|This site makes extensive use of mapping and positional information, four position systems are deployed, we use Postcodes to link to external mapping services, and display Latitude - Longitude - OS Grid Refs and British National Grid positions on our location pages. This enables us to show how far a specific location is from the sea and other fixed points, and offer accommodation and other information that is "at or near" a specific reference point. Also useful for GPS users.|
planet earth is often depicted with a grid of lines
covering the surface. These are the Latitude and
Longitude lines. Both of these are measured in
degrees, minutes and seconds. Example 52° 55' 56"
The latitude lines (sometimes called parallels) run horizontally around the planet in an east west direction like the equator. The equator is 0° and both South and North poles are 90°. All points in the northern hemisphere have a northern latitude and are denoted with an N and S denotes the southern hemisphere.
The longitude lines (sometimes called meridians) run vertically from the north pole to south pole like the Greenwich prime meridian 0° the reference point for Greenwich Mean Time (GMT). All points east of this are denoted with an E and all points west with a W. They join up in the middle of the pacific ocean at longitude 180°
Some websites use a decimal representation of Latitude and Longitude. i.e 55.5856 or similar
The Ordinance Survey Grid Reference system provides a scale independent method of pin pointing every position in the UK, and has been printed on ordinance survey maps since the 1940's. Example TG 073386
The first two letters specify a single grid square; the first narrows it down to a 500km square, and the second to a 100 km square. This system uses 6 figure grid references to pinpoint a location to within 100 meters. The first three figures provide an easting (073) and the second three the northing (386). The first two digits of each pair define a specific grid line on the map and where they cross a grid point (07,38). The last digits of each pair together represent an imaginary point north and east of this grid point.
|The British National Grid system identifies every point in the UK as an offset from a datum point just south west of the Scilly isles in meters. Example E608060 N338640 Easting and Northing figures represent an cartesian offset point.|