Package com.luciad.geodesy

Interface ILcdEllipsoid

All Superinterfaces:

Serializable

All Known Implementing Classes:

TLcdEllipsoid

public interface ILcdEllipsoid
extends Serializable

Interface that defines all ellipsoids. An ILcdEllipsoid represents an ellipsoid. Typically it is defined by:

• a semiMajorRadius (usually represented by the letter a ), and
• a semiMinorRadius (usually represented by the letter b ).

Other relevant values can be derived from the semiMajorRadius and the semiMinorRadius (in the formulas we use the shorthand representations):

• flattening (shorthand: f ): f = (a - b)/a
• eccentricitySquared: square of the eccentricity: e² = (a² - b² )/a²
• secondEccentricitySquared: square of the eccentricity based on minor axis (also called square of second eccentricity) : e' ² = (a² - b² )/b²
• n = (a - b)/(a + b)

An ILcdEllipsoid also has a name (of the type String) to refer to it.

Many methods of the ILcdEllipsoid refer to specialist's knowledge and will not be explained here. We refer for more information to following references:

1. Map Projections: Theory and Applications , 1990, Pearson
2. Coordinate Systems and Map Projections, 2nd edition, 1992, Maling
3. Map Projections: A Working Manual , 1987, Snyder
4. Map Projections: A Reference Manual , 1995, Bugayevski and Snyder
5. ...

Method Summary

Modifier and Type	Method	Description
void	bufferContour2DOf2DPolylineSFCT(ILcdPointList aPointList, double aWidth, ILcd2DEditablePoint[] a2DEditablePointArraySFCT)	Calculates the contour of the buffer/corridor along a given ILcdPointList at a given width.
void	bufferContour2DOfSegmentSFCT(ILcdPoint aStartPoint, ILcdPoint aEndPoint, double aWidth, ILcd2DEditablePoint[] a2DEditablePointArraySFCT)	Calculates the contour of the rectangle defined by aStartPoint, aEndPoint, and aWidth, as an array of 4 ILcd2DEditablePoint objects.
void	conformalSphericalLonLatPointSFCT(ILcdPoint aLLP, ILcd2DEditablePoint aLLPSFCT)	The conformal spherical longitude/latitude for a given geodetic longitude/latitude.
double	distanceToGeodesic(ILcdPoint aP1, ILcdPoint aP2, ILcdPoint aP3, double aAngle)	Calculates the distance between the geodesic aP1-aP2 and the point aP3, at a certain angle aAngle.
boolean	equals(Object aEllipsoid)	Overrides Object.equals.
double	forwardAzimuth2D(double aLongitude1, double aLatitude1, double aLongitude2, double aLatitude2)	Calculates the forward azimuth of the geodesic line from aP1 to aP2 in radians ! Only the (x,y) coordinates (longitude and latitude) of the ILcdPoint objects are taken into account.
double	forwardAzimuth2D(ILcdPoint aP1, ILcdPoint aP2)	Calculates the forward azimuth of the geodesic line from aP1 to aP2 in radians ! Only the (x,y) coordinates (longitude and latitude) of the ILcdPoint objects are taken into account.
default double	geoc2height(ILcdPoint aXYZGeocPoint)	Calculates the height above the ellipsoid for a point defined in an Earth Centered, Earth Fixed XYZ Cartesian coordinate system.
void	geoc2llhSFCT(ILcdPoint aXYZGeocPoint, ILcd3DEditablePoint aLLHPointSFCT)	Coordinate conversion between Earth Centered, Earth Fixed XYZ Cartesian coordinate system and latitude-longitude-ellipsoidal height for the ellipsoid.
double	geodesicArea(ILcdPoint[] aPts, int aN)	Calculates the geodesic surface area of a polygon given as an array of ILcdPoint objects.
double	geodesicDistance(double aLongitude1, double aLatitude1, double aLongitude2, double aLatitude2)	Calculates the shortest distance between two arbitrary ILcdPoint objects aP1 and aP2 on the ellipsoid in meters.
double	geodesicDistance(ILcdPoint aP1, ILcdPoint aP2)	Calculates the shortest distance between two arbitrary ILcdPoint objects aP1 and aP2 on the ellipsoid in meters.
void	geodesicPointSFCT(ILcdPoint aPoint, double aDistance, double aAzimuth, ILcd2DEditablePoint aGeodesicPointSFCT)	Determines the ILcdPoint aGeodesicPoint on the geodesic through (aP1.getX(), aP1.getY()) located at a distance aDistance and forward azimuth aAzimuth.
void	geodesicPointSFCT(ILcdPoint aP1, ILcdPoint aP2, double aK, ILcd2DEditablePoint aGeodesicPointSFCT)	Sets aGeodesicPointSFCT to an ILcdPoint on the geodesic line through the point aP1 and the point aP2, located at a fraction aK of the (shortest) distance between aP1 and aP2.
double	get1OverF()	Gets the reciprocal of the flattening 1/f.
double	getA()	Gets the semiMajorRadius a.
double	getAuxRadius()	Radius of auxiliary sphere of the ellipsoid.
double	getB()	Gets the semiMinorRadius b.
double	getConformalRadius()	Radius of a sphere such that its meridional arc from 0 -> 90 degrees is equal to the corresponding meridional arc on the ellipsoid.
double	getE()	Gets the eccentricity e which is always positive.
double	getE2()	Gets the eccentricitySquared e2 = (a2 - b2)/a2.
double	getEMinor2()	Gets the secondEccentricitySquared e' 2 = (a2 - b2 )/b2.
double	getF()	Gets the flattening f.
double	getN()	Gets n = (a - b)/(a + b).
String	getName()	Gets the name of this ILcdEllipsoid.
void	intersection2DLSSFCT(double aLon1, double aLat1, double aLon2, double aLat2, double aLon3, double aLat3, double aLon4, double aLat4, ILcd2DEditablePoint aLLPSFCT)	Calculates the intersection of two geodesic lines going through the given coordinates.
void	intersection2DLSSFCT(ILcdPoint aP1, ILcdPoint aP2, ILcdPoint aP3, ILcdPoint aP4, ILcd2DEditablePoint aLLPSFCT)	Calculates the intersection of two geodesic lines going containing the given coordinates.
boolean	intersects2DLS(double aLon1, double aLat1, double aLon2, double aLat2, double aLon3, double aLat3, double aLon4, double aLat4)	Checks whether two geodesic line segments with the given coordinates intersect.
boolean	intersects2DLS(ILcdPoint aP1, ILcdPoint aP2, ILcdPoint aP3, ILcdPoint aP4)	Checks whether two geodesic line segments intersect.
void	inverseConformalSphericalLonLatPointSFCT(ILcdPoint aLLP, ILcd2DEditablePoint aLLPSFCT)	The inverse transformation of the conformal spherical longitude/latitude.
boolean	isSphere()	Checks whether ellipsoid is the special case sphere.
void	llh2geocSFCT(ILcdPoint aLLHPoint, ILcd3DEditablePoint aXYZGeocentricPointSFCT)	Coordinate conversion between latitude-longitude-ellipsoidal height for the ellipsoid and Earth Centered, Earth Fixed XYZ Cartesian coordinate system.
double	meridionalArcDistance(double aLatitude)	Calculates the meridional arc distance in meters.
double	meridionalArcDistance(double aLatitude, double aCosLat, double aSinLat)	Calculates the meridional arc distance in meters.
double	radiusEuler(double aLatitude, double aAzimuth)	Euler radius of the ellipsoid at a given latitude aLatitude and a given azimuth aAzimuth.
double	radiusEuler(double aLatitude, double aSinLat, double aAzimuth, double aCosAzimuth, double aSinAzimuth)	Euler radius of the ellipsoid at a given latitude aLatitude and a given azimuth aAzimuth.
double	radiusGaussian(double aLatitude)	The Gaussian curvature radius is the geometric mean of the vertical and the meridional radius.
double	radiusGaussian(double aLatitude, double aSinLat)	The Gaussian curvature radius is the geometric mean of the vertical and the meridional radius.
double	radiusMeridian(double aLatitude)	Radius of curvature in prime meridian at a given geodetic latitude.
double	radiusMeridian(double aLatitude, double aSinLat)	Radius of curvature in prime meridian at a given geodetic latitude.
double	radiusVertical(double aLatitude)	Radius of curvature in prime vertical at a given geodetic latitude.
double	radiusVertical(double aLatitude, double aSinLat)	Radius of curvature in prime vertical at a given geodetic latitude.
double	rhumblineAzimuth2D(ILcdPoint aP1, ILcdPoint aP2)	Calculates the azimuth of the rhumbline from aP1 to aP2 in degrees! Only the (x,y) coordinates (longitude and latitude) of the ILcdPoint objects are taken into account.
double	rhumblineDistance(ILcdPoint aP1, ILcdPoint aP2)	Calculates the distance between two arbitrary ILcdPoint objects aP1 and aP2 on the ellipsoid in meters following a path with constant azimuth.
void	rhumblinePointSFCT(ILcdPoint aPoint, double aDistance, double aAzimuth, ILcd2DEditablePoint aRhumblinePointSFCT)	Determines the ILcdPoint aRhumblinePointSFCT on the rhumbline (a path with a constant bearing) through (aP1.getX(), aP1.getY()) located at a distance aDistance and forward azimuth aAzimuth.

