ucar.unidata.geoloc.projection

Class Stereographic

java.lang.Object

ucar.unidata.geoloc.projection.AbstractProjection

ucar.unidata.geoloc.projection.Stereographic

All Implemented Interfaces:

Projection

@Immutable
public class Stereographic
extends AbstractProjection

Stereographic projection, spherical earth. Projection plane is a plane tangent to the earth at latt, lont. see John Snyder, Map Projections used by the USGS, Bulletin 1532, 2nd edition (1983), p 153

Field Summary

Fields inherited from class ucar.unidata.geoloc.projection.AbstractProjection

atts, EARTH_RADIUS, INDEX_LAT, INDEX_LON, INDEX_X, INDEX_Y, isLatLon, name, PI, PI_OVER_2, PI_OVER_4, TOLERANCE

Constructor Summary

Constructors

Constructor and Description
Stereographic() Constructor with default parameters = North Polar
Stereographic(double latt, double lont, double scale) Construct a Stereographic Projection.
Stereographic(double lat_ts_deg, double latt_deg, double lont_deg, boolean north) Construct a polar Stereographic Projection, from the "natural origin" and the tangent point, calculating the scale factor.
Stereographic(double latt, double lont, double scale, double false_easting, double false_northing) Construct a Stereographic Projection.
Stereographic(double latt, double lont, double scale, double false_easting, double false_northing, double radius) Construct a Stereographic Projection.

Method Summary

Modifier and Type	Method and Description
Projection	constructCopy() copy constructor - avoid clone !!
boolean	crossSeam(ProjectionPoint pt1, ProjectionPoint pt2) Does the line between these two points cross the projection "seam".
boolean	equals(Object o)
static Stereographic	factory(double latt, double lont, double latTrue) Construct a Stereographic Projection using latitude of true scale and calculating scale factor.
double	getEarthRadius()
double	getFalseEasting() Get the false easting, in km.
double	getFalseNorthing() Get the false northing, in km.
double	getNaturalOriginLat() Get the latitude at natural origin in degrees
double	getScale() Get the scale
double	getTangentLat() Get the tangent latitude in degrees
double	getTangentLon() Get the tangent longitude in degrees
int	hashCode()
boolean	isNorth()
boolean	isPolar()
ProjectionPoint	latLonToProj(LatLonPoint latLon) Convert a LatLonPoint to projection coordinates.
String	paramsToString() String representation of the projection parameters.
LatLonPoint	projToLatLon(ProjectionPoint world) Convert projection coordinates to a LatLonPoint.
String	toString() Get a String representation of this projection.

Methods inherited from class ucar.unidata.geoloc.projection.AbstractProjection

addParameter, addParameter, addParameter, addParameter, findProjectionParameter, getClassName, getHeader, getMinOrMaxLon, getName, getProjectionAttributes, getProjectionParameters, getProjectionTypeLabel, isLatLon, latLonToProjBB, projToLatLonBB

Methods inherited from class java.lang.Object

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

Methods inherited from interface ucar.unidata.geoloc.Projection

latLonToProj, projToLatLon

Constructor Detail

Stereographic

public Stereographic()

Constructor with default parameters = North Polar

Stereographic

public Stereographic(double latt,
                     double lont,
                     double scale)

Construct a Stereographic Projection.

Parameters:

latt - tangent point of projection, also origin of projection coord system

lont - tangent point of projection, also origin of projection coord system

scale - scale factor at tangent point, "normally 1.0 but may be reduced"

Stereographic

public Stereographic(double latt,
                     double lont,
                     double scale,
                     double false_easting,
                     double false_northing)

Construct a Stereographic Projection.

Parameters:

latt - tangent point of projection, also origin of projection coord system

lont - tangent point of projection, also origin of projection coord system

scale - scale factor at tangent point, "normally 1.0 but may be reduced"

Stereographic

public Stereographic(double lat_ts_deg,
                     double latt_deg,
                     double lont_deg,
                     boolean north)

Construct a polar Stereographic Projection, from the "natural origin" and the tangent point, calculating the scale factor.

Parameters:

lat_ts_deg - Latitude at natural origin (degrees_north)

latt_deg - tangent point of projection (degrees_north)

lont_deg - tangent point of projection, also origin of projection coord system ((degrees_east)

north - true if north pole, false if south pole

Stereographic

public Stereographic(double latt,
                     double lont,
                     double scale,
                     double false_easting,
                     double false_northing,
                     double radius)

Construct a Stereographic Projection.

Parameters:

latt - tangent point of projection, also origin of projection coord system

lont - tangent point of projection, also origin of projection coord system

scale - scale factor at tangent point, "normally 1.0 but may be reduced"

false_easting - false easting in units of x coords

false_northing - false northing in units of y coords

radius - earth radius in km

Method Detail

factory

public static Stereographic factory(double latt,
                                    double lont,
                                    double latTrue)

Construct a Stereographic Projection using latitude of true scale and calculating scale factor.

Since the scale factor at lat = k = 2*k0/(1+sin(lat)) [Snyder,Working Manual p157] then to make scale = 1 at lat, set k0 = (1+sin(lat))/2

Parameters:

latt - tangent point of projection, also origin of projection coord system

lont - tangent point of projection, also origin of projection coord system

latTrue - latitude of true scale in degrees north; latitude where scale factor = 1.0

Returns:

Stereographic projection

constructCopy

public Projection constructCopy()

Description copied from class: AbstractProjection

copy constructor - avoid clone !!

Specified by:

constructCopy in class AbstractProjection

Returns:

a copy of this Projection.

getScale

public double getScale()

Get the scale

Returns:

the scale

getNaturalOriginLat

public double getNaturalOriginLat()

Get the latitude at natural origin in degrees

Returns:

latitude at natural origin

getTangentLon

public double getTangentLon()

Get the tangent longitude in degrees

Returns:

the origin longitude in degrees.

getTangentLat

public double getTangentLat()

Get the tangent latitude in degrees

Returns:

the origin latitude in degrees.

getEarthRadius

public double getEarthRadius()

isNorth

public boolean isNorth()

isPolar

public boolean isPolar()

paramsToString

public String paramsToString()

Description copied from interface: Projection

String representation of the projection parameters.

Specified by:

paramsToString in interface Projection

Specified by:

paramsToString in class AbstractProjection

toString

public String toString()

Description copied from class: AbstractProjection

Get a String representation of this projection.

Overrides:

toString in class AbstractProjection

Returns:

the name of the projection. This is what gets displayed when you add the projection object to a UI widget (e.g. label, combobox)

crossSeam

public boolean crossSeam(ProjectionPoint pt1,
                         ProjectionPoint pt2)

Does the line between these two points cross the projection "seam".

Parameters:

pt1 - the line goes between these two points

pt2 - the line goes between these two points

Returns:

false if there is no seam

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

getFalseEasting

public double getFalseEasting()

Get the false easting, in km.

Returns:

the false easting.

getFalseNorthing

public double getFalseNorthing()

Get the false northing, in km.

Returns:

the false northing.

latLonToProj

public ProjectionPoint latLonToProj(LatLonPoint latLon)

Description copied from interface: Projection

Convert a LatLonPoint to projection coordinates.

projToLatLon

public LatLonPoint projToLatLon(ProjectionPoint world)

Description copied from interface: Projection

Convert projection coordinates to a LatLonPoint.