au.org.ala.biocache.util

Class SpatialUtils

java.lang.Object

au.org.ala.biocache.util.SpatialUtils

public class SpatialUtils
extends Object

Supplies spatial utilities that can be used for the geospatial seaches

Author:

Natasha Carter

Field Summary

Fields

Modifier and Type	Field and Description
static double	EARTH_RADIUS_EQUATORIAL The equatorial radius of the earth [6378.1370 km] (see Wikipedia) as derived from the WGS-84 ellipsoid.
static double	EARTH_RADIUS_MEAN The Authalic mean radius (Ar) of the earth [6371.0072 km] (see Wikipedia).
static double	EARTH_RADIUS_POLAR The polar radius of the earth [6356.7523 km] (see Wikipedia) as derived from the WGS-84 ellipsoid.

Constructor Summary

Constructors

Constructor and Description
SpatialUtils()

Method Summary

Methods

Modifier and Type	Method and Description
static Float	convertToDegrees(Float kilometres) Turns the number of km in a degreee representation based on a conversion factor in Australia.
static double	degreesLatPerKm(double lat, double lon) Returns the number of degrees of latitude per km at a given Location.
static String	getInverseWKT(String wkt) Deprecated. No longer necessary because the SOLR spatial support negated areas in the query.
static String	getWKTAsUnions(String wkt) Returns a GeometryCollection as a UNION of geometries
static String	getWKTQuery(String spatialField, String wkt, boolean negated) Build up a WKT query.
static void	main(String[] args)
static double	radiusAtLocation(double lat, double lon) Returns the radius of the earth at the latitude of the supplied Location (see Wikipedia for source).

Methods inherited from class java.lang.Object

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

Field Detail

EARTH_RADIUS_MEAN

public static final double EARTH_RADIUS_MEAN

The Authalic mean radius (Ar) of the earth [6371.0072 km] (see Wikipedia).

See Also:

Constant Field Values

EARTH_RADIUS_EQUATORIAL

public static final double EARTH_RADIUS_EQUATORIAL

The equatorial radius of the earth [6378.1370 km] (see Wikipedia) as derived from the WGS-84 ellipsoid.

See Also:

Constant Field Values

EARTH_RADIUS_POLAR

public static final double EARTH_RADIUS_POLAR

The polar radius of the earth [6356.7523 km] (see Wikipedia) as derived from the WGS-84 ellipsoid.

See Also:

Constant Field Values

Constructor Detail

SpatialUtils

public SpatialUtils()

Method Detail

getInverseWKT

@Deprecated
public static String getInverseWKT(String wkt)

Deprecated. No longer necessary because the SOLR spatial support negated areas in the query.

This method return an inverse WKT string by subtractoing the WKT from the earth.

Parameters:

wkt -

Returns:

main

public static void main(String[] args)

radiusAtLocation

public static double radiusAtLocation(double lat,
                      double lon)

Returns the radius of the earth at the latitude of the supplied Location (see Wikipedia for source).

Parameters:

p - the Location at which to compute the earth's radius

Returns:

the earth's radius at the supplied Location

degreesLatPerKm

public static double degreesLatPerKm(double lat,
                     double lon)

Returns the number of degrees of latitude per km at a given Location. This can be used to convert between km-based and degree-based grid spacing. The calculation takes into account the shape of the earth (oblate spheroid) and scales the conversion accordingly.

Parameters:

p - the Location at which to conversion value

Returns:

the number of decimal degrees latitude per km at a given Location

See Also:

#radiusAtLocation(Location)

convertToDegrees

public static Float convertToDegrees(Float kilometres)

Turns the number of km in a degreee representation based on a conversion factor in Australia. TODO consider making the conversion factor more dynamic based on supplied lat and long

Parameters:

kilometres -

Returns:

getWKTAsUnions

public static String getWKTAsUnions(String wkt)

Returns a GeometryCollection as a UNION of geometries

Parameters:

wkt -

Returns:

getWKTQuery

public static String getWKTQuery(String spatialField,
                 String wkt,
                 boolean negated)

Build up a WKT query. When a geometry collection is provided this is coverted into multiple queries using boolean logic.

Parameters:

spatialField - The SOLR field that is being used to search WKT

wkt - The source WKT value

negated - Whether or not the query should be negated this effects logic operator used

Returns: