Aerial Photography is a largely under utilised data source. It has the potential to be used for gathering a wide range of information such as moorland fire damage, woodland classification, habitat classification, road, tracks and paths, at very low cost or as an alternative to an OS base map.

The use of aerial photography poses a number of inherent difficulties which must first be overcome before accurate data can be extracted.

• The camera not pointing directly downwards at the moment the picture was taken resulting in a change of scale across the photograph (a square on the ground might appear as a trapezium)
• Hill tops are closer to the camera than the bottom of valleys and so are captured at a larger scale (i.e. scale varies across the photograph)
• Land of different heights at the same distance from the centre of the photograph are displaced away from the photo centre to different degrees (commonly called relief displacement)

To transfer data from a photograph to a map these distortions must be removed. There are a number of simplified approaches which produce a ‘best fit’, but only one rigorous solution - OrthoPhoto rectification.

OrthoPhotos register perfectly to Ordnance Survey LandLine data and mosaic together to produce seamless photo base maps thus opening up a whole new environmental data source.

Uses Include:

• Habitat Classification
• Footpath Erosion Mapping
• Map Detail Revision
• Land Use Monitoring
• Woodland Classification
• Development Planning
• Archaeological Feature Mapping
• Moorland Fire Damage
• Flood/Wind Impact Assessment

Simple to Use:

1. Scan the photo
2. Locate the calibration marks (fiducials)
3. Identify 5 well defined points on the image (ground control)
4. Enter the ground control coordinates/heights (from map/GPS)
5. Select the DTM (Panorama file)
6. Press 'GO'

Requirements:

System runs on Windows 2000 or Windows XP and the processing amount/speed is processor dependent (ie. faster the processor, the more and quicker photos can be processed)

Prices:

Software prices from £495 but please contact us for more information, or we can offer a full Orthophoto rectification service

Download a leaflet detailing the OrthoPhoto software here (PDF format).