 The good news is my presentation will even address the using drones in Bessemetric, Bessemetric LiDAR. I'm David, I'm from Skyobility. Skyobility is a drone service company based in Austria. We are doing mainly jobs over the whole German region and what makes us special is that we started in 2020 in using this drone Bessemetric LiDAR system from Riegel, which is still really big and it is not, to be honest, really typical for a drone. As I said, Skyobility is a drone service supplier. We have many different drones in our company. We start with 250 grams up to 42 kilograms. We use it in different fields, but we have a deep focus on surveying and inspection tasks. As you can see on the mapping side, we are using different laser scanning systems on the green light channel, on the red light channel. We have it on the terrestrial side, so we have often projects where we need a combination of all the systems. On the other side, we are using our drones for inspection stuffs and we do a lot of research activities around all this to really have a good result in the end of that what we are doing. This is how Skyobility looks like, so as you can see there are different platforms and since the laser scanners become bigger, more powerful, you have to use bigger drones. Sometimes there is the need to even jump on other platforms. As you can see, there is even the use of boats, the use of cars. I think it's really familiar to you how you can use those different sensors. On the data side, we address big point clouds, point clouds coming from different sensor systems. We have to combine them. We have to be aware of that we have a high accuracy on our data, so we do it mainly for survey and it is always a little bit a challenge of us to bring all those information together. But come today to the point of my presentation, what you can see here is the collection of the best symmetric data was made in Austria. It is the Drown River. The whole project was done over 60 kilometers, but you can see here is just a small place out of this rendering where we have done the collection with this VQ840G laser scanning system and on the dry land there was even the collection done with a red light laser scanning system. Those data sets were combined and as you can see you have a really high, accurate, high detailed information of this area that you really exactly know how is the topographic situation in this area. As I said in the beginning, we are using the VQ840G. It's a laser scanning system introduced by Regal in 2020. It is a really not lightweight scanner for the Drowns because it has still 11 kilograms when you put it on a drone and when you consider when you want to use smaller drones in the range of 25 kilogram, there is not much air between that that you can really bring it efficient to the air. The sensor system is mainly built for fly tides up to 300 meters above the water level so the energy it can you deliver on the water surface is built that way that it allows you to see under the water 2 to 2.5 more than you can see in the water so it is a really a question of the durability of the water, how is the quality of the water and what is the flight head and even the parameter set you are using on the scanner system. The way the scanner system is collecting the data is really specific so as you can see it is not a linear scanner it's a scanner system is rotating in a circular way that opens up a strip width of 20 plus minus 20 degree that leads to a strip width in flying of 120 meter this is typical for drone usage of 86 meters so the collecting with the scanner system is not the deficient like other scanner systems who has a broader width but this front-looking and back-looking situation of this scanner is needed to really can penetrate the water very well. By scalability the scanner system is mainly used on different drone systems right now we address mainly in 12S lipo system that means that it is possible to go with the trains planes with the drones up to 20 to 25 minutes per flight normally when you address just the shallow water area or just the river section it is more than enough because right now as the regulations are really strict this is mainly allowed to just go in the range of visual line of sight mainly in Europe. As you can see on this weight calculation it is really hard to fit under this 25 regulations rule so there is the need for specific authority that you are allowed to fly with those drones you have really to consider when you use these kind of scanners for these mapping applications. The flight planning is really important because as I said the flight strip is not that broad and you really want to address the flight way in a in a method that the laser scanner can really well penetrate into the water. What is even really important that you have a really good information about how is the water high of the water level because the distance from the scanner to the water level is really telling you how good the penetration was after the flight. How is it done? The laser scanner imposes a green light laser beam into the water and you have different acres coming back from the first water surface is a reflection then it penetrates into the water there is a reflection that means there is a change in the direction and even in the speed of the light under the water and you will get another echo coming from the ground under the water. What can I say to the point cloud quality you can expect out of those laser scanners it is that way that the range precision of those laser scanners will give you a curiesis up to 50 millimeter in precision but as you may know it all depends on the flight path of the correct interpretation where you have flown and even of the orientation of the scanner systems and when you do it all properly and you give enough time even and do the reflection under the water correct you can expect a curiesis under the water even under 5 centimeters. What is a little bit a minus on this scanner system is the point density dispersion as you can see on the left hand side you always had on the borders of the strip a really high dense point cloud normally you can expect out of the scanner systems point density this in the mid at least over 60 points per square meter but on the border it becomes really really high even out of the extraction you have to expect point clouds that are really really noisy so you have to be really careful in classification and deleting those noise points but when you do it really well as you can see on this section of the river you will get a really nicely interpretation of the river bait even under vegetation. There is always the question how good it works in depth so as I said it really depends on the turbidity on the water and even on the water quality so when you have good conditions we have seen in the past data collected up to 14 meters under the water surface but when you have not that good condition like you can see here on whitewater places the penetration is not that good but you will find as well some nice points what will interpretate the correct topographic situation of this whitewater place. Now I will show you a big project we have done in the past I think it is really worth to see it what you can see here is the Fjordstedtase in Switzerland this whole lake is around about 120 square kilometers and the shallow water area was collected over 14 days as you can see on these green strips where I have this detail here for the deeper sections there was a echosonar data here so we have to combine our green light laser scanning data with the sonar data what you can see is the topographic information in green the green light data includes the sonar data and there is even some darker green areas where there is still no data available because it was to death for the green light laser for this project we have seen data up to 12 meters so there was the goal to come into five meters in the water so we were really lucky on that side that we have a really high overlapping area between those data sets yeah what we can see here is that the information under the water is really worth to see it was really a stunning for us as well to see how it really looks under the water and I want to share these pictures with you here right now to see how it can works over such a big project in the beginning I was showing you as well this river situation I have to come to the end okay as you can see you can collect the whole area in a high information so that you have a accurate interpretation of the situations another project we have done on the river side so just to give you an idea what can be done with such of scanners what you can see on the right hand side is that even under the trees the collection is really good of the topographic information one leg at the left and one nice rendering as well from my Alpine River in the end of my presentation you can find me on the booth of Riegel in hole 5 thank you very much I hope it was interesting for you I hope I can see you again