When you have a lot of scanning to do in a short period of time
A typical onsite long range 3D scanning project involves a single scanning team, which includes one or two technicians, the 3D scanning instrument of choice such as a Leica RTC or Faro Focus, and the various required accessories such as tripods and targets. The team then scans for as many days as is needed to complete the project. Many scans can be taken in a day, so usually this is no problem. But occasionally there are situations where one scanning team is not enough. Bring in the “swarm scan”.
What does swarm scanning mean?
Swarm 3D scanning is a term used to describe a process whereby multiple scanning teams and instruments are applied to the same area at once, attacking the site with a “swarm” of scanners to capture the environment as quickly as possible. The 3D scanning instruments need not be the same type. In fact it can be of great benefit to use a mixture of different types of scanners to take advantage of their strengths. Drones, long range P-series Leica scanners for large areas, RTC360 for plant areas and BLK360 for office buildings. But the key here is that they are all being deployed simultaneously in order to minimize the time that the scan takes.
Why do it?
Swarm 3D laser scanning may be employed in situations where there is a “turnaroud” such as when a plant shuts down for a short period to do maintenance. In these situations there is a strict time frame in which work can be done, so the 3D laser scanning efforts must be completed within that time slot. Another example would be a hotel that is shut down for renovation. It is obviously very costly for a hotel to clear all the rooms of guests, so they want to keep this period as short as possible. Swarm scanning provides the absolute fastest way to scan a facility. When you think about it, if one had 500 scanners and 500 technicians, it would be possible to scan a 500 room hotel in 10 minutes. Of course, this would never happen in real life but it just illustrates that the sky is the limit if enough resources are available.
How it works
Step 1 for swarm 3D laser scanning: buy a lot of scanners. Step 2: Assemble a team of trained 3D scanning technicians. Step 3: Create the swarm plan. Planning is everything. It is important to segregate the scanning areas so that each scanner/technician knows which areas are theirs and fully scans their area without crossing too far into another’s area. This is a balancing act because there must be some overlap between areas to ensure good coverage and registration. Usually the scan areas are obvious choices based on certain features such as buildings or well-defined sections of a plant. But staying organized will pay off later when it comes time to register them together.
Then for the fun part: registration
After having done a swarm 3D laser scan, you end up with a virtual cornucopia of scans to put together. Scan registration can be challenging enough with a single scanner, so scan registratino with swarm scans is going to be all the more challenging. But with proper care and organization, it can go smoothly. Ideally the individual scans are segregated by obvious, well-defined boundaries and scans from the individual instruments can be registered separately before combining all together. It is possible for multiple scanners to attack the same area, and in that case registration can be a little more complex, involving bringing the scans into a single pool before registration. Survey control is an excellent way to maintain organization. Using control points, scans from the different instruments can be aligned to the survey control which automatically aligns them together as a whole.
What is different now
What has changed to enable the idea of swarm 3D laser scanning? The plethora of 3D scanning instruments available for one, and the ease of being able to deploy them. Also, the ability of software such as Autodesk ReCap to connect to multiple scanners at once.
Is it really a thing?
Swarm 3D laser scanning is an interesting concept, and there certainly are occasions when multiple scanners and teams need to be utilized, but using the term “swarm” might be a stretch. It is a nice buzzword though. Perhaps some day there will be hundreds of robotic 3D scanners that migrate around a site, automatically scanning everything they see and controlled by a central AI. That would be a true swarm. But one thing we can agree on, is that new ways to do 3D laser scanning are always welcomed.