Ever seen a drone taking pictures of local real estate or at a local event? These machines are excellent for showing off what is going on in the community from a unique view. This view lets us see our subject and other things going on around. But, what if you wanted to your drone into an industrial workhorse. This is where combining drones with the science of photogrammetry does the trick.
What is photogrammetry? Photogrammetry is the process of stitching multiple images together to make a measurable 3D model. Uses for this science can be a construction site, quarries, farming, cell towers, and more. When properly combining these 3D models with GPS located points in the map you will then gain the ability to accurately measure distance, area, cut/fill volumes, and elevation. Being able to calculate hundreds of measurements without having to walk around and physically take them saves time, which saves money, and decreases the risk for injury in the work field. Have you ever had a client that requests an update? This then requires you to go out, take pictures and measurements on the work site, then go back and send them over to them. But, what if you didn't get exactly what the client wants to see? Then you have to repeat the process. With continuous mapping, you are to make progression maps showing progress and giving them the ease to take measurements. This not only benefits you and your clients but also helps project managers and workers see what is happening and what can be improved.
Is this easy? No. The science behind photogrammetry can be quite complex. This is why programs like Pix4D, Agisoft, and DroneDeploy can assist you in the processing. However, you will still need to have advanced knowledge in data acquisition strategies like Ground Control Point (GCP) placement, flight plans, and decisions made in post-processing that can all affect the legitimacy and accuracy of your map.
How to choose the perfect drone? In the market today there are many drones large to small and priced all over. When looking between drones one critical factor to look for is a global shutter over a rolling shutter. The best way to describe the difference between the two is like a stamp. A global shutter will stamp onto a piece of paper at once, while a rolling shutter rolls from the top to bottom one row at a time. Global shutters will help improve in time acquiring data and distortion. Next, you will need to figure out what all and where you will be using the drone. If you're looking to do strictly mapping look for a drone like the DJI Phantom 4 Pro RTK which gives you RTK accuracy and a global shutter. If you're planning on flying in windy and cold conditions the DJI Inspire 2 is your machine. This drone offers interchangeable cameras, as well as self-heating batteries letting you fly in adverse conditions. The only downside to an Inspire 2 is the battery costs. While you may spend $150 per batter in a Phantom 4 you will spend twice as much on an Inspire 2 due to its dual battery design.
Listed here are just a few of the many strategies one will have to learn to correctly map with drones. Are you looking to implement mapping into your services? Taking it upon yourself can be a steep learning curve. If you choose to hire, I would be happy to assist you in your projects and with prior OSHA certifications, I know the proper safety precautions to take on a job site.
P: 618.554.0052
E: yagerdroneproductions@gmail.com
Sources:
“How to Complete Your First Drone Mapping Project.” Drone U™, www.thedroneu.com/blog/complete-first-drone-mapping-project/#dronemappingtraining.