The Challenges of Using Drone Technology for Mapping

11.06.2020


The rise of new drone technology has quickly made these devices a common choice for mapping across various industries, including mining, agriculture, energy and real estate.

The use of drones in Geographic Information Systems (GIS) offers some serious advantages for end-users — like remote mapping, faster mapping times and 3D models from aerial maps. However, drone mapping tech isn't flawless. While the aerial maps these drones can provide are valuable, some major challenges make these machines less workable for certain projects. Those issues are compounded without the right precautions and planning.

Knowing the advantages and disadvantages of drones for mapping will help mappers plan how they'll approach a new project and pick the best technology for the job.

What Is a Drone Used for in Mapping and GIS?

Recent developments in sophisticated 3D mapping and GIS drone technology, combined with a growing industrial drone market, has made the use of drone mapping tech accessible to a wide variety of companies beyond major industry players with the capital for cutting-edge mapping solutions.

Mapping with unmanned aerial vehicles (UAVs), or drones, uses photogrammetry to capture map data from 2D images that are taken as the drone flies over a project site. As the drone travels autonomously, following a pre-programmed flight path over the site, it takes multiple overlapping photos with a specialized camera or set of cameras.

With 3D mapping technology, these images are then stitched together, providing accurate measurements of length, area and volume — or even full 3D models of an area. The result is a high-quality aerial map of the location, complete with measurements, that project managers can immediately use for planning and site management.

Previously, the only way to use photogrammetry to take the photos needed for this kind of map was to use a manned aircraft. Now, anyone who can afford to buy or rent the right drone and necessary tech can use drones for aerial mapping.

Drone-generated imagery can be used as a powerful basemap, ensuring all project stakeholders have access to basic visual and spatial information about a given site.

Industries That Employ Drone Technology

The speed of drone deployment and the flexibility of drone technology makes it possible to map almost anywhere and at any time. Specialized cameras — like cameras with multispectral sensors that capture the spectral bands needed for crop health analysis — can provide additional information captured from the air.

Drone mapping is used in numerous industries, including agriculture, construction and oil and gas. In real estate, drones are sometimes to used to create high-fidelity 3D maps of a given property, allowing real estate agents to provide potential clients with a look at the building and land, even if they can't be there in person.

Drones can be especially useful for mappers who need to tackle large or hard-to-reach sites, like high-acreage farms, mines or pipeline projects, which may run through remote territory with poor infrastructure. In cases like these, mappers can save time with drones, as they won't need to move around a site to map the area. Depending on the technology available, they may not even need to be on-site at all.

Drone mapping technology also enables remote building or equipment inspection, which can speed up tasks that would otherwise be slowed down by difficult-to-access machines or buildings.

5 Challenges of Using Drone Technology for Mapping

As useful as the tech is, there are some significant challenges in using drones for mapping. Issues like wind resistance, landing and takeoff or site accessibility can all make drone mapping less practical.

Below, we'll discuss some challenges mappers often struggle with when using drone technology for site mapping. We'll also inform you of how to overcome these obstacles with the right planning and prep:

1. Wind Resistance and Poor Weather Conditions

Strong winds can be a major challenge for any drone.

Wind can blow a drone off course. Near waters and steep inclines, wind also tends to gust more unpredictably, resulting in conditions that are harder to respond to without a drone built for flying in strong winds. Wind also tends to be faster at higher altitudes than at lower ones. On projects where a drone needs to fly at a high altitude to efficiently capture images of the site, elevated wind speeds can become a significant challenge.

Because the drone may need to more frequently course-correct due to high winds, it can also eat through its battery life faster. As a result, it may also be a good idea to plan for shorter runs than usual in windy conditions.

Not correcting for the wind's effect can result in a more challenging mapping process and necessitate additional time spent on the project site. You can avoid hard winds and unfavorable weather conditions with time. Depending on the project timeline, however, it may not be possible to wait out unusually strong winds or bad weather, which then calls for the use of more robust equipment.

Some heavy-duty drones can handle high winds and may have protective gear that shields the devices against rain and dust. This kind of equipment can be especially useful for projects where dust may be a major issue — like construction sites — as it can enter motors, rotors and the cooling fins of air-cooled drones. Dust can quickly cause damage by temporarily knocking the drone out of commission and causing costly repairs. The dust can also limit visibility and reduce the quality of aerial images.

2. Drone and Equipment Transportation

Batteries are heavy, and drones are typically only equipped with a power supply big enough to keep them in flight. Even the most advanced drones, built for industrial use, can only fly for around an hour before needing a recharge. This means you cannot fly a drone to a project site, map the area and fly it home. Instead, you will need to transport the drone to the site yourself and recover it once mapping is complete.

For smaller drones, this may not be an issue. If the project site is in driving range, transporting the drone via a mid-size or compact car is often possible. As drone size and distance to the site increases, however, transportation becomes a more serious challenge.

If a site is too far to practically reach by car, a mapper may need to ship the drone there via freight. Many models of large, oversized drones offer advantages like additional flight stability or longer flight times. However, they may be difficult or impossible to transport in smaller cars and quite expensive to ship.

