An advantageous tool to the DDC team, Geo-Referencing is the term used to describe the method of defining the co-ordinate positions of a particular image file. For example, if the image file is off an aerial photograph or scale plans of some land, then for it to be useful when inserted into CAD and GIS programs, its co-ordinate position and orientation needs to be defined.

The result is when an image is inserted, the co-ordinates of each and every point item match their real life Ordnance Survey Easting’s and Northing’s co-ordinates. This will then allow for new geographical features to be entered at their correct co-ordinates, with these features positioned correctly in relation to the original inserted image.

When digitizing land survey plans or maps, we geo-reference the image file so they can be inserted in CAD or GIS programs. Typically we would save the image file as a ‘.tif’ file and create a ‘.tfw’ file to define the images insertion co-ordinates and orientation.