Name

ST_Distance_Sphere — Returns minimum distance in meters between two lon/lat geometries. Uses a spherical earth and radius of 6370986 meters. Faster than ST_Distance_Spheroid ST_Distance_Spheroid, but less accurate. PostGIS versions prior to 1.5 only implemented for points.

Synopsis

float ST_Distance_Sphere(geometry geomlonlatA, geometry geomlonlatB);

Description

Returns minimum distance in meters between two lon/lat points. Uses a spherical earth and radius of 6370986 meters. Faster than ST_Distance_Spheroid, but less accurate. PostGIS Versions prior to 1.5 only implemented for points.

[Note]

This function currently does not look at the SRID of a geometry and will always assume its in WGS 84 long lat. Prior versions of this function only support points.

Availability: 1.5 - support for other geometry types besides points was introduced. Prior versions only work with points.

Examples

SELECT round(CAST(ST_Distance_Sphere(ST_Centroid(the_geom), ST_GeomFromText('POINT(-118 38)',4326)) As numeric),2) As dist_meters,
round(CAST(ST_Distance(ST_Transform(ST_Centroid(the_geom),32611),
		ST_Transform(ST_GeomFromText('POINT(-118 38)', 4326),32611)) As numeric),2) As dist_utm11_meters,
round(CAST(ST_Distance(ST_Centroid(the_geom), ST_GeomFromText('POINT(-118 38)', 4326)) As numeric),5) As dist_degrees,
round(CAST(ST_Distance(ST_Transform(the_geom,32611),
		ST_Transform(ST_GeomFromText('POINT(-118 38)', 4326),32611)) As numeric),2) As min_dist_line_point_meters
FROM
	(SELECT ST_GeomFromText('LINESTRING(-118.584 38.374,-118.583 38.5)', 4326) As the_geom) as foo;
	 dist_meters | dist_utm11_meters | dist_degrees | min_dist_line_point_meters
	-------------+-------------------+--------------+----------------------------
		70424.47 |          70438.00 |      0.72900 |                   65871.18

	

See Also

ST_Distance, ST_Distance_Spheroid