Method Details

getA

double getA()

Gets the semiMajorRadius a.

Returns:

the SemiMajorRadius a.

getB

double getB()

Gets the semiMinorRadius b.

Returns:

the SemiMinorRadius b.

get1OverF

double get1OverF()

Gets the reciprocal of the flattening 1/f.

Returns:

the reciprocal of the flattening 1/f.

getF

double getF()

Gets the flattening f.

Returns:

the flattening f.

getE

double getE()

Gets the eccentricity e which is always positive.

Returns:

the eccentricity e which is always positive.

getE2

double getE2()

Gets the eccentricitySquared e² = (a² - b²)/a².

Returns:

the eccentricitySquared e² = (a² - b² )/a².

getEMinor2

double getEMinor2()

Gets the secondEccentricitySquared e' ² = (a² - b² )/b².

Returns:

the secondEccentricitySquared e' ² = (a² - b² )/b² .

getN

double getN()

Gets n = (a - b)/(a + b).

Returns:

n = (a - b)/(a + b).

isSphere

boolean isSphere()

Checks whether ellipsoid is the special case sphere.

Returns:

true if and only if ellipsoid is a sphere.

radiusVertical

double radiusVertical(double aLatitude)

Radius of curvature in prime vertical at a given geodetic latitude. Commonly referred to with a Greek letter n.

Parameters:

aLatitude - latitude, in degrees.

Returns:

the radius of curvature in prime vertical at a given geodetic latitude.

See Also:

• radiusVertical(double, double)

radiusVertical

double radiusVertical(double aLatitude,
 double aSinLat)

Radius of curvature in prime vertical at a given geodetic latitude. Commonly referred to with a Greek letter n.

Parameters:

aLatitude - latitude, in degrees.

aSinLat - the sine of the latitude.

Returns:

the radius of curvature in prime vertical at a given geodetic latitude.

See Also:

• radiusVertical(double)

radiusMeridian

double radiusMeridian(double aLatitude)

Radius of curvature in prime meridian at a given geodetic latitude.

Parameters:

aLatitude - latitude, in degrees.

Returns:

the radius of curvature in prime meridian at a given geodetic latitude.

See Also:

• radiusMeridian(double, double)

radiusMeridian

double radiusMeridian(double aLatitude,
 double aSinLat)

Radius of curvature in prime meridian at a given geodetic latitude.

Parameters:

aLatitude - latitude, in degrees.

aSinLat - the sine of the latitude.

Returns:

the radius of curvature in prime meridian at a given geodetic latitude.

meridionalArcDistance

double meridionalArcDistance(double aLatitude)

Calculates the meridional arc distance in meters. The length of the arc measured from the plane of the equator to a point at latitude aLatitude. Since the earth is represented by a rotational ellipsoid the longitude is irrelevant.

Parameters:

aLatitude - latitude, in degrees.

Returns:

the meridional arc distance in meters.

