Using Drones in Construction: The Beginner’s Guide
So you want to use a drone on your construction site?
Advances in technology have made the drone an affordable tool for worksites. While they may seem like fancy pieces of equipment, the use of drones in construction has become no more unusual than a GPS rover, but just as vital, in recent years.
Unlike traditional surveying equipment, however, you don’t need tons of special training and education to use it.
Used correctly, drones enable faster, more economical, and higher-resolution surveying without sacrificing on accuracy. A successful construction site drone program can provide your business with accurate, up-to-date information on your site’s progress and productivity, and information you can use to ensure high-quality work and minimize operational risks and costs.
Collecting and processing your data is only half the story.
Web-based platforms can translate your raw data into something readable and actionable. Take our own Propeller Platform: it takes your data and transforms it into a 3D survey of your site. Fully navigable. Fully measurable. It’s run in your browser, so you can forget about the clunky and complex desktop software of the past.
Don’t have time to read the full guide right now? Download the full guide to drones in construction, plus gain access to additional content.
Key components of a successful construction drone program
You’ll need the right hardware, the right software, and the right licenses (if applicable). We’ll go through these one by one further down.
It’s not unusual for organizations to invest a lot of money into research and experimental drone programs. The tendency is to put a ton of emphasis on hardware. This often overcomplicates things, and leads to building custom drones or signing up for long-term drone leases.
But after the test phase has finished, some companies’ lack of scalability becomes apparent. They can’t effectively train their people to reproduce the test-phase success on other sites.
For a successful drone program, remember to keep it simple, scalable, and economically efficient. Basically, choose your program with overall ROI at top of mind.
To learn more about local aviation regulations and restrictions download the complete beginner’s guide to using drones in construction here
Choose the optimal hardware for your worksite
When it comes to using drones in construction there are many to choose from, but to pick the one that’s right for your needs you should consider a few factors. How big is your survey area? What’s your budget? What’s the best camera for your surveying purposes?
Drone type
If your area is less than 200 hectares (500 acres), it can be done comfortably with a multicopter. If it’s larger, you may want to consider either more than one multicopter or a fixed-wing UAV.
(But remember, if you are operating in a restricted area or a busy place near moving equipment, you may not be able to use fixed-wing aircraft due to their weight and the need for a vacant “runway” strip of land.)
Budget
Cost, of course, plays a big factor in your drone choice. Typically, multicopters (especially those made by DJI) are mass produced and can be purchased easily and cheaply.
Fixed-wing UAVs are still made in limited quantities, meaning units are significantly more expensive—sometimes up to a hundred times more pricey.
Availability and ease of maintenance
Along with sticker price, keep in mind the added cost of maintenance and the availability of parts and replacements.
It’s best to stick with simple options that are available at local stores. As with any other worksite tool, it’s best to avoid providers who cannot guarantee quick repairs or replacements. You don’t want to postpone your surveys because you’re waiting on a replacement drone or part.
A great example of the value of availability in action comes from what would usually be a dreaded event: crashing your drone. Recently, one of our partners was flying a site and crashed his drone, due to a combination of high winds and probably mechanical failure. But because he was flying a DJI drone, a widely stocked craft, he was able to purchase a replacement at a local store and start flying again two hours later.
A RTK/PPK-enabled craft
With the release of an affordable RTK craft in DJI’s Phantom 4 RTK, getting uniform survey-grade accuracy across your site is not only possible, but the new standard.
Real-time kinematic (RTK) processing on a drone records GPS information and geotags images as they’re captured. An active base station on the ground sends raw GPS data to the drone, which it combines with its own data to accurately determine position.
During flight, the RTK drone must stay connected to the base station while gathering data. Signal loss can occasionally occur. If this happens, data can be lost while trying to get a signal lock again.
You’ve probably heard of another kind of drone surveying—PPK. The difference between PPK and RTK is where things get tricky because we’re not strictly comparing apples to apples. PPK isn’t hardware; it’s a different processing workflow using an RTK drone.
PPK stands for “post-processing kinematic.” With PPK, the drone will geotag X,Y,Z coordinates to each image based on its GPS unit.
While this is happening, a base is also recording the positional information on the ground, but with much more accurate triangulation.
After the flight, those two sets of GPS data are matched up using the photo timestamp and the drone’s initial GPS data is corrected, giving precise geotags for the imagery. Those images are then used to build your site survey.
Propeller’s own solution, Propeller PPK, allows you to achieve 1/10ft accuracy site-wide with only one AeroPoint and DJI’s Phantom 4 RTK in a PPK workflow.
Cameras
A good camera for surveying purposes should have a 20MP (or better) sensor. Avoid cameras with interchangeable lenses unless you are certain you’ll need that feature (often used for inspections). They over complicate the surveying process and often worsen the quality of data with images that can be out of focus.
Overall, keep in mind the camera specifications that affect ground sample distance (GSD) and resolution.
The GSD is the real-world size of a pixel in your images. This generally sets a physical limit on the accuracy of your aerial survey. For example, if your GSD is 5cm, the survey produced will only be accurate down to 5cm.
GSD is measured in cm/pixel, usually ranging from less than 1cm up to 5cm for aerial surveys. Note that the altitude of your flight also affects this number. If you want to fiddle with possible GSDs, this handy calculator can compute them for you.
In general, make sure you have a high-resolution camera, with a larger sensor and a 35mm-equivalent focal length. This lets you get more detail about any point and increases your image contrast in order to help generate better 3D renderings and point clouds.
