by Andrew P. Sargeant, ASLA, Mike Fox, ASLA, Aubrey Pontious, Associate ASLA, and Russell Thomman, ASLA
Drones 101-1000 was the first Digital Technology Professional Practice Network (PPN) webinar of 2021. The PPN identified drone use in landscape architecture as a topic for which many of our members would like information and resources. The ending of the title, “101-1000,” implies covering everything from the basics to advanced topics with regard to drone use in the field of landscape architecture. The PPN may have more “101-1000” webinars on other topics in the future (our second webinar of the year, a BIM Roundtable with EDSA and SmithGroup, took place earlier this week and will be available as a recording soon), as well as a follow-up to this drone webinar.
Mike Fox, ASLA, and Aubrey Pontious, Associate ASLA, of WPL opened the conversation. Mike started by discussing why he was initially hesitant about incorporating drones within WPL’s practice. He was worried about cost, frequency of use, and other practical concerns. He talked about the unique opportunity to employ Aubrey as both a landscape designer and a potential drone pilot and detailed the negotiations that led to Aubrey becoming a stable resource within the company for drone use, including licensing and equipment.
Aubrey, prior to joining WPL, had some previous hobbyist experience with drones which allowed him to make the case for the firm to help subsidize his exploration and training for drone use in the office. Aubrey outlined some of the use cases within WPL’s practice, including marketing imagery, site surveying, and construction administration. Many of these use cases could be incorporated into any size or type of practice for relatively low cost.
Russell Thomman, ASLA, director of Digital Innovation at RVi Planning + Landscape Architecture, continued the conversation and covered more advanced drone use and techniques. Russell explained how his use of drones within the office has now developed into a wide variety of services. He made it clear that these services were not immediately economically viable or readily wanted from clients but after continued exploration they have now seeded themselves within the practice.
Russell detailed some of third-party software along with the actual hardware necessary for 3D site visits, construction administration, and 3D rendering. In combination with his Mavic 2, Russell uses a handheld 360 camera to offer a comprehensive inventory of site conditions. Russell also talked about using GIS in combination with data aggregated from the drone to “tell stories,” via ESRI web mapping tools. Russell’s ability to go beyond the conventional representation of the landscapes is a product of continued exploration and a combination of new and existing technologies.
Our Drones 101-1000 webinar—check out the full recording below—is part of the PPN’s goal to support and encourage landscape architect’s efforts in research and development of design technology in the field.
Aubrey, Russell, and Mike also took time to answer questions after the webinar and some of their responses are listed below:
How much of Aubrey’s time is used for drones?
Mike – Aubrey’s time is somewhat variable as we have him go out to shoot sites when there are gaps in the schedule. Occasionally he can hit a few sites in an emergency if we need to see a construction issue or get something for an upcoming interview. Generally, if you add it all up it may only be a handful of hours in a week.
Would you mind talking about data size and storage?
Aubrey – I have two microSD cards for my drone—8G and 32G. Since I unload files after each mission, they have been of sufficient size. (Make sure any microSD cards or other storage are compatible with your model of drone.)
Russell – When performing drone mapping, the amount of data gets chewed up quickly. For a 100-200 acre site, you are looking at around 500-1,000 images at 10-12MB per image. The orthomosaic is 1GB+, and the point cloud can be even larger. Additionally, consideration for video size needs to be considered. If filming a site for internal purposes, 4K video is heavy to work with and can add additional time to processing video. I recommend shooting non-marketing content in HD (1920×1080) to save yourself time and storage space.
What gives you the point cloud?
Mike – The camera or sensors on the drone will shoot each point and gather its x, y, and z coordinates along with a color value. It will do this for thousands or tens of thousands of times (or more) depending on what resolution you are intending to collect.
Russell – The process for getting the point cloud with drone imagery is called photogrammetry. This is essentially getting measurements from photographs. Like Mike states above, this is done by triangulating common x, y, and z points from overlapping photographs.
What is the drone interface’s software name?
Aubrey – I use a DJI Phantom 3 Standard and use the DJI Go App (primary control) in conjunction with Drone Deploy or Pix4D (secondary control for running pre-programmed flight routes not available in the DJI Go App). Both are open simultaneously.
Is there a way to coordinate the z-axis with the civil survey so that you are getting true elevation data instead of relative elevations?
Mike – Yes, you would set this in your CAD software upon importing the points. Some software is more intuitive at this than others.
Russell – You can register the photogrammetry point cloud to Ground Control Points (GCPs), or visual targets, that are laid out prior to the flight.
