Os grid ref to lat long converter

TG represents a 10m box with its south-west origin An alternative way of expressing OS Grid References is as all-numeric eastings and northings, usually in metres. As square TG is six squares across, three squares up within the grid, grid reference TG can also be expressed as , As the surface of the earth is curved, and maps are flat, mapping involves a projection of the ellipsoidal curved surface onto a plane flat surface.

The Ordnance Survey grid is a transverse Mercator projection. Historically, cartographers worked at finding the ellipsoid which provided the closest mapping to the local geoid. The geoid is equivalent to the local mean-sea-level or its equivalent in land-locked locales , and is determined by the local force of gravity.

These ellipsoids were then fixed to local datums fixed reference frames established through cartographic surveys. As square TG is six squares across, three squares up within the grid, grid reference TG can also be expressed as , Beware that eastings and northings can be used either as a grid reference identifying a grid square , or as a coordinate identifying a point.

In this example, the coordinate representing the centre of grid reference TG would be , It is often ambiguous whether eastings and northings are being used as grid references or as coordinates.

The JavaScript implementation should be quite simple to translate to other languages, if required. OSGridConverter 0. Latest version Released: Jul 31, Navigation Project description Release history Download files. Project links Homepage. Statistics View statistics for this project via Libraries. Maintainers jdstmporter. Tags A list of strings: names of the standing mapping Data that the package is aware of and can convert between. Project details Project links Homepage.

Download files Download the file for your platform. Files for OSGridConverter, version 0. The name of the datum used in the conversion; default is WGS84 , referring to the standard datum used by Ordnance Survey. The point to be converted.

The name of the mapping datum used in the conversion; default is WGS84 , referring to the standard datum used by Ordnance Survey. File type Source.