Drones are increasing safety and lowering costs on construction sites, as well as infrastructure and engineering projects, mining, and agriculture. One of the fastest growing use cases for UAVs across all of these industries is volumetric stockpile and aggregate inspection.
Until very recently, volumetric analysis required workers to collect data by physically climbing on stockpiles with heavy and expensive equipment on their backs. Depending on the type of stockpile, gathering data in this way can be very risky. So inspectors have had to make the choice between good data and their own safety.
Not only are drones safer, cheaper, and capable of producing more accurate data, but they also can provide different and new information when equipped with certain sensors. If you’re interested in incorporating UAVs into your operations, but are uncertain how they might fit into your existing workflow, here are six best practices to get you started.
Set Up Ground Control Points
Setting up ground control points (GCPs) with either high-visibility paint or QR code targets is important to ensure the accuracy of the data collected. This is especially vital when you are flying over a site several times and need to compare change over time, or when the stockpile is large. In a recent Skycatch-DJI webinar, presenters recommended a minimum of two GCPs and five checkpoints.
Secure the Job Site
Typically, overflying people isn’t a concern when collecting stockpile data, but it is still vital that you follow your general operating manual to the letter. This means wearing the proper safety gear, checking for any potential hazards, and coordinating with all personnel. A costly accident negates the savings and safety improvements of using drones, and failure to conform to proper procedures may save a second of your time, but it could end up setting back your drone operation by months or years.
A general operating manual and standard operating procedures are essential for increasing productivity and lowering costs. If you don’t yet have one, consult this article by Skyward’s chief pilot, Tariq Rashid.
Plan the Flight, Gather the Data
With Skyward, you can plan and draw flight plans directly on our interactive airspace map. This makes it easy to show your field crew exactly what they need to do and ensure that you’re complying with airspace regulations. If you’re automating the flight, you can use an app like Skycatch or DroneDeploy to create a flyover pattern to accurately capture the entire stockpile. These apps can also quickly process the data collected into 2D maps or 3D models.
Verify Data Onsite
As advanced as the technology is, it’s always possible that the data collected may be incomplete or somehow corrupted. If you discover this after the fact, you’ll have to dispatch a crew again, wasting time and increasing costs. This is why it’s a best practice to always check your data before you leave the job site.
In particular, pay attention to the edges and make sure you have all the information you came there to get.
If everything checks out, then you can perform a simple check of the accuracy of the data by comparing the point cloud to the GCPs. Once this is done, you can then calculate the volume of the stockpile and produce a variety of outputs: 3D models, orthomosaic maps, and more.
Now that you’ve collected the data, what’s the best way to organize it? No matter which software you choose, make sure that you’ll be able to compare the measurements you collect over time against each other. Ideally you’d be able to collate this data alongside the relevant financial, accounting, and logistical information which will help better manage each element of a given project. Combined with 2D and 3D maps and models, you should have an accurate and complete picture of your aggregates.
It bears repeating that maintaining UAS equipment is vital to the continued success of any drone operation, ensuring the safety of everyone involved, and safeguarding the investment made into this technology. It is always more efficient to perform repairs when a UAV is not in the field, and a serious equipment failure can create costly problems, or skew the accuracy of the data collected. Skyward provides tools to track flight hours and schedule maintenance, so that you are less likely to be surprised by an error or malfunction.
Other Use Cases
Similar procedures can be deployed for several other use cases in engineering and infrastructure: inspecting hundreds or thousands of miles of high-voltage transmission lines, making sure highway construction is up to standards, checking the face of a dam for any signs of stress, measuring cut and fill, or generating 3D renderings of highwalls at a mining site. The possibilities for this technology only continue to grow, and early adopters are already seeing the dividends of being ahead of the curve.