Summer 2020 | eWavelengths

In January 2019, crews began the survey. Because the SCT is located within CLT's airfield, CES needed to perform their work overnight to avoid disrupting airport operations and for safety.

To meet the accuracies and deadlines required, CES surveyors arrived at the field with multiple Trimble technologies, including R8s GNSS receivers, S7 total stations and a DiNi digital level, all of which had been purchased from Duncan-­Parnell.

They first set control using R8s GNSS receivers, occupying each control point multiple times and calculating the averaged coordinates for each point. They then ran a closed traverse loop using the S7 for horizontal control and the DiNi digital level for vertical control to within 0.01 ft. With control established, three different survey crews used multiple Trimble S7 total stations to collect all the field data including ground shots, utilities and critical tie-in points.

Hudson and a colleague scanned the cargo area, arriving on site one night at 11 :00 p.m. They used the previously established primary control network and set additional "spur" control points as needed. Setting the SXl O on a chosen control point, Hudson captured the scene, collecting not only the concrete joints and surface elevation variations, but also the tops and bottoms of retaining walls, storm grates and building corners at distances up to 300 feet from the instrument. In 1 0 scanning set ups, his crew captured the entire 40 acres in a single seven-hour shift.

"I went to the site expecting it would be a three-night job, and I was shocked that we got it all in one night," said Hudson. "Our dealer, Duncan-Parnell, had assured me that darkness wouldn't be a problem, and they were right. I not only acquired millions of 3D points that clearly show all the concrete seams and subtle grade variations, I captured substantially more data in just 13 percent of the originally-planned time." Back in the office, Hudson processed the point cloud using Trimble Business Center software and removed any extraneous features such as parked airplanes. He then created a 3D topographic model of the 40-acre concrete apron and exported it into AutoCAD to produce a final 3D surface. Two days after capturing the data, CES delivered the topographic survey to their client.

Being an integral part of such a high ­profile project is testament to how far CES has grown from the residential lot surveys it was providing only eight years ago. Duncan-Parnell is honored to have played a supporting role in CES's success, and as a trusted partner, it is committed to continuing to help CES secure the right technology at the right time.