My first experience with a remote-controlled flying aircraft was a toy helicopter I had purchased for my son. His interest in it didn’t last long. It was when he got tired of playing with it that I got my chance to fly it. It was tricky to control but fun to fly around in the house for 5 minutes, after which it had to be plugged in and recharged for an hour. The thrill of flying this RC copter was short-lived. Several years later, the consumer drone industry was booming, and I received a Tello drone for a Father’s Day gift. The Tello drone is one of the first that used sensors to hold it steady while hovering. This small quadcopter had a 5MP camera that could capture 720p video. It was then I began to see real-life uses for this flying camera.
One of my first flights with the Tello was to inspect my roof, which needed repairing. I captured pictures and videos of the roof to submit for an estimate, which was an accurate estimate sight unseen. I gained perspectives from vantage points only obtainable from a drone. Unfortunately, the Tello battery lasted about 10 minutes, so the fun only lasted 30 minutes with a few charged batteries. But it was the ability to fly this toy camera to locations not otherwise reachable, that stuck with me. Plus, it brought back memories of how we used to plan missions in photogrammetry class while in school for my surveying degree. So much has changed.
A few years later, I decided to put my surveying and civil engineering knowledge to work in a way that could help construction companies and farmers improve their bottom line. So, I purchased a highly accurate Real Time Kinematic (RTK) quadcopter along with an RTK base station to start UAmetry, LLC. The reason for my choice was due to the highly accurate GPS positioning system it offers. I felt this kind of accuracy is essential to conduct business and bring value to clients. Being able to place the drone within a few centimeters of a previous location took the guesswork out of doing time-lapse photography and videography, enabling me to produce quality presentations that become magical for clients to watch. The age of flying toys has advanced into the age of flying tools for photogrammetry or videography.
The most significant savings will be to use unmanned aircraft. Renting a pilot and a manned aircraft to take photos could be anywhere from $10,000 to $50,000 for each flight, making regular progression reports hard to justify. While on the other hand, employing drones for the job makes it more affordable at a fraction of the cost. Routine daily or weekly flights become easy to incorporate into the project plan at this level of affordability.
Progression photos or videos are becoming increasingly more critical for companies to not only keep stakeholders in the loop but also document site changes. One common photo generated is an orthophoto. An orthophoto is a puzzle like mosaic of all the mission photos stitched together into one geometrically corrected picture, to:
- help visualize current project conditions
- superimpose design work
- perform linear measurements
The pictures that make up the orthophoto are geotagged with GPS location, altitude, camera information, and more. This embedded data is then used to stitch together all of the overlapping images; resulting in a geometrically corrected orthophoto that can be used to do measurements on.
Photogrammetry software processes overlapping photographs to generate a point cloud.
More incredible is how the photogrammetry software will generate a 3D model from the 2D photos. Linear and volumetric measurements can also be performed using an interactive model interface.
Stockpile volume calculations are as easy as outlining the pile. Cut and fill computations become simple map comparisons. Contour lines can also be overlaid and labeled on the model to show terrain elevations.
A Digital Elevation Model or DEM is a particular type of 3D model that shows the surface or terrain.
Interestingly, this type of model is a 2-dimensional raster image that uses colors to represent changes in elevation. Each pixel holds elevation information and is colored appropriately to produce gradations between the different values. A DEM is used to analyze and visualize the nature of the terrain it represents. They are useful for landscape modeling, city modeling and visualization, and often required for flood or drainage modeling. The DEM above represents lower areas in dark blue and higher elevations in green making it very easy to visualize the relief.
Drones today are packed with technology to improve flight control, location accuracy, and photo quality. Companies are taking advantage of these enhancements to benefit their bottom line. Photogrammetry software outputs provide clients with photos and models to visualize current site conditions, document project progress, or perform measurements and analysis. Contact UAmetry, LLC, to discuss how we can help take your company to the next level.