Package elki.math.geodesy

Class SphericalCosineEarthModel

java.lang.Object

elki.math.geodesy.AbstractEarthModel

elki.math.geodesy.SphericalCosineEarthModel

All Implemented Interfaces:

EarthModel

public class SphericalCosineEarthModel
extends AbstractEarthModel

A simple spherical earth model using radius 6371009 m.

For distance computations, this variant uses the Cosine formula, which is faster but less accurate than the Haversince or Vincenty's formula.

Since:

0.6.0

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	SphericalCosineEarthModel.Par	Parameterization class.

Field Summary

Fields

Modifier and Type	Field	Description
static double	EARTH_RADIUS	Earth radius approximation in m.
static SphericalCosineEarthModel	STATIC	Spherical earth model, static instance.

Fields inherited from class elki.math.geodesy.AbstractEarthModel

a, b, e, esq, f, invf

Fields inherited from interface elki.math.geodesy.EarthModel

MODEL_ID

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	SphericalCosineEarthModel()	Constructor.

Method Summary

Modifier and Type	Method	Description
double	distanceRad(double lat1, double lng1, double lat2, double lng2)	Compute the geodetic distance between two surface coordinates.
double	ecefToLatRad(double x, double y, double z)	Convert a 3D coordinate pair to the corresponding latitude.
double[]	latLngRadToECEF(double lat, double lng)	Map a radians latitude, longitude pair to 3D X-Y-Z coordinates, using a spherical earth model.
double[]	latLngRadToECEF(double lat, double lng, double h)	Map a radians latitude, longitude pair to 3D X-Y-Z coordinates, using a spherical earth model.

Methods inherited from class elki.math.geodesy.AbstractEarthModel

distanceDeg, ecefToLatDeg, ecefToLatLngDegHeight, ecefToLatLngRadHeight, ecefToLngDeg, ecefToLngRad, getEquatorialRadius, getPolarDistance, latLngDegToECEF, latLngDegToECEF, minDistDeg, minDistRad, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

STATIC

public static final SphericalCosineEarthModel STATIC

Spherical earth model, static instance.

EARTH_RADIUS

public static final double EARTH_RADIUS

Earth radius approximation in m.

See Also:

Constant Field Values

Constructor Detail

SphericalCosineEarthModel

protected SphericalCosineEarthModel()

Constructor.

Method Detail

latLngRadToECEF

public double[] latLngRadToECEF(double lat,
                                double lng)

Description copied from interface: EarthModel

Map a radians latitude, longitude pair to 3D X-Y-Z coordinates, using a spherical earth model.

The coordinate system is usually chosen such that the earth rotates around the Z axis and X points to the prime meridian and Equator.

Specified by:

latLngRadToECEF in interface EarthModel

Overrides:

latLngRadToECEF in class AbstractEarthModel

Parameters:

lat - Latitude in radians

lng - Longitude in radians

Returns:

Coordinate triple, in meters.

latLngRadToECEF

public double[] latLngRadToECEF(double lat,
                                double lng,
                                double h)

Description copied from interface: EarthModel

Map a radians latitude, longitude pair to 3D X-Y-Z coordinates, using a spherical earth model.

The coordinate system is usually chosen such that the earth rotates around the Z axis and X points to the prime meridian and Equator.

Specified by:

latLngRadToECEF in interface EarthModel

Overrides:

latLngRadToECEF in class AbstractEarthModel

Parameters:

lat - Latitude in radians

lng - Longitude in radians

h - Height

Returns:

Coordinate triple, in meters.

ecefToLatRad

public double ecefToLatRad(double x,
                           double y,
                           double z)

Description copied from interface: EarthModel

Convert a 3D coordinate pair to the corresponding latitude.

Specified by:

ecefToLatRad in interface EarthModel

Overrides:

ecefToLatRad in class AbstractEarthModel

Parameters:

x - X value

y - Y value

z - Z value

Returns:

Latitude in radians

distanceRad

public double distanceRad(double lat1,
                          double lng1,
                          double lat2,
                          double lng2)

Description copied from interface: EarthModel

Compute the geodetic distance between two surface coordinates.

Specified by:

distanceRad in interface EarthModel

Overrides:

distanceRad in class AbstractEarthModel

Parameters:

lat1 - Latitude of first in radians.

lng1 - Longitude of first in radians.

lat2 - Latitude of second in radians.

lng2 - Longitude of second in radians.

Returns:

Distance in meters.