How Surveyors use drones

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.

Frequently Asked Questions

How do drones improve the accuracy of survey maps?

Drones capture hundreds of high-resolution photos over a site, which are processed using photogrammetry to create precise contour maps and detailed orthophotos.

Can drone surveys replace traditional surveying methods?

Drones are an additional tool, not a replacement. They are ideal for capturing up-to-date images quickly, but some projects still require traditional survey techniques for accuracy.

Are there limitations to using drones on survey sites?

Yes, drones have limitations including battery life, weather conditions, and obstacles like birds or trees, and they may not add value for every project.

What are the main benefits of using drones for surveying?

Drones provide current, high-quality aerial imagery, enable faster data collection, and improve site visualization while supporting accurate planning and design decisions.