See Also:

• meridionalArcDistance(double, double, double)

meridionalArcDistance

double meridionalArcDistance(double aLatitude,
 double aCosLat,
 double aSinLat)

Calculates the meridional arc distance in meters. The length of the arc measured from the plane of the equator to a point at latitude aLatitude. Since the earth is represented by a rotational ellipsoid the longitude is irrelevant.

Parameters:

aLatitude - latitude, in degrees.

aCosLat - the cosine of the latitude.

aSinLat - the sine of the latitude.

Returns:

the meridional arc distance in meters.

geodesicDistance

double geodesicDistance(ILcdPoint aP1,
 ILcdPoint aP2)

Calculates the shortest distance between two arbitrary ILcdPoint objects aP1 and aP2 on the ellipsoid in meters. The curve that represents this shortest path is known as the geodesic curve. Only the longitude and the latitude of the two geodetic coordinates are taken into account.

Parameters:

aP1 - start point of geodesic line segment.

aP2 - end point of geodesic line segment.

Returns:

the shortest distance between aP1 and aP2 on the ellipsoid in meters.

geodesicDistance

double geodesicDistance(double aLongitude1,
 double aLatitude1,
 double aLongitude2,
 double aLatitude2)

Calculates the shortest distance between two arbitrary ILcdPoint objects aP1 and aP2 on the ellipsoid in meters.

Parameters:

aLongitude1 - longitude, in degrees, of the start point of the geodesic line segment.

aLatitude1 - latitude, in degrees, of the start point of the geodesic line segment.

aLongitude2 - longitude, in degrees, of the end point of the geodesic line segment.

aLatitude2 - latitude, in degrees, of the end point of the geodesic line segment.

Returns:

the same as geodesicDistance(ILcdPoint aP1, ILcdPoint aP2) if aP1 would be an ILcdPoint with lon-lat coordinates (aLongitude1,aLatitude1) and aP2 would be a ILcdPoint with lon-lat coordinates (aLongitude2,aLatitude2).

See Also:

• geodesicDistance(ILcdPoint aP1, ILcdPoint aP2)

geodesicArea

double geodesicArea(ILcdPoint[] aPts,
 int aN)

Calculates the geodesic surface area of a polygon given as an array of ILcdPoint objects. The segments of the polygon must not be self-intersecting. Only the longitude and latitude of the coordinates are taken into account.

Constraint: (aN > 2) and (aPts.length > aN).

Parameters:

aPts - an array of ILcdPoint objects.

aN - aPts[0..aN-1] defines the polygon on the ellipsoid.

Returns:

the geodesic surface area of a polygon on the ellipsoid.

forwardAzimuth2D

double forwardAzimuth2D(ILcdPoint aP1,
 ILcdPoint aP2)

Calculates the forward azimuth of the geodesic line from aP1 to aP2 in radians ! Only the (x,y) coordinates (longitude and latitude) of the ILcdPoint objects are taken into account.

The forward azimuth lies between [0.0, 2.0*Math.PI], with 0.0 north, clockwise.

Parameters:

aP1 - start point of the geodesic line segment.

aP2 - end point of the geodesic line segment.

Returns:

the forward azimuth from aP1 to aP2 in radians!

forwardAzimuth2D

double forwardAzimuth2D(double aLongitude1,
 double aLatitude1,
 double aLongitude2,
 double aLatitude2)

Calculates the forward azimuth of the geodesic line from aP1 to aP2 in radians ! Only the (x,y) coordinates (longitude and latitude) of the ILcdPoint objects are taken into account.

The forward azimuth lies between [0.0, 2.0*Math.PI], with 0.0 north, clockwise.

Parameters:

aLongitude1 - longitude, in degrees, of the start point of the geodesic line segment.

aLatitude1 - latitude, in degrees, of the start point of the geodesic line segment.

aLongitude2 - longitude, in degrees, of the end point of the geodesic line segment.

aLatitude2 - latitude, in degrees, of the end point of the geodesic line segment.

Returns:

the forward azimuth from (aLongitude1,aLatitude1) to (aLongitude2,aLatitude2) in radians!

geodesicPointSFCT

void geodesicPointSFCT(ILcdPoint aP1,
 ILcdPoint aP2,
 double aK,
 ILcd2DEditablePoint aGeodesicPointSFCT)

Sets aGeodesicPointSFCT to an ILcdPoint on the geodesic line through the point aP1 and the point aP2, located at a fraction aK of the (shortest) distance between aP1 and aP2.

