Technology

Turning Drone Photos into 3D Surveys Using Photogrammetry

How does 3D mapping software transform 2D drone images into 3D site models for analysis? The key to successful, accurate 3D drone surveys relies on aerial drone imagery, ground control data, and the science of photogrammetry. 

So, what is photogrammetry and how does it work? Photogrammetry concepts can be confusing even for professionals who’ve already flown drones on their site. That’s where the Propeller Aero drone data processing platform truly shines, aggregating images and data to create highly accurate 3D maps and models for use in a range of industries, including construction; waste management; mining; and aggregates.

Image source Depositphotos

Drone photogrammetry explained

As drones survey a site, they record thousands of images to document the area from every angle possible. Why so many photos? Successful drone surveys require an 80% overlap on each picture to make the orthophoto—the 2D aerial image of the site—and a digital terrain model—a topographic model of conditions on the ground. Combined, the orthophoto and the digital terrain model create an accurate 3D model of your site.

Photogrammetry refers to the process of measuring real-world objects and terrain features from aerial images, in this case those collected by a drone. By referencing the multiple vantage points of locations and features on the ground, Propeller’s photogrammetry software creates 3D models with geospatial information collected from the drone and the ground control points. The end result is a highly detailed, highly accurate survey—within 1/10 of a foot when done correctly.

Drone photogrammetry software: A look behind the curtain

Drone photogrammetry software stitches together the thousands of images captured during flight—it’s a difficult process made easy with the help of technology. The software recognizes the often-complex patterns of physical terrain, creating a comprehensive orthophoto easier and faster than it could ever be done manually. 

There are some limitations to the process, though. Surfaces with few features or that are turbulent don’t work well with photo stitching since not enough identifiable features exist to distinguish the images. Photogrammetry is also less effective on sites with extensive vegetation—for those sites, another technique called lidar is preferable. 

Drone photogrammetry is generally a better investment than lidar for earthwork management operations, including civil construction, waste management, mining, and aggregates.

Photogrammetry generates better data, faster

A photogrammetric survey results in a point cloud and orthomosaic, which is then layered over the elevation model to create the final 3D model of a worksite, complete with accurate geospatial information. 

How can you use that information? It all depends on your industry-specific operations. You can use them to calculate earthwork quantities or verify work on a construction site, or monitor landfill capacity and check specific cell density. Need a quick update regarding the volume of stockpiles or areas to be excavated at a mine? Models created with the help of photogrammetry can help you with that, too. 

No matter how you plan to use drone data, photogrammetry is the ideal processing solution. You can obtain the information you need with exceptional speed and accuracy, helping you optimize jobsite workflows throughout the course of a project.