoidSFCT(ILcdPoint aLLHP, ILcdEllipsoid aEllipsoid, ILcd2DEditablePoint aWorldPoint) Default implementation calls lonlatheight2worldOnEllipsoidSFCT with aEllipsoid.getAuxRadius() as sphere radius.
void	lonlatheight2worldOnSphereSFCT(ILcdPoint aLLHP, double aRadius, ILcd2DEditablePoint aWorldPoint) Transforms an ILcd2DEditablePoint on a sphere into the cartesian coordinate system of the projection.
String	toString() Returns the String representation of the stereographic projection.
void	world2DEditableBoundsOnEllipsoidSFCT(ILcdEllipsoid aEllipsoid, ILcd2DEditableBounds aWorldBoundsSFCT) Default implementation calls world2lonlatOnSphereSFCT with aEllipsoid.getAuxRadius() as sphere radius.
void	world2DEditableBoundsOnSphereSFCT(double aRadius, ILcd2DEditableBounds aWorldBound) The projection is cut off because only one hemisphere is projected.
void	world2lonlatOnEllipsoidSFCT(ILcdPoint aXYPoint, ILcdEllipsoid aEllipsoid, ILcd2DEditablePoint aLLPSFCT) Default implementation calls world2lonlatOnSphereSFCT with aEllipsoid.getAuxRadius() as sphere radius.
void	world2lonlatOnSphereSFCT(ILcdPoint aXYPoint, double aRadius, ILcd2DEditablePoint aLLPSFCT) Transforms an ILcdPoint from the cartesian coordinate system of the projection into an ILcd2DEditablePoint onto a sphere.

Methods inherited from class com.luciad.projection.ALcdAzimuthal

equals, getOrigin, getOriginLat, getOriginLon, hashCode, isContinuous, loadProperties, setOriginLat, setOriginLon, writePropertiesSFCT

Methods inherited from class com.luciad.projection.ALcdProjection

addPropertyChangeListener, firePropertyChangeEvent, removePropertyChangeListener

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.luciad.util.ILcdPropertyChangeSource

addPropertyChangeListener, removePropertyChangeListener

Constructor Detail

TLcdStereographic

public TLcdStereographic()

Constructs a stereographic projection with the origin at a point (0.0, 0.0).

TLcdStereographic

public TLcdStereographic(double aLongitude,
                         double aLatitude)

Constructs a stereographic projection with the origin at a point (aLatitude, aLongitude). The central meridian is at the longitude aLongitude.

Parameters:

aLongitude - longitude of the origin of the projection, in decimal degrees.

aLatitude - latitude of the origin of the projection, in decimal degrees.

TLcdStereographic

public TLcdStereographic(ILcdPoint aOrigin)

Constructs a stereographic projection with the origin at an ILcdPoint aOrigin. The central meridian is at aOrigin.getX().

Parameters:

aOrigin - ILcdPoint of the origin of the projection. aOrigin is cloned within the constructor, so no side effects will happen to the projection as a result from changes to aOrigin.

Method Detail

calculateCachedValues

protected void calculateCachedValues()

Description copied from class: ALcdAzimuthal

Constants based on the point of origin of the projection don't have to be recalculated every time a method is called. They only have to be calculated when the projection properties change. Within the methods the pre-calculated values then can be used in order to gain efficiency.

Overrides:

calculateCachedValues in class ALcdAzimuthal

isAllInBounds

public boolean isAllInBounds()

Description copied from interface: ILcdProjection

If all geodetic coordinates (l ,j ) are projected (visible) by an ILcdProjection and all (x,y ) coordinates are bounded this is true. All ILcdProjection objects have bounded (x,y ) coordinates because the projection is cut off if necessary.