Parameters:

aP1 - first 2D point on the ellipsoid [aP1.getX(), aP1.getY()].

aP2 - second 2D point on the ellipsoid [aP2.getX(), aP2.getY()].

aK - fraction between 0.0 and 1.0.

aGeodesicPointSFCT - side effect parameter that contains the result upon return of the method.

geodesicPointSFCT

void geodesicPointSFCT(ILcdPoint aPoint,
 double aDistance,
 double aAzimuth,
 ILcd2DEditablePoint aGeodesicPointSFCT)

Determines the ILcdPoint aGeodesicPoint on the geodesic through (aP1.getX(), aP1.getY()) located at a distance aDistance and forward azimuth aAzimuth.

Parameters:

aPoint - ILcdPoint on the ellipsoid.

aDistance - distance expressed in meters. If the distance is smaller than 0, this method will return the input point as result.

aAzimuth - forward azimuth expressed in degrees.

aGeodesicPointSFCT - side effect parameter that contains the result upon return of the method.

rhumblineDistance

double rhumblineDistance(ILcdPoint aP1,
 ILcdPoint aP2)

Calculates the distance between two arbitrary ILcdPoint objects aP1 and aP2 on the ellipsoid in meters following a path with constant azimuth. The curve that represents this path is known as the rhumbline. Only the longitude and the latitude of the two geodetic coordinates are taken into account.

Parameters:

aP1 - start point of rhumbline segment.

aP2 - end point of rhumbline segment.

Returns:

the rhumbline distance between aP1 and aP2 on the ellipsoid in meters.

rhumblineAzimuth2D

double rhumblineAzimuth2D(ILcdPoint aP1,
 ILcdPoint aP2)

Calculates the azimuth of the rhumbline from aP1 to aP2 in degrees! Only the (x,y) coordinates (longitude and latitude) of the ILcdPoint objects are taken into account.

The forward azimuth lies between [0.0, 360.0], with 0.0 north, clockwise.

Parameters:

aP1 - start point of rhumbline segment.

aP2 - end point of rhumbline segment.

Returns:

the forward azimuth from aP1 to aP2 in DEGREES!

rhumblinePointSFCT

void rhumblinePointSFCT(ILcdPoint aPoint,
 double aDistance,
 double aAzimuth,
 ILcd2DEditablePoint aRhumblinePointSFCT)

Determines the ILcdPoint aRhumblinePointSFCT on the rhumbline (a path with a constant bearing) through (aP1.getX(), aP1.getY()) located at a distance aDistance and forward azimuth aAzimuth.

Parameters:

aPoint - ILcdPoint on the ellipsoid.

aDistance - distance expressed in meters.

aAzimuth - forward azimuth expressed in degrees.

aRhumblinePointSFCT - ILcdPoint on the ellipsoid.

conformalSphericalLonLatPointSFCT

void conformalSphericalLonLatPointSFCT(ILcdPoint aLLP,
 ILcd2DEditablePoint aLLPSFCT)

The conformal spherical longitude/latitude for a given geodetic longitude/latitude. These lon-lat-points are represented by ILcdPoint objects. A conformal projection is a projection for which the shape of a figure on the earth is preserved on the map. For a thorough understanding the reader is referred to the references.

Parameters:

aLLP - Geodetic point on the ellipsoid.

aLLPSFCT - Geodetic point on the conformal sphere.

inverseConformalSphericalLonLatPointSFCT

void inverseConformalSphericalLonLatPointSFCT(ILcdPoint aLLP,
 ILcd2DEditablePoint aLLPSFCT)

The inverse transformation of the conformal spherical longitude/latitude.

Parameters:

aLLP - Geodetic point on the conformal sphere.

aLLPSFCT - Geodetic point on the ellipsoid.

