Before a recent concrete pour, Colby Lindsay walked the jobsite to check the anchor bolts. He discovered every single one sat roughly six inches out of position. Catching the mistake before the concrete was poured and the steel arrived saved a fortune.
"That right there paid for the unit," he says, "and probably could have paid for 10 more."
Lindsay is a virtual construction manager and BIM coordinator at CORE Construction. Recently, his company began placing centimeter-accurate Emlid field GNSS receivers directly into the hands of superintendents and project engineers. The bet: let the field teams closest to the work check it themselves while there is still time to fix mistakes.
A company built around quality control
CORE Construction is a general contractor managing K-12, healthcare, and municipal projects in California, Nevada, Arizona, Idaho, Texas, Indiana, Illinois, and Florida. Because much of their portfolio involves complex renovations on existing campuses, precision is vital.
Danielle Williams, director of the Virtual Construction department, leads the push for field tech. Site visits are how her group finds the things worth solving. "It's just what we're seeing our field teams encountering, what they're having the most quality control issues with. That's what drives us to look for new technologies," Williams says of the field teams.
To manage quality, CORE Construction adapts the Army Corps of Engineers' three-step approach: a pre-work meeting with trade partners, an inspection of the first piece of work, and ongoing follow-up checks. The new GNSS receivers support these initial and follow-up inspections.
The data gap drones couldn't close
While the team has used drones for years to map site topography via ground control points, aerial imagery falls short on fine details. From 100 feet in the air, a drone cannot verify a one-inch anchor bolt or ensure a plumbing stub-up lands precisely inside a wall.
"When you're trying to verify anchor bolts for connections to steel columns, those are like 1-inch bolts," Williams says. "From 100 feet in the air, you can't get that close of imagery on it." The same went for plumbing stub-ups that had to land inside a wall.
That left a familiar gap. The drone could tell the team something looked roughly right, but it couldn't confirm the details. When these discrepancies went unnoticed until steel arrived, schedules suffered, and rework was costly.
Before adopting GNSS, CORE Construction's only options for detailed verification were unreliable hand measurements or paying for a licensed surveyor's unscheduled visit.
The check before the surveyor calls
CORE retains licensed surveyors on every project, but out-of-scope calls add up quickly. Bringing full surveying in-house was impractical due to licensing requirements.
Instead, the company found a middle ground using Emlid Reach receivers running RTK (real-time kinematic) corrections that lock in centimeter accuracy on the spot. Now, a superintendent can verify a layout instantly.
"It's a good secondary option to identify if we have a problem, and then we can call a surveyor in," Williams says. "It's kind of like a step in between."
CORE Construction doesn't build off the GNSS receiver data or treat it as the official survey. It acts as an internal double-check and transforms field communication from "we think there might be a problem" to "we definitely have a problem."
Better questions, faster answers
The verification is half the value. The technology also changes how CORE Construction interacts with subcontractors.
By importing survey data and subcontractor drawings into the Emlid Flow field app, the office, the field, and the subcontractors are all reading from the same georeferenced map. When a superintendent who understands that data walks up to a trade partner, the exchange gets shorter.
"So many times I've asked a more educated question, and I get exactly what I need right away," Lindsay says. "Versus them asking for it for months."
That's the part a general contractor feels across every trade on the job. A sharper question, backed by data everyone can see, ends a back-and-forth that used to stretch across weeks. The trade partners spend less time troubleshooting and more time building.
Putting GNSS in the field crews’ hands
Lindsay handpicks the people he thinks will get the most from a receiver—usually the superintendents already feeling the pain—and walks it out to them himself. Often, he just uses it for them for the first time. That's typically all it takes.
The company is now using several units of the Reach RS3, RS4, and RS4 Pro receivers and treating the current stage as a beta, on purpose, across three regions to gather a range of feedback. In Texas, it's mostly superintendents and assistant superintendents. An Arizona team running off-site street work that would otherwise have called for a total station is using GNSS instead. A team in Reno is putting it to work alongside commissioning.
Data moves smoothly across platforms. CORE Construction transfers DXF files between Emlid and DroneDeploy. It recently pulled its DroneDeploy imagery into Emlid Flow as a map layer, so the same drone capture that shows the big picture sits underneath the centimeter-level checks. And because the projects sync through the Emlid Flow 360 cloud platform, a point a superintendent collects in the field reaches the office without anyone emailing a file around.
Scaling up: From field beta to standard operating procedure
Through the summer of 2026, Williams plans to analyze the beta data to establish a standardized framework for GNSS deployment across the entire company.
It’s part of a bigger trend in construction tech: moving accurate data out of the back office and straight into the field. By putting these tools directly into superintendents' hands, general contractors can catch costly mistakes early without slowing down the schedule.
For CORE Construction, the days of guessing or waiting around for an outside surveyor are over. A superintendent can now spot a potential issue, check it in minutes, and move forward with data-driven confidence. Catching a massive error before the concrete pours isn't a stroke of good luck anymore—it’s just the workflow.
