Gebhard Merk, aka Geby, works for Schällibaum AG, one of Switzerland’s leading civil engineering, architecture and geomatics companies. Geby has used UAVs to supplement the firm’s terrestrial geodata for over five years, so he has lots to say about the value drones can bring. Waypoint caught up with him at his office in Wattwil.
1. Hello Geby. Why don’t you tell us a little about your journey into the world of drones. When, how and why did Schällibaum first start using this technology?
Our company, Schällibaum AG, has been dealing with drones since 2012. The pioneering spirit is deeply anchored in our family business and for more than 50 years we have lived this spirit in the field of civil engineering, architecture and geomatics.
As such, new technologies and process flows form an important part of our company, specifically in the design, development, planning and realisation of infrastructure projects, industrial buildings and real estate. In order to implement these projects optimally and efficiently, our surveying and geomatics department accompanies, and provides, architects, planners and engineers with geodata from the outset.
With the introduction of drone technology … we have experienced a quantum leap in our high-resolution geodata collection
The collection, administration and output of geodata is a core task of our surveying team. With the introduction of drone technology into our company more than six years ago, we have experienced a quantum leap in our high-resolution geodata collection.
The combination of small and medium-sized UAVs with sensors from the photogrammetry and laser scanning sectors allows us to efficiently record topography and infrastructure projects with an unprecedented density of information.
Drone technology supplements our surveying equipment, from conventional tachymetry and GNSS measurement through to laser scanning. In addition to capturing 3D geometries from the air, the inspection and monitoring of infrastructure projects through to natural hazards is another important component of our UAV mapping division. We’ve found drones, together with photogrammetry and computer vision software, are an economic and reliable method of quantitatively and qualitatively analysing and evaluating infrastructure.
2. Tell us about one of your favorite or most challenging drone projects. Where and what was it? What made it stand out? What did you learn?
One of our most challenging drone projects to date was the inspection of three bridge segments in a densely populated urban area on the outskirts of Zurich.
This job involved the qualitative inspection of the entire bottom view of the bridge, including all the pillars of the railway viaduct, which we carried out on behalf of Swiss Federal Railways. The reason for this work was to prove the bridge’s condition prior to two large-scale construction projects that were due to take place in the immediate vicinity of the bridge. This task consisted of examining the entire concrete surface for cracks and localising those cracks that we identified.
On one hand, the narrow conditions and the position of the bridge were themselves challenging; located in the middle of an urban district, with the bridge crossing a large street and a tram line that runs parallel to nearby buildings.
The narrow conditions and the position of the bridge were themselves challenging; located in the middle of an urban district, with the bridge crossing a large street and a tram line
There is also a civil and military airfield near the bridge. This meant we needed to gain special flight permits for our drone flights, which we had to register every day at the airfield’s control tower.
Another challenge was the season—our field work had to be completed in January in very icy temperatures of between zero and minus ten degrees C [14-32 °F]. The light conditions at this time of the year also made recording images difficult. So, to be able to produce reasonable flight times with the drones, special arrangements had to be made for the batteries before the flights; the batteries were pre-heated.
During this bridge inspection, we produced more than 6,000 images in total, from the air and from the ground. These were photogrammetrically evaluated and used to create individual orthophotos of the different bridge sections. The cracks were subsequently digitised into the orthophotos and the 3D model of the bridge, and referenced in the Swiss coordinate system.
3. What impact would you say drone technology has had on your working life?
Drone technology has greatly altered, and improved, our qualitative and quantitative surveys and inspections.
Our data recording time in the field has been reduced several times over
Above all, our data recording time in the field has been reduced several times over; earlier conventional methods required much more time. The extreme density of information that can be captured with this technology has also been a quantum leap.
Of course, the extremely high volume of data produced by the drones represents a major challenge. So in this respect, new problems arise, which now have to be solved with new approaches and evaluation algorithms.
4. What kind of role do you see drone technology playing in the future for companies such as Schällibaum? Can you imagine what your working life might look several years down the line?
Drone technology has already become an integral part of our business. I can see that future research and development work in the field of computer vision and artificial intelligence will make unmanned aerial systems even better and provide an even more efficient method of inspecting infrastructure, more systematically, and with higher security.
5. If you could give 3 tips to a budding dronepreneur of the future, what would they be?
- A good flight plan means a safe flight.
- Make sure you comply with legal requirements when flying your drones, so that UAV businesses can continue to exist in the future.
- Keep learning—ongoing flight training will only help increase your safety when flying.
Wonderful, thank you Geby.
Of course, you’re welcome.
Industries served: civil engineering, architecture, geomatic services
Drones: senseFly eBee RTK, senseFly albris, Asctec Falcon 8
Software: Agisoft Photoscan, Pix4Dmapper Pro
Avg. flights per month: 20
Total flight hours: 233 (over 1,400 flights)
Dream robot: a personal flying Tesla robot