Drones for Surveying

Create 3D Point Clouds to Manage Land Development

3D Point Clouds Help Manage an Innovative Development Project  

Paving the way for one of Palm Beach County, Florida’s most innovative development projects in a generation requires meticulous planning.

Located on more than 4,700 acres in prestigious Palm Beach Gardens, the Avenir development is a mixed-use, sustainable community that will include 3,900 new homes, 300 acres of lakes and waterways, a golf course and even a working farm.

So, when Caulfield & Wheeler, Inc., was selected as the surveyor of record for the high-profile project, the civil engineering, surveying and landscape architecture firm turned to our sister company, GeoCue, for their industry-leading LiDAR technology and software to produce the deliverables.

GeoCue and Microdrones have joined together to provide civil engineering and surveying professionals with top-notch products, tools, and support needed to produce high accuracy LiDAR and drone mapping. For the five-year Avenir project, Caulfield & Wheeler is relying on GeoCue’s TrueView 3D Imaging Sensor and processing, analyzing, and visualizing point cloud data in LP360.

The Avenir Land Development project site.

“One of the benefits of using the GeoCue TrueView 635 sensor is the increased accuracy allowing us to survey very large swaths of area with very low accuracy deviation,” said Andrew Beckwith, Caulfield & Wheeler’s director of special projects and UAS operations.

The Avenir project will keep Beckwith and his colleagues busy, providing topographic surveys, contours and layout planning as work progresses. GeoCue tools came in handy during one such survey that took two days and covered 700 acres, including territory that ranged from active construction sites to a wetland to areas with dense vegetation.

Getting up in the air

With calm winds and partly sunny skies, weather conditions were ideal to fly when Beckwith and colleague Jason Cloninger arrived for the first day of this particular project ‑  a topographic survey for a boulevard that will run through the heart of the gleaming new development. Deliverables also included an aerial orthomosaic photograph.

A UAS pilot and LiDAR technician, Cloninger will pilot the unmanned aerial vehicle and Beckwith will serve as a visual observer. “A big issue we have at a site like this is multiple construction vehicles driving around,” Cloninger said. “We always need to be looking for traffic around us or our flight zones.”

Andrew Beckwith and Jason Cloninger, from Caulfield and Wheeler, monitor their drone LiDAR flight.

Other potential issues to stay on guard for include small, low-flying planes from a nearby airplane pilot school and a limited line of sight in some areas because of tree lines. With about two miles to survey for the first day, Beckwith and Cloninger will have to move a couple times in order to maintain a line of sight and radio frequency.

After checking to make sure the area was clear to fly, it was time to upload the mission and get in the air. The GeoCue TrueView 3D Imaging Sensor payload on the drone includes sensors, dual cameras and IMUs that are compatible with all drone platforms that can support the weight.

Day 1 went without a hitch. To finish up, Beckwith and Cloninger returned to the office to get the data ready for processing and prepare for the rest of the mission.

Saving time in the field

The focus of the second day was the last stretch of the two-mile survey area, which included some new potential challenges: a railroad and busy highway, as well as wetland and a more heavily wooded area bordered by a canal. It will be important to review the mission plan to make sure they don’t go over public roads, and Beckwith’s job as visual observer will especially be important for safety.

The plan calls for flying the drone again at 250 feet, which will provide enough height over the tree line but still below the altitude ceiling for the nearby aircraft.

“Drone surveying gives us the opportunity to hit areas that field crews might not be able to get to,” Cloninger said. “It also cuts down the time of being able to process the data and collect the files that we need for the project managers.”

Jason Cloninger reviews 3D Point Cloud LiDAR Data in LP360

It’s a process made easier by the GeoCue TrueView 635 3D sensor, Beckwith said. Using LiDAR can be especially critical to survey areas with dense vegetation.

“These areas are inaccessible to traditional GPS field crews,” Beckwith added. “Using aerial LiDAR allows us to collect infinitely more data than a traditional GPS field crew can collect in a fraction of the time.”

The second day went as planned, too, and hardware worked without interruption. The only issues they had to navigate were out of their control, like low flying planes and construction vehicles.

With field work complete, it was time to return to the office, recharge the batteries and get ready to process the data in LP360.

Producing the deliverables

There’s an important step to take before digging into the deliverables — making sure files are correct and the measurements accurate when uploading into LP360.

“We’ll be able to generate a ground surface, .las point cloud that contains millions of points across some 700 acres,” Beckwith said. “It will be almost infinitely more than you would ever be able to gather with a traditional surveying crew.”

Once the check is complete, the first step is to run the data through PPK (post processed kinematic) processing to adjust for accuracy using corrections from the base station.

The next steps in the classification and quality control process:

  • Analyze and create the flight lines
  • Turn the flight lines into TrueView trajectories
  • Geocode LiDAR to produce the point cloud

It was then time for Beckwith to move on to the deliverable phase. First, he used the LP360 to extract a contour surface from the LiDAR point cloud.

“LP360 makes this extremely easy,” he said. “You can do a couple hundred acres in a minute or two.”

LP360 software was used to process the data from the Avenir Land Development Project

Once complete, Beckwith exports the data into civil engineering computer-aided (CAD) 3D design software that, among other uses, can help verify classification. For example, the CAD program at one point showed a pyramiding of contour lines that seemed to indicate about a 40-foot change in elevation on a property that was relatively flat.

Beckwith knows this is vegetation that needs to be unclassified. He goes back to LP360, zooms into the area that showed the pyramiding and, with a few clicks of the mouse, corrects the file. He reviews the rest of the file for any other inconsistencies.

Satisfied with the quality of the surface, Beckwith imports the orthomosaic file to place under the surface. He runs another check to make sure the contour lines match up with what he’s seeing in the orthomosaic.

Once the file is saved in CAD, Beckwith is ready to send the finished product to the project manager.

“We were able to generate an extremely high-definition orthomosaic photo, which allows you to zoom in and almost read someone’s license plate from 250 feet in the air,” Beckwith said.

He also produced the ground surface, .las point cloud that included more than 70 million points.

“To do a heavily vegetated area with marsh wetlands would take weeks with a traditional field crews,” Beckwith said.

“Our UAS operations department was able to use the TrueView 635 in conjunction with LP360 to complete the survey in three days, including planning, operations, processing and deliverables.”

For more information on how to put drone LiDAR to work for your projects, schedule a meeting with one of our helpful sales representatives.