Sky Tech was approached by Ph.D student Rosie Bisset from Edinburgh University School of Geosciences last year to assist with a custom build drone. After a year of bad press for drones and the climate emergency frequently in the news we were motivated to help with a drone mapping project.
Rosie’s glaciology project was to map an area of the Llaca and Shallop glaciers in Peru. Previous studies had shown large reduction in glacier area in the Cordillera Blanca from 1987 to 2010. These glaciers are an important source of water for the area and research had already shown a reduction of fresh water during the dry season.
One part of the study was to examine surface debris depth and how it affected melt rate. A camera drone needed to be flown in a grid pattern to build a 3D model of the surface. A FLIR thermal camera on the drone would also be used to measure surface temperature differences. In particular to draw links between the thickness of the surface debris and elevation changes, surface movement and water pooling.
Custom Build Drones
This was a challenging custom drone project as the equipment needed to be ready and tested in a few weeks. Sky Tech also needed to provide sufficient training for Rosie and her assistant to fly the drone on the glacier. It had to be a simple to use and quick to deploy. There was some hiking to do to the glacier so the drone needed easy to transport in a backpack. The operating conditions for the drone at high altitude (4600m) and in subzero temperatures were also challenging. Finally a sound methodology to operate the drone and collect thermal data to create a 3D model also had to be addressed.
The students already had access to a DJI Phantom 4 drone so we chose to modify that given there was insufficient time to build a custom drone on this occasion. We had our concerns it would be able to fly at an altitude of 4600m as it was close to the manufacturers recommended limit. Effectively propellers would need to spin faster in thinner air to create lift, depleting the battery faster. To our advantage we had the fact the air was cold making it denser and easier to create lift. A second thermal camera also had to be attached at additional weight. And finally a requirement to fly for enough time to cover a substantial sized grid that was marked out for study below.
Drone Mapping Training
We started off providing some training on different mapping packages such as Drone Deploy and Pix4D. In the meantime we got started designing a payload package for the FLIR VUE 640 Pro R thermal camera that would be light. We had to speculate if the drone could handle the thin air at higher altitudes (not easy to test in UK airspace) and have a backup plan. We worked on a set procedure for operation in the expected environment, up most was always personal safety on the glacier.
A few days before the trip there was a training mishap where one of the test drones fell out of the sky and crashed. We suspect this was from a manufacturers fault allowing the battery to fall out. The drone was destroyed. In some respects we were lucky as the much more expensive FLIR thermal camera wasn’t attached at the time. (At time of writing DJI have not yet offered a replacement to the students).
Not all was lost, calling around local suppliers we found local store Kooltoyz had a spare frame that had been returned and was missing a camera. This gave an opportunity to make the drone lighter without the stock video camera always being attached. Given all the modifications the new drone was ready – nick named Frank (for Frankenstein).
At Longniddry beach we performed some trials at low tide as the surface texture here was a mixture of sand and rocks similar to the surface of a glacier. We also provided advice on use and transit of the equipment and batteries on airlines – not an easy trip and kit has been know to be confiscated.
Rosie and her assistant left for their month in Peru and we got news back the trip was a success. So much so Frank earned a second trip to Iceland. The required data had been collected. Frank had made it back from his trip half way across the globe. This was fantastic news that the study was a success. Secondly for Sky Tech that our customisations and training worked perfectly for the students to complete their task. Analysis of the data continues at Edinburgh University Geospatial Department. What a fantastic opportunity for us to work with others on a custom drone project. It was rewarding to see others gain confidence with this drone technology.