If you want to go deeper on this topic, check out our article on what makes a good camera for drone surveys and inspections.
Pick the right software for your needs
As we’ve seen, there are various options for the hardware side of things, but you can usually rig together some combination to acquire the data you need.
Software, however, is a different matter. It’s not an interchangeable tool. Construction jobs are complex, involving many levels of oversight, design, and management. You need to pick the software that’s right for your workflows.
Want to learn more about why software plays such an essential role in successful drone programs? Interested in finding out which flight planning app we recommend to customers and understanding what you really need to know when it comes to selecting the right processing, measurement, and visualization software. Download the full guide below.
Use your construction drone survey data to spend less and make more
Drones cut down surveying times to hours instead of days or months, and they’re cheaper than traditional survey equipment. Let’s look at workflows to see how you can use your drone data to best effect.
Calculate volumes accurately and quickly
Volumetrics is the most popular use case for drones on any worksite. For many construction companies that operate their own quarries, drone-captured data is the affordable source of timely and accurate information on volumes.
Instead of relying on outsourced survey teams or walking around each site with a GPS rover, you can now fly a drone and capture an entire site, usually in a couple hours or less. Once the data has been uploaded and processed, you can get accurate cut/fill volumes and other survey analytics necessary for planning and tracking job progress.
Capturing data regularly is also useful on site when it comes to earthworks. If you’re moving dirt around, you need to be able to quickly calculate the volume of material to be moved. 3D drone-data surveys let you track earth-moving operations safely and more economically than with traditional walkthroughs.
Compare your site against the design
If you’re actively moving earth, regular drone surveys allow you to compare current ground levels against the plan and identify anything going off-track.
You can do this by overlaying design surfaces or linework on your 3D visualization. With all the information on one screen, it’s simple to understand if volumes and elevations are matching design or not. And since it’s a simple visual of the physical space, your findings are easy to communicate to others.
Track your progress and productivity
It’s an unfortunate fact, but most construction projects run over time and over budget. You want an easy way to visualize your site transformation as the project progresses. While it’s particularly important to make sure you’re on schedule and not running up costs, it’s also necessary to inform remote stakeholders on progress and to monitor contractor work.
When you combine frequent, regular drone surveys with something like the Propeller Platform’s timeline tool, you can compare between multiple datasets and visually track changes in a way that makes sense for everyone.
Inspect your assets remotely, faster
Depending on your company and the job itself, you might have assets to inspect on your site. Drones can quickly capture high-res photos that can be viewed in platforms like Propeller. There they can be annotated, then downloaded as a report and shared with contractors or project stakeholders.
Using drones for remote asset inspections not only saves money, but also reduces safety risks for employees and contractors by keeping them away from hard-to-reach or dangerous locations.
Resolve disputes more easily
No one wants to move dirt they don’t have to. Drone technology allows you to have more control over a project and define how much you should pay your contractors based on the actual amount of work done.
Drone survey data, timeline features, and reports can also be used as a tool to solve any disputes with contractors. Because they provide a paper trail of the physical state of the site at every survey, you can easily show where things went and when.
Export drone data into third-party software
Some construction companies often require drone data to be exported into CAD or BIM software for further work.
Processing engines like the Propeller Platform allow the export of high-resolution point clouds, geoTIFF, and DXF files which can be used in a wide range of software applications.
Simplify reporting
Regular drone surveys help deliver up-to-date information to project stakeholders and contractors by providing visual data that they wouldn’t have seen from the ground. And processing your data with an online platform reduces the time and expenses associated with on-site visits.
For example, Propeller has PDF and CSV reports that are easy-to-create and share with your team or your boss.
Use of drones is revolutionizing the construction industry
Construction is a multifaceted industry. With so many moving parts, accountability, progress tracking, and accurate data are key to success.
But as we’ve seen here, it’s too often that you don’t have the tools you need to accomplish your job on time and on budget, not to mention make day-to-day management easier. Drones can drastically improve these issues by solving problems quicker, with less trouble, and through less costly means.
Using a drone on your site does not require someone with extensive special training, often you can learn how to fly it yourself and obtain the required certification depending on where you are located.
A processing platform like Propeller is cloud- and browser-based, which means that you can access it from your device from wherever you are.
This also means that your team has the same access, making collaboration easier than ever. And because drone surveying is quicker than traditional methods, you can have more up-to-date data than ever before, which enables everyone to make better, data-driven decisions confidently.
Now all of this is great to think about theoretically, but when it comes down to it, what are companies actually seeing when they start using drones and processing software?
Here are a few examples of real people solving real problems on their sites:
“I can go out and fly a site in two to three hours and then just upload everything to Propeller and come in the next day, and it’s done. If I have a question or something, I can just email someone and usually within a few hours—or within 24 hours—I have a solution back. It simplified everything that we do. Before, we weren’t doing a lot of monitoring on every site, so now we try to fly every site at least once a month.”
—Jim Croan, JRC Construction
“Being able to produce and share centimeter-accurate mapping that’s rivaling GPS topo survey is pretty unique and awesome. Propeller’s software facilitates more fluid communication as now we’re all working on the same page with the same reference information.”
—Ray Penner, Scheffer Andrew Ltd.
If you’re interested in reading more about how Propeller can help you measure and manage your site, download our full ebook: Drone Data Analytics for Construction