Imagery + Photogrammetry

Terralink International offers a complete range of photogrammetric services. From managing the acquisition of aerial photography, through aerial triangulation and stereo compilation, to the production of digital terrain models and orthophotographs, Terralink International’s imagery unit has the expertise, equipment and capacity to deliver.

What is photogrammetry?

Photogrammetry is the science of taking measurements from photographs, usually aerial or satellite photos. By viewing a pair of overlapping images in stereo (ie one for each eye) a height measurement can be obtained. Ground control points gathered on site are referenced to each photo providing scale for the x and y co-ordinates.

What is an orthophotograph?

An orthophoto combines the visual advantages of a photo with the accuracy of a map. Starting with an aerial or satellite photo, distortions caused by the curvature of the earth, camera tilt and terrain relief are removed through the process of orthorectification. The completed orthophotos are geographically referenced and provide a key data layer in a Geographic Information System (GIS).

Imagine a photo of your farm or forestry holding that you can measure from. Making calculations such as how much fertiliser to use, how many pruning staff to employ becomes much simpler when you can see the blocks that you are measuring. For environmental planning orthophotos are invaluable providing context to geographical data.

The Waikato Regional Aerial Photography Syndicate commissioned Terralink International to acquire and process aerial photography for the Waikato region. Find out how it was done in the WRAPS case study.

Terralink International uses orthophotos derived from aerial and satellite imagery to create detailed topographic maps, allowing accurate portrayal of an area without having been there. Read how this is done in our Australian Federal Mapping case study.

For more information on the use of orthophotos in farming check out Farmbase, our digital orthophoto product ready to load into several popular farm management software packages.