Articles

How Surveyors use drones

17 May 2018

Last month, I talked about the Civil Aviation rules for drone operators. Surveyors along with many other professions are recognizing the added value that is obtained by the use of drones. The survey profession have utilized aerial photography for many years to obtain high quality up to date images of sites, and to also use photogrammetric techniques to derive good quality contour maps. This is achieved by the use of overlapping images taken from different positions, to determine changes in height.

These techniques are now utilized by flying drones in a regular pattern over sites of interest and capturing hundreds of high quality photos during the flight. These images are then downloaded into appropriate software which uses photogrammetric techniques to derive accurate contour plans.

In addition, the photos can be combined into one very high quality orthophoto, which produces extremely good details of the site. The key benefits being that the photos are current, and that the quality is very high.

Like all techniques, there are limitations, and there are many circumstances where the use of drones adds no value for the client. And there are always dangers to watch out for, like seagulls and hawks who are too inquisitive, and batteries that run out before you are expecting them to. However they are an additional resource which is likely to see increasing use over time.