Given the technology and the flight regulations and rules in most countries, the most economical way to benefit from UAV technology in the next year or two is to combine it with additional sensors on the ground, believes Optech CEO Donald Carswell
How do you see the UAV space shaping up?
Since regulations vary so much from country to country and the capability expectations are so different, unmanned aerial vehicles will become game changers in ways we are not anticipating right now. For instance, it could be that UAVs may eventually create so much interest in geospatial information that they generate fresh demand for conventional ways of acquiring it, whether it’s satellite or aerial or mobile mapping.
What are Optech’s plans in the UAV space?
We have already entered the fray. Many of the UAVs being developed now are, by conventional standards, of somewhat lower accuracy than what is achievable through other means. At Optech, we are taking a sensor fusion approach, which is also a platform fusion approach. For example, if you want to use the UAV in a particular area but you want to maintain 1 or 2 cm accuracy, the most economical way to do that right now is to do a ground survey with a LiDAR from scanner a single setup. Of course, that is only one vantage point, but you get very good centimetre-level accuracy on the whole thing. Since you will have some shadows, you can use the UAV to collect information from above the area, then combine the two in the Optech workflow, giving precedence in the fusion to the more accurate terrestrial LiDAR data. LiDAR data can in fact be used to control and improve the accuracy of the UAV data to standards that the UAV alone would have a challenge achieving.
There are also additional benefits of such a combined approach. It allows for the UAVs used to be as small as possible, which means it is easier to get the flying permission. You will be in a smaller weight class and there will be fewer restrictions, and yet you get the full benefit of fusing the UAV camera and ground LiDAR results in a common workflow for a single deliverable. As the technology improves, it will make sense to move more to the UAV platform. For now it is important to keep the UAV as small and light as possible so that it can be widely adopted with the minimum of regulation.
So right now, you see UAV as only filling the gaps?
Yes, basically. We also use the UAV camera to apply colour to all the laser points, so that, in a way, it is how you stitch and link the data together. You can clearly see the laser points and the colours that the aerial camera applied to them in the end result, so you know that it is correct. We believe this is a very practical way of doing it because of the dense photo matching from the UAV, which might be anything from 2 to 20 cm accurate. With the terrestrial LiDAR you know your accuracy.
This approach really combines the strengths of the LiDAR for accuracy and of the UAV for area coverage, leveraging two different platforms and integrating them in a single workflow that delivers the best of both worlds.
Does Optech have separate UAV and LiDAR divisions?
Right now we have actually incorporated them as a part of the static tripod scanner division because we think there is a very natural synergy between a tripod scanner and a UAV, both being single operator systems. For example, if you had an open pit mine you were going to survey, you can drive there with both the laser scanner and the UAV in your vehicle. Since it is fully automated, you can get the terrestrial scanner going, and while it runs on its own you can get the UAV out, put its flight plan in, and have it fly at the same time. One person can very easily deploy and use both sensors at one time.
A customer can buy from Optech only the UAV, only the scanner, or the combined kit for the complete solution. Many of our clients already have a scanner so they just need to add the UAV and software. Some of our clients may opt to acquire only the UAV at first, though they may later want to add a scanner for the enhanced capabilities and accuracy. To meet these varied needs, we try to be very flexible in our approach.
As an expert, do you like a combination of the two?
I believe that right now the combination gives the biggest bang for the buck. It makes it as simple as possible to produce good results and gives you the maximum likelihood of getting permission to use it. If you have a UAV that has a 2-metre wingspan, it is going to be extremely difficult to get flying permission. On the other hand, if you are flying a little octocopter weighing only 3-4 kg, permission is either automatic or very readily available. So what is the point in having a large, very capable UAV platform if it takes you weeks to get permission to use it? You are just wasting time and opportunity. Right now, given the state of technology and flight regulations, I believe that for the next year or two the most economical and practical way to benefit from UAV technology when accurate data is needed, is to combine it with additional sensors that are on the ground.
Published in Geospatial World Magazine December 2014 as ‘UAVs are going to be a game changer’