How Drones Make Topographic Surveys 6X Faster

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Headquartered in Gainesville, Texas, All American Surveying (AAS) is a full-service survey firm run by Jake and JT Thompson. They were recently contracted with all of the survey work for a 90-acre residential development project in Texas, and found a number of opportunities to drive significant value for their client by using drones as a topographic survey tool.

AAS was brought into the project on a few occasions: first, they were initially tasked with performing pad and road grade verifications and delivering a cut-and-fill analysis, which would be used before the earthwork contractor started their work. Then, once the earthwork contractor completed their work and brought the dirt to grade, AAS was brought in again to survey the site to verify the work had been done as planned.

Their goal
"Given that this is a 90-acre site, a traditional survey would take 2 to 3 weeks to do," Jake said. "Our client wanted to survey the site in a much shorter timeframe, and we wanted to offer them a way to do that."

For AAS, the large size of the site– and the fact that it was groomed earth with no vegetation–made using a drone a perfect fit. "Drones are increasingly our go-to tool for topographic surveys like this," Jake said. "We knew that it would help us survey the site faster, so then we focused on finding the right one for our needs: we needed a drone solution that had the level of accuracy to satisfy not only our own criteria, but also the standards of the Registered Professional Land Surveyor (RPLS)."

The solution: 3DR Site Scan
Jake and his team decided to use 3DR Site Scan to perform the survey work. The simple workflow in the field, cloud processing, and accuracy were all important factors in their decision. "At the time, the Sony R10C camera had just been added to the Site Scan drone," Jake said. "We tested it, and found that it was incredibly detailed and accurate. We knew that Site Scan would pass the criteria of our Registered Professional Land Surveyor (RPLS). We did a lot of verification between conventional survey and what Site Scan offered, and we felt that the R10C camera provided survey-grade accuracy that wasn’t available in other UAV solutions. We were confident in it, and we felt that the RPLS was more than confident in signing and sealing these deliverables as well."

In order to improve accuracy even further, AAS set 5 ground control points throughout the whole site and used them to georeference their orthomosaic, which was processed by Autodesk ReCap within Site Scan Manager:

Key results
1. 6X faster time to survey deliverable Speed was a priority on this project, and with a drone, AAS was able to deliver. According to Jake, it would have taken about 18 days to perform a manual survey of the 90-acre site, process the data, and finalize the deliverables. With Site Scan, they were able to cut this process down to just 3 days, making their drone survey workflow 6X more efficient than traditional surveying.

2. Detailed cut-and-fill analysis and comparison For AAS, surveying speed wasn’t the only benefit of using drones on this project: with a drone, they were able to collect millions of points and capture their site in greater detail than ever before. As JT said, "With a conventional survey instrument, we’d typically capture the four points of the pad and one in the middle, and create a cut-and-fill analysis to compare the existing elevation with the target elevation." With Site Scan, he said, "We were able to collect way more points, and provide data on anything in between: dips, humps, stockpiles, and more. With the drone, we found areas with excess dirt in areas we couldn’t have found conventionally."

3. Saving their client over $100K and earning repeat work While AAS was initially contracted to perform survey work, their client ended up using the drone data for project management and billing purposes as well. In fact, the data was able to save their client over $100K when in a dispute with an earthwork subcontractor, which also earned AAS extra business on the project.

Here’s how: as Jake said, "Our client was upset about how some of the earthwork had been performed–they didn’t think it was done properly. The contractor said they had moved a certain amount of dirt, and gotten everything to subgrade, but in reality, they hadn’t gotten it to subgrade, and they hadn’t moved as much dirt as they said they had, despite providing a full invoice."

Without proper documentation, there was no way for their client to prove that this work had not been completed properly. Their client was stuck–until they saw the drone data. AAS flew the site on December 12th, and then a month later on January 12th for verification, and compared the difference in earth moved compared to the contractor invoice. They identified a big discrepancy–over 250,000 cubic yards of dirt that had been moved incorrectly–and used the point cloud data to prove it.

"Our client could then could show this to their subcontractor, get them to finish the work as planned, and get them to pay for half of the survey cost and reduce the invoice. This saved our client about $100,000, probably even more." For survey firms like AAS, this ability to verify performed work quickly and cost-effectively is opening up new opportunities for repeat surveys. "Now, our clients can bring us in and monitor their project as often as they want to," JT said.

Next steps
Drones have enabled AAS to perform topographic surveys faster, cheaper, and safer on a variety of projects. A major benefit for them, though, isn’t just the drone: it’s the software they use back at the office, Site Scan Manager, to analyze the data they collect, share it with stakeholders, and make decisions.

With the new Site Scan Manager, Jake said, "being able to fully manage projects and have access to my data anywhere has been priceless. I can collect data, and then in minutes I can get the raw data for different stakeholders to view, and then within a day I can get the rest of the information in detail."

Going forward, now that they’ve established drones as a survey-grade tool, AAS plans to incorporate them on a number of new projects and win new business. "Site Scan has had a big effect on the work we’re doing," Jake said, "It’s making topographic surveying simpler, easier, and faster than ever before."

Hugh McFall is a writer at 3DR, a drone technology company based in Berkeley, California, covering the ways that drones and robotics are transforming the construction industry. He can be reached at

A 2.644Mb PDF of this article as it appeared in the magazine complete with images is available by clicking HERE