Land survey and GPS for surveyors

Land Survey Control Stations

The Isle of Man Government, in conjunction with the Ordnance Survey of Great Britain, has established an active Global Navigation Satellite System (GNSS) receiver on the Isle of Man. This receiver is incorporated into the Leica Geosystems SmartNet service, covering the whole of Great Britain and Ireland. It is situated at the Isle of Man Airport (IOMS). IOMS is also included in OS Net, the Ordnance Survey network of GNSS base stations. 

In August 2002 the Ordnance Survey released a new definitive co-ordinate transformation to link GNSS observations to the map reference system used for the Isle of Man (OSGB36). The transformations (OSTN02 and OSGM02) established a new datum for the Isle of Man, called Douglas02. This has since been improved to OSTN15 with the coordinates changing slightly from OSTN02.

Active station and transformation information is available free of charge on the Ordnance Survey website.

All producers of surveyed plans and information are encouraged to use the Douglas02 datum wherever possible. This is of particular importance as the difference from the old datum is not constant across the Island and can be in the order of several centimetres. The use of old Ordnance Survey benchmarks is not recommended.

The Survey Section of the Department of Infrastructure’s Operations Division is establishing a database of Survey Control Stations on the Isle of Man. These take the form of points positioned by GNSS and are transformed onto the new datum Douglas02. They are available for use by those undertaking survey operations and details can be provided by the Survey Section. Some of the Control Stations have been positioned as part of topographical survey projects and consequently are on private land.

In addition, Stations can be positioned on request for specific projects. The current rate is £100 per Station.

The information sheet provided gives more details on the background and operation of the Survey Section.