Latitude measures a location’s angular position north or south of the equator. In geospatial SQL, it appears with longitude when coordinates are transformed to SRID 4326, the GPS-style Earth coordinate system. section 10.5.1
Use latitude when converting, extracting, or publishing geographic coordinates:
- Transform geometry with ST_Transform(way, 4326) to obtain longitude and latitude. section 10.5.1
- Extract latitude with ST_Y; longitude is extracted with ST_X. section 10.5.1
- Pass latitude as the mlat parameter when generating an OpenStreetMap URL. section 10.5.1
Mapping Tampa’s latitude
After transforming Tampa’s point, the result is POINT(-82.458444 27.947759499952074): longitude comes first, followed by latitude. An OpenStreetMap URL uses mlat=27.947759499952074 and mlon=-82.458444 to place the marker. section 10.5.1
Listing 10.12 Transforming coordinates to latitude and longitude
SELECT name, ST_AsText(ST_Transform(way, 4326)) AS coordinates FROM florida.planet_osm_point WHERE name = 'Tampa' and place = 'city';
See the executable transformation that converts a stored point into longitude-and-latitude coordinates. section 10.5.1