See Also:

• conformalSphericalLonLatPointSFCT(com.luciad.shape.ILcdPoint, com.luciad.shape.shape2D.ILcd2DEditablePoint)

geoc2llhSFCT

void geoc2llhSFCT(ILcdPoint aXYZGeocPoint,
 ILcd3DEditablePoint aLLHPointSFCT)

Coordinate conversion between Earth Centered, Earth Fixed XYZ Cartesian coordinate system and latitude-longitude-ellipsoidal height for the ellipsoid.

Parameters:

aXYZGeocPoint - geocentric 3D point.

aLLHPointSFCT - lonLatHeight coordinates to be set.

geoc2height

default double geoc2height(ILcdPoint aXYZGeocPoint)

Calculates the height above the ellipsoid for a point defined in an Earth Centered, Earth Fixed XYZ Cartesian coordinate system.

Parameters:

aXYZGeocPoint - geocentric 3D point

Returns:

the height above the ellipsoid

Since:

2019.0

llh2geocSFCT

void llh2geocSFCT(ILcdPoint aLLHPoint,
 ILcd3DEditablePoint aXYZGeocentricPointSFCT)

Coordinate conversion between latitude-longitude-ellipsoidal height for the ellipsoid and Earth Centered, Earth Fixed XYZ Cartesian coordinate system.

Parameters:

aLLHPoint - lonLatHeight point.

aXYZGeocentricPointSFCT - Geocentric coordinates to be set.

radiusEuler

double radiusEuler(double aLatitude,
 double aAzimuth)

Euler radius of the ellipsoid at a given latitude aLatitude and a given azimuth aAzimuth. The euler radius is the mean radius of the spheroidal arc at the given latitude for the given azimuth.

Parameters:

aLatitude - latitude, in arc degrees.

aAzimuth - azimuth, in RADIANS .

Returns:

the Euler radius of the ellipsoid at the given latitude.

See Also:

• radiusEuler(double, double, double, double, double)

radiusEuler

double radiusEuler(double aLatitude,
 double aSinLat,
 double aAzimuth,
 double aCosAzimuth,
 double aSinAzimuth)

Euler radius of the ellipsoid at a given latitude aLatitude and a given azimuth aAzimuth. The euler radius is the mean radius of the spheroidal arc at the given latitude for the given azimuth.

Parameters:

aLatitude - latitude, in arc degrees.

aSinLat - the sine of the latitude.

aAzimuth - azimuth, in RADIANS .

aCosAzimuth - the cosine of the azimuth.

aSinAzimuth - the sine of the azimuth.

Returns:

the Euler radius of the ellipsoid at the given latitude.

radiusGaussian

double radiusGaussian(double aLatitude)

The Gaussian curvature radius is the geometric mean of the vertical and the meridional radius. See p. 78 of Coordinate Systems and Map Projections , 2nd edition, 1992, Maling. Often used as the basis for conformal spherical calculations.

Parameters:

aLatitude - latitude, in degrees

Returns:

the Gaussian curvature radius.

See Also:

• radiusMeridian(double)
• radiusVertical(double)

radiusGaussian

double radiusGaussian(double aLatitude,
 double aSinLat)

The Gaussian curvature radius is the geometric mean of the vertical and the meridional radius. See p. 78 of Coordinate Systems and Map Projections , 2nd edition, 1992, Maling. Often used as the basis for conformal spherical calculations.

Parameters:

aLatitude - latitude, in degrees

aSinLat - the sine of the latitude.

Returns:

the Gaussian curvature radius.

See Also:

• radiusMeridian(double)
• radiusVertical(double)

getAuxRadius

double getAuxRadius()

Radius of auxiliary sphere of the ellipsoid. The simplest choice is to take the semiMajorAxis of the ellipsoid.

Returns:

The auxRadius value.

getConformalRadius

double getConformalRadius()

Radius of a sphere such that its meridional arc from 0 -> 90 degrees is equal to the corresponding meridional arc on the ellipsoid.

Returns:

the radius of a sphere such that its meridional arc from 0 -> 90 degrees is equal to the corresponding meridional arc on the ellipsoid.

intersects2DLS

boolean intersects2DLS(ILcdPoint aP1,
 ILcdPoint aP2,
 ILcdPoint aP3,
 ILcdPoint aP4)

Checks whether two geodesic line segments intersect. Any intersection will always lie on both segments (i.e. between aP1 and aP2, and between aP3 and aP4).

