My name is Seth Pinnoo. I am a graduate student in Department of Geosciences at The University of Tulsa. This past summer, I had the opportunity to complete an internship with Imerys, an international mining company focused on industrial minerals. I worked as a drone survey intern based out of the mine planning office located in Fernley, Nevada. Here, they mine diatomite, or diatomaceous earth, which is a mineral derived from the remains of microscopic, fossilized sea or freshwater algae. This naturally occurring mineral has a wide range of applications including filtration, agriculture, cosmetics, paints and pharmaceuticals. All the mine quarries I worked with were open pit/surface mines.
As a drone survey intern, I was tasked with creating updated 3D models of the quarries. Before I could begin, and before I even arrived in Fernley, I had to pass the Unmanned Aerial Systems (UAS) certification exam to obtain my license to fly the drone for commercial purposes. Once I arrived in Fernley, the next step was to learn how to operate the drone and GPS system. The GPS is necessary because when the drone is flown, there are control points located in the survey area, and the location of these control points needs to be measured to define a location for the survey area and to properly align the photos the drone takes. When the drone is being flown, it takes a picture every few seconds, and with the pictures aligned via the control points, an orthomosaic is created.
Now knowing how to use the equipment, I was ready to design and conduct my own surveys. The quarries in Fernley had already been recently flown, so my supervisor decided I should fly surveys of the quarries in one of the company’s other mines located in Lompoc, California. I had to determine how many surveys to do, the size of each survey area, how many control points would be needed for each survey area and where to place them. This was a challenging task because control points must be spaced out across the survey area and out in the open, so I had to be sure to avoid vegetation and roads. I also had to make sure each location was accessible and not on a quarry wall. I had to have as much planning done ahead of time, as I would only be there for a few weeks, and I would be out by myself.
Setting up and conducting the surveys went well, free of any major obstacles. Minor adjustments were made to some of the survey plans, including changing the size of the survey areas and adjusting the number and location of some of the control points. In the end, I placed 75 permanent control points and conducted 10 drone flights covering 1,221 acres. Also, while I was in Lompoc, my supervisor gave me a side project to collect some samples from different units, which I would later determine the density of by using a 3D scanner. I did this to estimate the tonnage of the different formations, so the company would know how long it would take to mine as the haul trucks can only carry so much weight at a time.
With all the photos and data collected, it was now time to process and analyze them. First was to align the pictures to create the orthomosaics, all of which came out with a mean RMS error of 0.3 feet or less. The next steps were to create a point cloud, contours and, lastly, a digital terrain model (DTM), which was then compared with a 2019 LiDAR survey to see the changes in the quarries. Most of this processing was done in Surpac, which is a common geology and mine planning software. Within Surpac, I was able to create and compare cross sections of my surveys to the 2019 survey. My supervisor then used the differences to calculate how much material was mined and compared that with the records they have of how much was moved via the haul trucks.
Near the end of the summer, I got to fly to the U.S. headquarters in Atlanta, Georgia, to present my work to the company and other interns. This trip, and the internship as whole, was a very valuable experience for me. I got the opportunity to learn the ins and outs of the mining industry, and in general how a position would be in the real world as this was my first industry experience. I learned how to use new equipment and software and how to design, manage and execute a project from start to finish. I also got to meet and work with lots of great people, from geologists to managers to engineers. I was able to learn a lot from this internship experience that will help me once I graduate, no matter what position or industry I may end up working in.