org.apache.lucene.spatial.util

Class GeoProjectionUtils

java.lang.Object

org.apache.lucene.spatial.util.GeoProjectionUtils

public class GeoProjectionUtils
extends Object

Reusable geo-spatial projection utility methods.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Field Summary

Fields

Modifier and Type	Field and Description
static double	ECCENTRICITY first eccentricity (e)
static double	FLATTENING earth flattening factor (f)
static double	MAX_LAT_RADIANS max latitude value in radians
static double	MAX_LON_RADIANS max longitude value in radians
static double	MIN_LAT_RADIANS min latitude value in radians
static double	MIN_LON_RADIANS min longitude value in radians
static double	SEMIMAJOR_AXIS major (a) axis in meters
static double	SEMIMAJOR_AXIS2 major axis squared (a2)
static double	SEMIMINOR_AXIS minor (b) axis in meters
static double	SEMIMINOR_AXIS2 minor axis squared (b2)

Method Summary

Methods

Modifier and Type	Method and Description
static double	bearingGreatCircle(double lon1, double lat1, double lon2, double lat2) Finds the bearing (in degrees) between 2 geo points (lon, lat) using great circle arc
static double[]	ecfToENU(double x, double y, double z, double centerLon, double centerLat, double centerAlt, double[] enu) Convert from Earth-Centered-Fixed to Easting, Northing, Up Right Hand System
static double[]	ecfToLLA(double x, double y, double z, double[] lla) Converts from geocentric earth-centered earth-fixed to geodesic lat/lon/alt
static double[]	enuToECF(double x, double y, double z, double centerLon, double centerLat, double centerAlt, double[] ecf) Convert from Easting, Northing, Up Right-Handed system to Earth Centered Fixed system
static double[]	enuToLLA(double x, double y, double z, double centerLon, double centerLat, double centerAlt, double[] lla) Converts from East North Up right-hand rule to lat lon alt in degrees
static double[]	llaToECF(double lon, double lat, double alt, double[] ecf) Converts from geodesic lon lat alt to geocentric earth-centered earth-fixed
static double[]	llaToENU(double lon, double lat, double alt, double centerLon, double centerLat, double centerAlt, double[] enu) Converts from lat lon alt (in degrees) to East North Up right-hand coordinate system
static double[]	pointFromLonLatBearingGreatCircle(double lon, double lat, double bearing, double dist, double[] pt) Finds a point along a bearing from a given lon,lat geolocation using great circle arc
static double[]	pointFromLonLatBearingVincenty(double lon, double lat, double bearing, double dist, double[] pt) Finds a point along a bearing from a given lon,lat geolocation using vincenty's distance formula

Methods inherited from class java.lang.Object

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

Field Detail

SEMIMAJOR_AXIS

public static final double SEMIMAJOR_AXIS

major (a) axis in meters

See Also:

Constant Field Values

FLATTENING

public static final double FLATTENING

earth flattening factor (f)

See Also:

Constant Field Values

SEMIMINOR_AXIS

public static final double SEMIMINOR_AXIS

minor (b) axis in meters

See Also:

Constant Field Values

ECCENTRICITY

public static final double ECCENTRICITY

first eccentricity (e)

SEMIMAJOR_AXIS2

public static final double SEMIMAJOR_AXIS2

major axis squared (a2)

See Also:

Constant Field Values

SEMIMINOR_AXIS2

public static final double SEMIMINOR_AXIS2

minor axis squared (b2)

See Also:

Constant Field Values

MIN_LON_RADIANS

public static final double MIN_LON_RADIANS

min longitude value in radians

See Also:

Constant Field Values

MIN_LAT_RADIANS

public static final double MIN_LAT_RADIANS

min latitude value in radians

See Also:

Constant Field Values

MAX_LON_RADIANS

public static final double MAX_LON_RADIANS

max longitude value in radians

See Also:

Constant Field Values

MAX_LAT_RADIANS

public static final double MAX_LAT_RADIANS

max latitude value in radians

See Also:

Constant Field Values

Method Detail

ecfToLLA

public static final double[] ecfToLLA(double x,
                double y,
                double z,
                double[] lla)