Refer to TLcdEllipsoidUtil.intersectionGeodesicGeodesic(com.luciad.shape.ILcdPoint, com.luciad.shape.ILcdPoint, com.luciad.shape.ILcdPoint, com.luciad.shape.ILcdPoint, com.luciad.geodesy.ILcdEllipsoid, com.luciad.shape.shape2D.ILcd2DEditablePoint) for checking the intersection of entire geodesics.

Parameters:

aP1 - start point of the first line segment.

aP2 - end point of the first line segment.

aP3 - start point of the second line segment.

aP4 - end point of the second line segment.

Returns:

true if the segments intersect each other, false otherwise.

intersects2DLS

boolean intersects2DLS(double aLon1,
 double aLat1,
 double aLon2,
 double aLat2,
 double aLon3,
 double aLat3,
 double aLon4,
 double aLat4)

Checks whether two geodesic line segments with the given coordinates intersect. Any intersection will always lie on both segments (i.e. between the points (aLon1,aLat1) and (aLon2,aLat2), and between (aLon3,aLat3) and (aLon4,aLat4).

Refer to TLcdEllipsoidUtil.intersectionGeodesicGeodesic(com.luciad.shape.ILcdPoint, com.luciad.shape.ILcdPoint, com.luciad.shape.ILcdPoint, com.luciad.shape.ILcdPoint, com.luciad.geodesy.ILcdEllipsoid, com.luciad.shape.shape2D.ILcd2DEditablePoint) for checking the intersection of entire geodesics.

Parameters:

aLon1 - longitude of the start point of the first geodesic line segment.

aLat1 - latitude of the start point of the first geodesic line segment.

aLon2 - longitude of the end point of the first geodesic line segment.

aLat2 - latitude of the end point of the first geodesic line segment.

aLon3 - longitude of the start point of the first geodesic line segment.

aLat3 - latitude of the start point of the first geodesic line segment.

aLon4 - longitude of the end point of the first geodesic line segment.

aLat4 - latitude of the end point of the first geodesic line segment.

Returns:

true if geodesic line segments intersect each other, false otherwise.

intersection2DLSSFCT

void intersection2DLSSFCT(ILcdPoint aP1,
 ILcdPoint aP2,
 ILcdPoint aP3,
 ILcdPoint aP4,
 ILcd2DEditablePoint aLLPSFCT)

Calculates the intersection of two geodesic lines going containing the given coordinates. The intersection will always lie on both segments (i.e. between aP1 and aP2, and between aP3 and aP4).

Refer to TLcdEllipsoidUtil.intersectionGeodesicGeodesic(com.luciad.shape.ILcdPoint, com.luciad.shape.ILcdPoint, com.luciad.shape.ILcdPoint, com.luciad.shape.ILcdPoint, com.luciad.geodesy.ILcdEllipsoid, com.luciad.shape.shape2D.ILcd2DEditablePoint) for checking the intersection of entire geodesics.

Parameters:

aP1 - start point of the first geodesic line segment.

aP2 - end point of the first geodesic line segment.

aP3 - start point of the second geodesic line segment.

aP4 - end point of the second geodesic line segment.

aLLPSFCT - represents the intersection point on return of the method.

Throws:

RuntimeException - when the geodesic lines do not intersect.

intersection2DLSSFCT

void intersection2DLSSFCT(double aLon1,
 double aLat1,
 double aLon2,
 double aLat2,
 double aLon3,
 double aLat3,
 double aLon4,
 double aLat4,
 ILcd2DEditablePoint aLLPSFCT)

Calculates the intersection of two geodesic lines going through the given coordinates. Any intersection will always lie on both segments (i.e. between the points (aLon1,aLat1) and (aLon2,aLat2), and between (aLon3,aLat3) and (aLon4,aLat4).

Refer to TLcdEllipsoidUtil.intersectionGeodesicGeodesic(com.luciad.shape.ILcdPoint, com.luciad.shape.ILcdPoint, com.luciad.shape.ILcdPoint, com.luciad.shape.ILcdPoint, com.luciad.geodesy.ILcdEllipsoid, com.luciad.shape.shape2D.ILcd2DEditablePoint) for checking the intersection of entire geodesics.

