Photogrammetry is the science of making precise measurements from photographs.  This is achieved through the use of overlapping imagery; where the same feature can be seen from two perspectives it is possible to calculate measurements. This principle is the same as our ability to judge distance and depth using our eyes as we see the same object from each eye. Our photogrammetric surveys are taken at low altitudes (less than 120m) allowing us to capture extremely high resolution overlapping imagery which we can process into very accurate and fully georeferenced elevation models. The result is similar to that produced by laser scans but at a fraction of the cost.

For aerial applications, a series of overlapping images must be collected both in the direction of flight (known as end lap, or vertical overlap) and between adjacent flight lines (known as side lap, or horizontal overlap). The percentage of overlap will vary based on terrain variation and the client’s needs, such as accuracy requirements and ground coverage. We use automated flight control software to ensure the accuracy of our flight plans in getting an exact level of overlap.  Larger levels of overlap are capable of producing greater levels of accuracy, but require more photographs to be taken and more lines of flight therefore increasing the flight time. Typical levels of overlap are a minimum of 60% end lap and 30% side lap, but these can be increased to 80% in both directions where required. 

Please contact us to find out more about our survey experience and to discuss your requirements on 01444 401840

Photomosaics & Digital Elevation Models

Using photogrammetry we produce both imagery (photomosaics) and digital elevation models - click on the links to find out more about these

We are able produce photographs at a far higher resolution than can typically be achieved with t
raditional aircraft based aerial surveys. These detailed images can be used to create high resolution DEMs that outclass those produced using traditional aircraft, in terms of both resolution and accuracy. Typically we offer accuracies down to 30mm RMSE. Read more about the accuracy of UAV surveys

 We can produce both digital terrain models and digital surface models depending on your requirements. By combining the imagery with the elevation models we are also able to produce orthorectified images (orthophotos) 

 Please contact us to find out more about our survey experience and to discuss your requirements on 01444 401840