Virtual Meeting? Bring the Site to You!
Regular drone missions can help bring your site to you. With Corona Virus uncertainty increasing, many companies are starting to apply the CDC Guidelines of “Social Distancing” to regular progress meetings and briefings. If this is you, keep in mind that drone data can help you keep your distance through online delivery and collaboration; reducing the need for face-to-face contact. Aerial drone data has always been delivering valuable insight during every construction phase, from preconstruction bids to wall checks and utility placement to site hand-off. Now, drone flights and data can help you take advantage of the CDC’s COVID-19 “Social Distancing” recommendations. Here are a few ways.
Imagine having a super-high resolution picture of your entire site from this morning for your meeting this afternoon. That’s what an Orthomosaic is. It’s like an up-to-date Google map that’s super high resolution-so high in many cases, that you can zoom into individual fan blades on an air handler’s roof unit, for example. “Orthos”, as they are known, are made by collecting hundreds of aerial drone photos of your site in a pre-planned pattern and altitude then using software to “stitch” them together into one high-resolution image. They offer a detailed look at an entire site without having to leave the office or trailer. Benefits include: Import capability into industry software like BIM, GIS and CAD for more advanced oversight and planning; Pre-pour documentation of what’s inside slabs, the quality of rebar install and post-tensioning cables; Façade/structure inspections with no scaffolding, Landscaping insight on water reach, drainage, final grading and landscape features; and documenting “As Built” condition before handoff.
3-D models can be rendered relatively quickly from Point Clouds generated from images taken with stock lenses and cameras on professional drones. The process is much like that for an Orthomosaic, but utilizes more camera angles and Ground Control (for precision models). These interactive images allow for precise measurement and site views not possible with Orthomosaics. Flight tests carried out recently by Embry-Riddle University using quadcopter drones for 3D point clouds and modeling yielded acceptable results at a fraction of the time and cost of laser scanning.. Flying at 100 ft AGl in a double Grid Pattern yielded 28.6 mm accuracy for the Phantom 4 Pro vs 2.6 mm accuracy for the Faro Laser Scanner.* While the Embry-Riddle tests were specifically aimed at collecting data for law enforcement crime scene recreations, the methodology and results are directly applicable to construction.
One of the most useful measurements for the amount of work involved, Volume Calculations give you a fast and accurate way to measure how much material is in a given pile-keeping inventory and off-haul costs accurate. Earthpile Volumes and Stockpile Counts can be calculated with no ground control or benchmarks simply by using parallax, or the offset between photos of the same image in your Orthomosaic. These volumes are accurate to within 2% of traditional measurement methods.
*Flying at 100 ft AGl in a double Grid Pattern yielded 28.6 mm acuracy for the Phantom 4 Pro vs 2.6 mm accuracy for the Faro Laser Scanner. (Cerreta, J. S., Burgess, S. S., & Coleman, J. (2020). UAS for Public Safety Operations: A Comparison of UAS Point Clouds to Terrestrial LIDAR Point Cloud Data using a FARO Scanner. International Journal of Aviation, Aeronautics, and Aerospace, 7(1). Retrieved from https://commons.erau.edu/ijaaa/vol7/iss1/6)
This feature allows you to visually compare planned features to where they actually are on your site. Overlays are useful in a number of ways including: Helping to reduce rework for utility pathways and documenting in-ground utilities; visually showing position of site plans for utility, runoff and equipment clearances on the actual site as it develops, and comparing real-time site conditions against the plans. This can help you catch conflicts early and correct them before they become big problems later.
Accurate contours require ground control points or drone images tagged to benchmarks. This can be time consuming for your drone operator and usually is an added eexpense to normal drone operations, but it saves time and money in the long run compared to traditional methods. Contour measurements allow for more active and competitive pre-bids and accurate site balancing for final grading.
One of the easiest items to capture and deliver, progress photos allow greater visibility into a quickly-developing construction site at a relatively low cost. Seeing photos from the same angles and altitudes each mission allows you to easily recognize specific progress each time.
Be sure to ask for any new progress, perceived problem areas and especially anything that may have been a challenge.
If a picture is worth a thousand words, then video is invaluable. There’s nothing like a simple edited video to see the ongoing progress of your site-and it’s especially useful for those who can’t make it to the jobsite as often as they’d like. A video is an active way to keep you up to date as building progresses.
Remember-If CDC guidelines on COVID-19 have you curtailing your face-to-face meetings or trips to the jobsite, drones can be the perfect solution for bringing the job site to you with aerial acquisition of data and images from the air. Call or email Mid-Atlantic Drones for more information and a free initial flight over your jobsite.