With some careful planning, however, you can arrange for cost-effective transportation.

3. Unusual Site Size or Layout

Site size and layout can also pose issues. The larger a site, the longer it will take to map. While drones can be effective in mapping large sites, it may become difficult or impractical to map the entire area after a certain point. The number of times the drone needs to pass over the site can make a project increasingly complex.

Area layout can also be problematic. Due to Federal Aviation Administration (FAA) regulations, drones typically cannot fly at altitudes higher than 400 feet above the ground, unless that drone remains within 400 feet of a structure. This limits the amount of land a UAV can cover in a single flight.

Fixed-wing drones use wings like an airplane to provide lift, rather than rotors. These drones are much more efficient than ones with rotors, as they don't use energy to hover during flight, takeoff or landing. As a result, they have a significant range advantage and are suitable for mapping larger project areas. The greater stability these fixed-wing drones can offer also helps them manage flight in windy conditions.

Loss of power mid-flight is also a more manageable problem with fixed-wing drones. If power is lost, the drone's pilot will likely be able to safely glide the drone into landing. A drone that relies on rotors for lift is much more likely to face significant damage in this kind of scenario.

If a mapper considers site size and layout ahead of time, they have a good chance of picking equipment and drones that will help them manage challenges like large or unusual sites.

4. Site Terrain and Accessibility

For projects that require high levels of global accuracy, mappers often use ground control points in the form of marked targets that provide additional information to the mapping program. These control points are often necessary for the program to accurately situate the completed map correctly regarding its surroundings.

Being unable to place these control points can be a major challenge. Some project sites are both challenging to access and traverse. Extreme climb, thick vegetation, marshy or unstable terrain and water can all make it difficult or impossible to stage control points as needed. When getting to the site is challenging, it may become harder to support the drone from the ground.

You can overcome this issue, but it will require some additional tech or strategies that call for extensive planning, and these may be difficult to ad-lib on-site. A drone with real-time kinematics, for example, can draw on Global Positioning System (GPS) information and automatically geotag images while it is in flight. After the fact, these geotags can ensure the post-processing software correctly places the final map in the correct location.

5. Complications in Takeoff and Landing

Drone choice, while it may fix other issues, can create additional problems.

Fixed-wing drones, for example, need significantly more space for landing and takeoff than drones that use rotors for lift. If there is limited space available — or if unfavorable terrain would make it dangerous to take off or land — it may be difficult or impossible to use a fixed-wing drone to map a given site.

No matter what kind of drone you use for a mapping project, site terrain can create takeoff and landing challenges. Uneven or rocky territory, for example, can cause damage to any drone if landings are rough. Dense vegetation and tree cover may also make it difficult or impossible to take off from an area, forcing a drone pilot to locate a clearing that they can use.

Before starting a project on certain sites, it may be necessary to scout the place for the most suitable takeoff and landing locations. Sites with especially rough terrain or unique hazards — such as ones that mostly consist of water or are rural with little clear land — may need specialized drones that can manage extremely precise takeoff and landing.


Why Finding the Right Mapping Equipment Matters

Each mapping project is unique and will have its own distinct challenges. That's why it's important to find the right technology for each job. For project success, knowing the challenges you'll likely face — whether those are wind, site accessibility or equipment transportation — will help you make the most informed decisions possible. With the right information, you can work to find the devices that will help you best manage, avoid or overcome these challenges.

For example, you may work on sites with dangerous or inaccessible areas. Drones that can add geographic metadata to images without using control points can help you collect that data without needing to navigate a potentially hazardous location.

When mapping in an area with significant water hazards, you may want robust equipment that you know can help you collect geographic information, even if dangerous or inaccessible terrain prevents you from navigating portions of the site safely.

Once you've started compiling mapping data, you'll also need the right solution to combine that information in a way that stakeholders can use. You may need software that works both on your desktop and in the field. You'll likely use tech that will help you manage and organize your Global Navigation Satellite System (GNSS) data collection, so it's easy to use after you've finished collecting map data. Or, you can try a platform that will coordinate your handheld GNSS computer, laser rangefinder and other GIS equipment.

With the right solutions, mappers will have a much better chance of organizing the data they collect. They can overcome any potential challenges that could otherwise majorly delay a mapping project.


Contact Duncan-Parnell for Your Mapping Needs

New drone mapping tech offers major advantages for mappers. While these drones can be powerful tools, the tech isn't perfect, and numerous challenges — like wind, site terrain and site location — can make mapping with them much more difficult.

With the right planning and equipment, any mapper can easily manage most of these problems.

Since 1946, Duncan-Parnell has been the trusted supplier to construction contractors, surveyors and designers. We stock the best brands in the geospatial industry, including Trimble® surveying and mapping equipment. We also offer free loaners under warranty for service, free tech support and free documentation and tech tips for our users.

Are you preparing to map a new site? Successful projects start here. If you want to work with us, browse our catalog of mapping and GIS solutions, or contact us today to learn more.


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