Drones or Unmanned Aerial Vehicles (UAVs) are small aircraft guided by remote control or computer. They are mainly used for taking aerial photos or acquiring LiDAR data with accuracy and speed in difficult-to-access areas. In engineering, they can also be used for inspecting dams, assessing foundation cracks and areas affected by landslides. Some of the key benefits of using drones in engineering projects are:
- Safer access to sites and structures, by avoiding hazards such as working at heights, or working over water or along steep slopes;
- Faster and cost-effective data acquisition, especially over large sites and for repeated surveys;
- Easy integration with LiDAR data and input to GIS and CAD software.
Drones have cameras capable of taking photos from multiple angles. Photos obtained during a drone flight can be processed using specialty photogrammetry software to create millions of data points for generating 3D models and high-resolution orthophoto mosaics. An orthophoto mosaic is a series of individual photos which are systematically georeferenced to form a new composite image. Commercial grade drones are available with LiDAR collection units which are able to collect highly accurate 3D point data.
Most importantly, drones help to improve safety by reducing the need for people to climb structures and walk along hazardous terrain. Accessing remote locations and crossing obstacles also becomes much easier.
Drone Use at KCB
At KCB, we use a Phantom 4 Pro drone, which has four rotors and a sophisticated high-resolution camera system.
Our engineers recently used a drone for a slope stabilization project along a river in British Columbia. Aerial photography was collected using a drone flying in a pre-planned flight grid 90 m above the river. The images were processed into a georeferenced 3D model using surveyed ground control points and photogrammetry software. The 3D model was used to generate topographic contours for analysing the river and producing a hydraulic model.
In another project, we used drone photography to inspect a landslide next to a highway. We used an orthophoto mosaic to map surficial features of the landslide.
The landslide formed a high cliff above the river, with an unstable slope marred by cracks and uprooted trees. Using the drone, our engineers surveyed the site without having to put themselves in harm’s way.
Our team has been able to take thousands of aerial images by drone in just a few months. This has enhanced our engineering practice by efficiently creating 3D topographic models and orthophoto mosaics for input into our design and recommendations. In the past, this would have taken much longer using more expensive acquisition methods by helicopter or small aircraft.
Drone Use Regulations
In Canada, Transport Canada’s regulations apply when operating drones for “non-recreational” or commercial use. Their website includes important information including how to get permission for operating a drone, the locations of “no drone zones”, and approved drone flight schools for training drone operators.
For commercial drone use, a Special Flight Operations Certificate (SFOC) is required from Transport Canada. This applies to all UAVs used for work or research, no matter the size or weight of the drone.
For drone regulations in the U.S., visit the Federal Aviation Administration’s Unmanned Aircraft Systems site.