Returns:

true if all LonLatPoints are within the bounds of the projection, false otherwise.

lonlatheight2worldOnSphereSFCT

public void lonlatheight2worldOnSphereSFCT(ILcdPoint aLLHP,
                                           double aRadius,
                                           ILcd2DEditablePoint aWorldPoint)
                                    throws TLcdOutOfBoundsException

Description copied from interface: ILcdProjection

Transforms an ILcd2DEditablePoint on a sphere into the cartesian coordinate system of the projection.

Parameters:

aLLHP - point to be projected.

aRadius - radius of the sphere (meters).

aWorldPoint - projected point as side effect.

Throws:

TLcdOutOfBoundsException - If the ILcdPoint aLLHP is not within the valid area of the projection (visible area), then this exception is thrown.

lonlatheight2worldOnEllipsoidSFCT

public void lonlatheight2worldOnEllipsoidSFCT(ILcdPoint aLLHP,
                                              ILcdEllipsoid aEllipsoid,
                                              ILcd2DEditablePoint aWorldPoint)
                                       throws TLcdOutOfBoundsException

Description copied from class: ALcdProjection

Default implementation calls lonlatheight2worldOnEllipsoidSFCT with aEllipsoid.getAuxRadius() as sphere radius.

Specified by:

lonlatheight2worldOnEllipsoidSFCT in interface ILcdProjection

Overrides:

lonlatheight2worldOnEllipsoidSFCT in class ALcdProjection

Parameters:

aLLHP - point to be projected.

aEllipsoid - ellipsoid on which the point is defined.

aWorldPoint - projected point as side effect.

Throws:

TLcdOutOfBoundsException - If the ILcdPoint aLLHP is not within the valid area of the projection (visible area), then this exception is thrown.

world2lonlatOnSphereSFCT

public void world2lonlatOnSphereSFCT(ILcdPoint aXYPoint,
                                     double aRadius,
                                     ILcd2DEditablePoint aLLPSFCT)
                              throws TLcdOutOfBoundsException

Description copied from interface: ILcdProjection

Transforms an ILcdPoint from the cartesian coordinate system of the projection into an ILcd2DEditablePoint onto a sphere.

Parameters:

aXYPoint - projected point for which the corresponding geodetic point is sought.

aRadius - radius of the sphere (meters).

aLLPSFCT - resulting geodetic coordinate as side effect.

Throws:

TLcdOutOfBoundsException - If the ILcdPoint aXYPoint is not within the valid area of the projection (visible area), then this exception is thrown.

world2lonlatOnEllipsoidSFCT

public void world2lonlatOnEllipsoidSFCT(ILcdPoint aXYPoint,
                                        ILcdEllipsoid aEllipsoid,
                                        ILcd2DEditablePoint aLLPSFCT)
                                 throws TLcdOutOfBoundsException

Description copied from class: ALcdProjection

Default implementation calls world2lonlatOnSphereSFCT with aEllipsoid.getAuxRadius() as sphere radius.

Specified by:

world2lonlatOnEllipsoidSFCT in interface ILcdProjection

Overrides:

world2lonlatOnEllipsoidSFCT in class ALcdProjection

Parameters:

aXYPoint - projected point for which the corresponding geodetic point is sought.

aEllipsoid - ellipsoid on which the geodetic coordinate is defined.

aLLPSFCT - resulting geodetic coordinate as side effect.

Throws:

TLcdOutOfBoundsException - If the ILcdPoint aXYPoint is not within the valid area of the projection (visible area), then this exception is thrown.

inLonLatBounds

public boolean inLonLatBounds(ILcdPoint aLLHP)

Description copied from interface: ILcdProjection

Checks if an ILcdPoint is inside the valid area of geodetic coordinates of the projection. The valid area is determined by the LonLatPoints that are visible and for which the corresponding cartesian coordinate is within the boundaries.

Parameters:

aLLHP - ILcdPoint to be checked upon.

Returns:

true if valid, false if invalid.

boundaryLons

public double[][] boundaryLons(double aLat)

Description copied from class: ALcdProjection

Default implementation. To be redefined for specific projections.

