Share | 02/17/2020
We sat down with Romain Kirchhoff, Head of Operations at Sensat, to talk about their use of drone technology to help with its mission of digitizing the world. Romain has an MSc in Management, Technology and Entrepreneurship from the Ecole polytechnique fédérale de Lausanne (EPFL) and the Hong Kong University of Science and Technology (HKUST).
Sensat is a startup working to digitize the physical world. Essentially, the real world is offline; it cannot connect with computers or other devices. This is a huge hurdle when developing Artificial Intelligence for real-world use, something that we believe can help us to live our lives more sustainably.
We do this by creating digital twins, or digital representations of real-world locations. We then infuse real time data sets from a variety of sources. The result is an accurate, digital and up to date copy of the real world in a machine-readable format. Drones are an important part of this process, as we use a mixture of drone imagery and LiDAR data (laser scanner) to generate highly accurate digital replicas for our clients in Infrastructure and AEC.
We have an incredible team based in London and recently raised $10 million for our Series A which was led by Tencent!
As a young startup, we started with drone technology—and that’s all we started with. We have learned how to achieve high levels of detail in our photogrammetry, but there is always a tradeoff between detail and the area coverage.
We are now extending that photogrammetry knowledge and expertise into terrestrial laser scans, UAV LiDAR, plane photogrammetry, plane LiDAR, and satellite photogrammetry. Thanks to the drone industry, we have been able to create our company.
We did investigate traditional methods; looking at things like terrestrial scans, as well as aerial scans using a plane or helicopter. We found that terrestrial scans couldn’t provide the large-area coverage we needed, and that helicopters could not provide enough detail compared to ground-based surveys. They’re also expensive and weather-permitting.
Drones unlocked the middle ground between those two methods, providing the accuracy and coverage we needed to work within the infrastructure sector.
We’ve used eBee fixed-wing drones since the beginning, but we also used quadcopters. Through our three-year journey, we have assessed many different quadcopters and fixed-wing drones, even a few VTOLs. When assessing a drone provider and model to operate, the deciding factor we focus on the most is reliability.
We’re thankful for eBee drones because we know they are the most reliable on the market. That’s been crucial from a safety perspective and for generating consistent, high quality data.
We started with the eBee RTK. Then, the eBee Plus. Most recently, we acquired two eBee X’s which have been fantastic. We’re also very happy with the quality of the eBee series S.O.D.A. 3D sensor. It’s great because it has a gimbal that ensures all images are perfectly nadir. The option to have oblique images is also a key differentiator for mapping areas with complex structures such as cities. One of the key things that’s helped us adopt and implement drone technology are our people internally.
We are using a mix of capture methods ranging from terrestrial scanning to satellite imagery.
If we select the drone as the capture method for a specific project, we will follow a general workflow: Step one is to assess all relevant risks and mitigate against them until we and the client are satisfied with the mitigation in place. Step two is to go on site and capture the imagery. The main focus is on safety and we have integrated several features to ‘see and be seen’ by other airspace users and local authorities. Step three is to generate a single 2D map and a 3D model from these pictures. The Quality Assessment of the raw images and the outputs is another key step to ensure we provide the best data to our clients.
The final output and file format will be tailored to the client needs which can range from earthwork calculation and progress monitoring to 3D topographic CAD and BIM.
Finally, instead of delivering a 15GB LAS file that the client can’t even open in their construction software, like Autodesk (it will crash); we deliver the 3D model and 2D map in our intuitive environment Mapp accessible online to visualize and interact with the datasets. While simple 2D and 3D measurements or annotations are available on Mapp, the client can also crop an area of interest and open it in their own software. We can also ‘augment’ the digital twin by integrating BIM designs or live feeds into Mapp such as IoT sensors, CCTV cameras, and so on.
We use different processing software like Agisoft, Pix4D or ContextCapture. We’re always testing different technology to make sure we’re using the best processing software out there. Drones unlocked the middle ground between methods, providing the accuracy and coverage we needed to work within the infrastructure sector.
If we compare drones to terrestrial surveys, the benefits of using drones is that they’re more efficient and safer – you don’t need to have boots on the ground when surveying a highway for example.
If we compare drones to traditional aerial surveys like planes or helicopters, we are usually more accurate because we are closer to the object but that depends on many factors like which camera we use and the flight altitude for example. We are also generally cheaper and using drones is more environmentally friendly.
The absolute accuracy we achieve with drone photogrammetry is dependent on many factors including the Ground Sampling Distance (GSD). In general, our GSD is 25 millimeters and our absolute accuracy is within 50 millimeters in the horizontal plane (X and Y), and 75 millimeters in the Z axis. Those numbers are specific to our general operations when we use a 20-megapixel camera like the S.O.D.A 3D, at a 108 meters altitude above ground level, which means that each pixel is 25 millimeters wide.
This level of accuracy is a perfect fit for our large-scale survey. It provides a good enough accuracy while having a manageable file size for the end client. For smaller surveys we can get sub-centimeter accuracy if required by using more advanced and expensive hardware.
Impacted is not the right word. Thanks to the drone industry, we have been able to create our company. That was a massive win for us because it has helped us enter this new market between traditional terrestrial and aerial scanning. It’s provided us the ability to deliver projects to early adopters within the industry. When I look around me, I can tell you we have achieved some great milestones with drones, and it is only the beginning!
Most of the challenges we’ve had have been on the regulatory side. Because it’s a new technology evolving rapidly, regulations are still changing and improving. It’s not like passing your driving license and you can drive anywhere in the world.
We have been pushing the envelope by collaborating with the government’s Pathfinder program and flying beyond visual line of sight to assess what can be achieved while maintaining a high level of safety.
We’re thankful because eBee drones are the most reliable and safe on the market. That’s been crucial from a safety and regulatory perspective while generating consistent, high-quality data.
Another challenge is the weather. Coming from Switzerland, the UK is a little bit… different. For example, in one day, you can have a clear blue sky, then some thunderstorms!
We need to have an understanding of the weather to assess when we’ll have the next clear window on a specific location to plan our operations accordingly.
We are working on a wide array of projects at the moment including highways, railways, housing development and even airports! We are also working on our range of capture method to deliver the highest quality possible.
Unfortunately, I can’t talk too much about it at the moment but be sure to stay tuned, it is just the beginning!
Sign up to receive updates directly to your inbox.