Parameters:

aLon1 - longitude of the start point of the first geodesic line segment.

aLat1 - latitude of the start point of the first geodesic line segment.

aLon2 - longitude of the end point of the first geodesic line segment.

aLat2 - latitude of the end point of the first geodesic line segment.

aLon3 - longitude of the start point of the first geodesic line segment.

aLat3 - latitude of the start point of the first geodesic line segment.

aLon4 - longitude of the end point of the first geodesic line segment.

aLat4 - latitude of the end point of the first geodesic line segment.

aLLPSFCT - represents the intersection point on return of the method.

Throws:

RuntimeException - when the geodesic lines do not intersect.

distanceToGeodesic

double distanceToGeodesic(ILcdPoint aP1,
 ILcdPoint aP2,
 ILcdPoint aP3,
 double aAngle)

Calculates the distance between the geodesic aP1-aP2 and the point aP3, at a certain angle aAngle. Returns result in degrees.

Parameters:

aP1 - first end point of defined geodesic line.

aP2 - seconds end point of defined geodesic line.

aP3 - point from which the distance has to be calculated.

aAngle - defines the angle between the geodesic defined by aP3 and the point of crossing and the geodesic defined by aP1 and aP2. Should be specified in degrees.

Returns:

the distance in degrees.

bufferContour2DOfSegmentSFCT

void bufferContour2DOfSegmentSFCT(ILcdPoint aStartPoint,
 ILcdPoint aEndPoint,
 double aWidth,
 ILcd2DEditablePoint[] a2DEditablePointArraySFCT)

Calculates the contour of the rectangle defined by aStartPoint, aEndPoint, and aWidth, as an array of 4 ILcd2DEditablePoint objects. The ordering of the points of the contour is clockwise starting from the first point of the rectangle.

Because there are only 4 points used to define the contour, the contour representation becomes less accurate when the start and end point are further removed from each other: the connected contour lines no longer lie at the given distance from the axis at each intermediate point. For a more accurate calculation of a buffer contour that uses additional contour points if necessary, please refer to TLcdEllipsoidUtil#computeBufferContour2D.

Parameters:

aStartPoint - start point of buffer segment.

aEndPoint - end point of buffer segment.

aWidth - distance from the line segment to the contour in meters.

a2DEditablePointArraySFCT - an initialized array of 4 ILcd2DEditablePoint objects, which will represent the contour polygon.

bufferContour2DOf2DPolylineSFCT

void bufferContour2DOf2DPolylineSFCT(ILcdPointList aPointList,
 double aWidth,
 ILcd2DEditablePoint[] a2DEditablePointArraySFCT)

Calculates the contour of the buffer/corridor along a given ILcdPointList at a given width. The ordering of the points of the contour is clockwise starting from the first point of the rectangle.

This implementation has the following limitations:

• contours with holes (i.e., caused by axis intersections) cannot be represented, since the contour is modeled as an ILcd2DEditablePoint array,
• the corners of the contour at the axis points are sharp instead of rounded, which make it less suitable for buffers that have sharp angles between its consecutive axis segments; it has also has as consequence that the distance between the contour and the axis exceeds the given buffer distance in the corners,
• the calculated contour is only an estimate, because it uses a reduced number of contour points; when the start and end point of a segment are further removed from each other, the connected contour lines no longer lie at the given distance from the axis at each intermediate point.

For an improved calculation of a buffer contour that overcomes these limitations, please refer to TLcdEllipsoidUtil#computeBufferContour2D.

Parameters:

aPointList - the axis of the buffer.

aWidth - distance from the axis to the contour in meters.

a2DEditablePointArraySFCT - an initialized array of aPointList.getPointCount() * 2 ILcd2DEditablePoint objects, which will represent the contour polygon.

equals

boolean equals(Object aEllipsoid)

Overrides Object.equals.

Overrides:

equals in class Object

Parameters:

aEllipsoid - Object to be checked on.

Returns:

true if both objects are equal.

getName

String getName()

Gets the name of this ILcdEllipsoid.

Returns:

the name of this ILcdEllipsoid.