Specified by:

boundaryLons in interface ILcdProjection

Overrides:

boundaryLons in class ALcdProjection

Parameters:

aLat - latitude in decimal degrees and -90.0 <= aLat<= 90.0.

Returns:

the array of pairs of longitudes[0] and longitudes[1], where the closed interval longitudes[0] -> longitudes[1] is in visible area and -180.0 <= lon[i] <= 180.0.

boundaryLats

public double[][] boundaryLats(double aLon)

Description copied from class: ALcdProjection

Default implementation. To be redefined for specific projections.

Specified by:

boundaryLats in interface ILcdProjection

Overrides:

boundaryLats in class ALcdProjection

Parameters:

aLon - longitude in decimal degrees -180.0 <= lon <= 180.0 .

Returns:

the array of pairs of latitudes lats[0] and lats[1], where the closed interval lats[0] -> lats[1] is in visible area and -90.0 <= lats[i] <= 90.0 .

world2DEditableBoundsOnSphereSFCT

public void world2DEditableBoundsOnSphereSFCT(double aRadius,
                                              ILcd2DEditableBounds aWorldBound)

The projection is cut off because only one hemisphere is projected.

Parameters:

aRadius - radius of the sphere.

aWorldBound - the bounds of the projection in world coordinates as side effect.

inWorldBoundsOnSphere

public boolean inWorldBoundsOnSphere(ILcdPoint aXYPoint,
                                     double aRadius)

Description copied from interface: ILcdProjection

Checks if a ILcdPoint is inside the valid cartesian area of the projection. The valid cartesian area is determined naturally by the projection bounds or by an artificial introduced boundary limit because some cartesian points are at infinity. The shape of the valid cartesian area is in many cases rectangular or circular although it might be more complex.

Parameters:

aXYPoint - point to be checked upon.

aRadius - radius of the sphere.

Returns:

true if valid, false if invalid.

inWorldBoundsOnEllipsoid

public boolean inWorldBoundsOnEllipsoid(ILcdPoint aXYPoint,
                                        ILcdEllipsoid aEllipsoid)

Description copied from class: ALcdProjection

Default implementation calls inWorldBoundsOnSphere with aEllipsoid.getAuxRadius() as sphere radius.

Specified by:

inWorldBoundsOnEllipsoid in interface ILcdProjection

Overrides:

inWorldBoundsOnEllipsoid in class ALcdProjection

Parameters:

aXYPoint - point to be checked upon.

aEllipsoid - ellipsoid on which the geodetic coordinate is defined.

Returns:

true if valid, false if invalid.

See Also:

ILcdProjection.inWorldBoundsOnSphere(com.luciad.shape.ILcdPoint, double)

world2DEditableBoundsOnEllipsoidSFCT

public void world2DEditableBoundsOnEllipsoidSFCT(ILcdEllipsoid aEllipsoid,
                                                 ILcd2DEditableBounds aWorldBoundsSFCT)

Description copied from class: ALcdProjection

Default implementation calls world2lonlatOnSphereSFCT with aEllipsoid.getAuxRadius() as sphere radius.

Specified by:

world2DEditableBoundsOnEllipsoidSFCT in interface ILcdProjection

Overrides:

world2DEditableBoundsOnEllipsoidSFCT in class ALcdProjection

Parameters:

aEllipsoid - ellipsoid considered.

aWorldBoundsSFCT - the bounds of the projection in world coordinates as side effect.

toString

public String toString()

Returns the String representation of the stereographic projection.

Specified by:

toString in interface ILcdProjection

Overrides:

toString in class Object

Returns:

the String representation of the stereographic projection.

clone

public Object clone()

Description copied from interface: ILcdProjection

Makes a deep clone of this ILcdProjection.

Specified by:

clone in interface ILcdProjection

Overrides:

clone in class ALcdAzimuthal

Returns:

deep clone of this ILcdProjection.