By Pascal Strupler
Over the past year, a new technology product category has emerged that’s cultivating a growing interest among UAV professionals. It’s flying imaging laser scanners that go beyond traditional UAVs for reality capture.
Laser scanning has always been critical for designing and building structures, cities and environments. Yet capturing hard-to-reach places was difficult and the best solution to date has been to rely on drones. However, traditional mapping UAVs are limited in that they often take a top-down perspective while scanning or doing photogrammetry. This limits their ability to accommodate projects that vary in size and scope, or variables including vegetation, cables, and pipes. This results in scans that contain shadows, incomplete textures, or missing details. Also, as the scans create massive amounts of data, transferring and processing the information from a UAV can be tricky
Going beyond traditional drone platforms carrying cameras or laser scanners, the new category of fully integrated flying reality capture systems offers a faster, more streamlined way to build digital twins from the sky. Using both cameras and LiDAR simultaneously while flying, they quickly and accurately capture the exterior features and dimensions of buildings, structures, rooftops, facades, and other environments that would otherwise be dangerous or inaccessible for humans. They can also make the scan data immediately available via storage in the cloud, which reduces the risk of human error in data transfer.
Designed for Reality Capture
With traditional UAV solutions, the design is led by the necessary features required to support flying. Using a UAV for reality capture often requires a bolt on sensor that’s externally attached as well as a separate remote control device. This creates a larger system and complications when it comes to maneuvering the UAV for reality capture. In flying laser scanners, the design is driven by reality capture, which is built into the system yet also has a completely integrated flight system. True to reality capture, flying laser scanners provide a preview of a live point cloud so the user can see what’s been scanned. This saves time by being able to make adjustments on the fly as opposed to discovering issues after leaving the site.
The combination of live reality capture, data and flight control with obstacle avoidance provides autonomous navigation and scanning. Efficiency gains are realized through autonomous scanning in complex environments, a faster capture process and a comprehensive workflow that can support datasets from other sources.
Still, flying laser scanners aren’t a replacement for traditional mapping UAVs. In some instances, it makes sense to use a mapping UAV over a flying laser scanner. For example, if the area is simple, flat and can be scanned from the top down without the risk of scan shadows, traditional UAVs equipped with photogrammetry or laser profilers are more efficient. Also, if the scanning is expected to require a long flight time and the area is not complex. Additionally, if it requires high resolution photos or textures of the object such as a detailed visual inspection, a flying laser scanner is not the right product for the job.
Examples where a UAV is ideal include scanning an open-pit mine to create a 3D model, capturing the surface model of a landscape, or scanning a dam or a powerline mast for visual inspection.
Where Flying Laser Scanners are Being Used
Professionals in architecture/engineering/construction (AEC), Building Information Modeling (BIM), and UAV mapping and surveying are adding flying laser scanners to their workflows. Additionally, there is an increased use among professionals in media and entertainment responsible for location scouting, set design, and construction, and creating virtual realities. Flying laser scanners are picking up where there is a great need for a clear view of geometrical configurations that require 3D views.
While flying laser scanners are different from more traditional mapping UAVs, they do require a drone pilot license. In some instances, the owner may be required to register the device and get permission for each mission.
That said, flying imaging laser scanners with obstacle avoidance have the potential to usher in the next generation of flight safety technology, making them an attractive option for drone pilots regardless of their level of experience with flying UAVs. They also save time and resources previously allocated to accurately capture hard-to-reach or dangerous areas. Cost savings span staffing, investments in alternative technologies, and potential insurance and safety risks.
Overall, these machines represent an exciting new frontier for agile aerial reality capture.