UK Grid Ref

Grid Ref is a simple application that shows your current location in the OSGB National Grid Refernce format.

Mapping and UK government agencies and emergency services still rely heavily on Grid References.

The iPhone 4, 3GS, 3G and iPad 3G contain a GPS receiver which natively uses the WGS84 Latitude and Longitude cooridinate to represent points anywhere on the globe.

The iPhone also makes use of other sources of location information from the Skyhook Wireless system, either the location of mobile phone masts or WiFi Access Points, while these services can give a position that might be good enough to find the nearest cinema or resturant they are not converted to a Grid Reference unless they are accurate to less than 150 metres.

The Grid Ref Application will allow you to obtain your current location accurately without having to carry a GPS or a Sat Nav around with you.

Although this Application will run on an iPod Touch, a first generation iPhone and an iPad (WiFi) it is really intended for the A-GPS equipped iPhone 3G or later and iPad 3G to give accurate locations.

To provide a useful grid reference you really need to have a clear view of the sky for the A-GPS receiver to get the signals from more than two satellites, it is unikely to provide a good fix in a heavily built up area or indoors.

The iPhone 4 and iPad 3G contain an faster Broadcom GPS chip which is significanly better than the iPhone 3G and 3GS and can quickly yield locations as accurate as 5m.