Converts from geocentric earth-centered earth-fixed to geodesic lat/lon/alt

Parameters:

x - Cartesian x coordinate

y - Cartesian y coordinate

z - Cartesian z coordinate

lla - 0: longitude 1: latitude: 2: altitude

Returns:

double array as 0: longitude 1: latitude 2: altitude

llaToECF

public static final double[] llaToECF(double lon,
                double lat,
                double alt,
                double[] ecf)

Converts from geodesic lon lat alt to geocentric earth-centered earth-fixed

Parameters:

lon - geodesic longitude

lat - geodesic latitude

alt - geodesic altitude

ecf - reusable earth-centered earth-fixed result

Returns:

either a new ecef array or the reusable ecf parameter

llaToENU

public static double[] llaToENU(double lon,
                double lat,
                double alt,
                double centerLon,
                double centerLat,
                double centerAlt,
                double[] enu)

Converts from lat lon alt (in degrees) to East North Up right-hand coordinate system

Parameters:

lon - longitude in degrees

lat - latitude in degrees

alt - altitude in meters

centerLon - reference point longitude in degrees

centerLat - reference point latitude in degrees

centerAlt - reference point altitude in meters

enu - result east, north, up coordinate

Returns:

east, north, up coordinate

enuToLLA

public static double[] enuToLLA(double x,
                double y,
                double z,
                double centerLon,
                double centerLat,
                double centerAlt,
                double[] lla)

Converts from East North Up right-hand rule to lat lon alt in degrees

Parameters:

x - easting (in meters)

y - northing (in meters)

z - up (in meters)

centerLon - reference point longitude (in degrees)

centerLat - reference point latitude (in degrees)

centerAlt - reference point altitude (in meters)

lla - resulting lat, lon, alt point (in degrees)

Returns:

lat, lon, alt point (in degrees)

ecfToENU

public static double[] ecfToENU(double x,
                double y,
                double z,
                double centerLon,
                double centerLat,
                double centerAlt,
                double[] enu)

Convert from Earth-Centered-Fixed to Easting, Northing, Up Right Hand System

Parameters:

x - ECF X coordinate (in meters)

y - ECF Y coordinate (in meters)

z - ECF Z coordinate (in meters)

centerLon - ENU origin longitude (in degrees)

centerLat - ENU origin latitude (in degrees)

centerAlt - ENU altitude (in meters)

enu - reusable enu result

Returns:

Easting, Northing, Up coordinate

enuToECF

public static double[] enuToECF(double x,
                double y,
                double z,
                double centerLon,
                double centerLat,
                double centerAlt,
                double[] ecf)

Convert from Easting, Northing, Up Right-Handed system to Earth Centered Fixed system

Parameters:

x - ENU x coordinate (in meters)

y - ENU y coordinate (in meters)

z - ENU z coordinate (in meters)

centerLon - ENU origin longitude (in degrees)

centerLat - ENU origin latitude (in degrees)

centerAlt - ENU origin altitude (in meters)

ecf - reusable ecf result

Returns:

ecf result coordinate

pointFromLonLatBearingVincenty

public static final double[] pointFromLonLatBearingVincenty(double lon,
                                      double lat,
                                      double bearing,
                                      double dist,
                                      double[] pt)

Finds a point along a bearing from a given lon,lat geolocation using vincenty's distance formula

Parameters:

lon - origin longitude in degrees

lat - origin latitude in degrees

bearing - azimuthal bearing in degrees

dist - distance in meters

pt - resulting point

Returns:

the point along a bearing at a given distance in meters

pointFromLonLatBearingGreatCircle

public static final double[] pointFromLonLatBearingGreatCircle(double lon,
                                         double lat,
                                         double bearing,
                                         double dist,
                                         double[] pt)

Finds a point along a bearing from a given lon,lat geolocation using great circle arc

Parameters:

lon - origin longitude in degrees

lat - origin latitude in degrees

bearing - azimuthal bearing in degrees

dist - distance in meters

pt - resulting point

Returns:

the point along a bearing at a given distance in meters

bearingGreatCircle

public static double bearingGreatCircle(double lon1,
                        double lat1,
                        double lon2,
                        double lat2)

Finds the bearing (in degrees) between 2 geo points (lon, lat) using great circle arc

Parameters:

lon1 - first point longitude in degrees

lat1 - first point latitude in degrees

lon2 - second point longitude in degrees

lat2 - second point latitude in degrees

Returns:

the bearing (in degrees) between the two provided points