Can you talk a bit about insurance and liability? The firm I am at recognizes the potential of drones but the major roadblock for conversation has been liability and that our insurance does not cover drones.
Mike – Our insurance covers survey work and instrumentation, so it was not a big leap to add another piece of equipment. From a liability standpoint, we have had the insurance company add some language to support drones. There is just as much potential liability with a drone as there is with a company truck, for example. It all depends on the coverage types your insurance carrier is willing to provide. You may have to get supplemental insurance or review your total insurance plan when it comes time to renew premiums.
Could you suggest some drone types/models/brands to research?
Mike – There are so many to choose from. We have used DJI, but there are a lot of good brands: Ryze, Ruko, Snaptain, Holy Stone, Potensic, to name some of the popular brands. You can find a number of sources to view top-rated drones. Try checking Popular Mechanics, LifeWire, CNET, or other reputable tech blogs.
Russell – DJI is the obvious choice for quad copters. SenseFly is another brand with an excellent reputation that makes fixed wing mapping drones as well as a quadcopter. They also make specialized cameras that can assess plant health, heat loss, etc. Skydio is another brand that is made in the US that is gaining traction in the space. For third party vendors, you need to look and make sure that the drone you are buying is supported for the software platform.
If you are documenting a construction site can you fly a regular pattern and get images at the same coordinates?
Mike – If I understand this question correctly, yes, you can, within reason, get images at the same coordinates as last flight so you can document comparable progress of a site. I don’t think it is perfect, but it can be done.
Russell – Surveyed Ground Control Points will ensure that your results are consistent over time. Without the GCPs, you open up room for major errors in data reliability.
Do I have to be licensed?
Yes, the speakers recommend you get licensed in order to fly to ensure that you are covered for liability.
Aubrey – FAA requires you to be licensed for monetary gain.
Russell – Even if you are working “pro-bono,” if your client is a commercial entity you need to have a FAA Part 107 License to provide the service.
Do you have any specific drone certification programs that you could recommend?
Aubrey – I took an online course through a major university. Check your local institutions for in-person availability. I would recommend an in-person drone flight class or an online flight simulator to increase your competence in operation of any drone.
Russell – I have used 3D Robotics (3DR) study material for both times that I have renewed my certification.
Has any work been done to create virtual reality site visits?
Mike – We have not done this—yet. I don’t see why we couldn’t.
Russell – Yes, you can use the spherical photo capture setting on the drone to capture 360 degree imagery. You can also view a point cloud mesh in a platform like Sketchfab and view in a VR headset.
Do you fly in the rain?
No, it is not recommended to fly in inclement weather.
What are the difficulties of getting a flight approved within restricted air space? Or near federal vs. small local airports?
Mike – We have to file with Navy and other DOD guys. It takes pre-planning, but is not as complicated as…well, it isn’t as complicated as permitting wetlands.
We have a Mavic Air 2. Do you have any experience with that model? It is not supported by some of the third party map developers.
See DroneDeploy for more on recommended and supported drones.
How do you convert the drone information to a contour map?
Russell – The process is called photogrammetry. I recommend looking at sites like DroneDeploy and Pix4D.
Can you recommend a starter drone that has controls like those you all use?
Russell – I would look for a used DJI model. They offer the most advanced flight control and are less likely to fly away or crash. Look for a DJI Phantom 3 Advanced, or a Mavic 1.
Have you used drone technology to evaluate the ‘success’ of a project? (e.g. habitat establishment, informal paths, flooding, etc.)
Mike – We have flown sites to evaluate shoreline conditions for stabilization and restoration projects. We will be flying it post construction, too.
Russell – Yes, and this is one of the advantages of having the service in-house. Typically you have to absorb the cost internally, but there is a revenue capture strategy opportunity for ongoing quality assurance.
How long does it take to go from complete novice to flying?
Mike – In 30-90 days you can be flying well.
Russell – I would recommend somewhere in the neighborhood of 40 hours. Keep in mind that your flight times will be around 20 minutes. Start small in an open area free of obstructions. Grow your confidence as your flight skills progress. DJI also offers a flight simulator app that works with their controller. This is a great way to practice learning the functions of the drone without putting yourself or property at risk.
How long does it take to get approval to fly a site?
Aubrey – Using an app like AirMap or similar, if at or under the height limit posted, approval could be within minutes if submitted to an automated request.
Russell – The LAANC system has sped up the process a lot, but worst-case, plan on 30-90 days if it is controlled airspace.