Drones For Surveying

With rapid technological advancements, drones are being used for a wide range of purposes in lots of different industries. One area of application where companies are utilising the power of drones is aerial surveying. There are many industries that are using drones for their surveying and mapping needs. These include construction, mining, agriculture, forestry, and environmental monitoring. In this article, we shall look at the growing trend of using drones for surveying, their benefits and the best drones for this purpose.

Traditional methods of land-based surveying are time-consuming, expensive and sometimes risky for those who are tasked with the job. Aerial surveying through drones provides an alternative way for companies to carry out their surveying needs without the disadvantages of land-based methods.

The benefits of adopting drone technology for various commercial reasons, including surveying, are huge, and companies that are using drones for their operational needs are reaping the rewards.

Whether you are a drone service provider, a professional surveyor or someone who is interested in the application of drones in surveying, this article will provide an overview of what drone surveying is and how it is benefitting different types of industries.

What Is Drone Surveying?

Surveying is the discipline of determining the position of distinct points and the distance between them on or above the surface of the earth. Surveying plays an important role in many industries where you need accurate maps and measurements of an area of land.

From construction and mining to agriculture and environmental research, companies require a detailed aerial view of sites that they are working on so that they can make informed decisions with regard to planning and implementing those plans.

Traditional methods of land-based surveying require quite a few tools to do the task properly and are quite labour-intensive. It is also time-consuming and can take days or weeks to accurately survey a large plot of land.

Drones provide a cheaper and more efficient method for surveying without compromising on quality and accuracy. In many instances, drones may also prove to be the safer option, as some terrains will be dangerous for land-based surveying.

Drone surveys and mapping are carried done through photogrammetry; photogrammetry is the science of acquiring accurate data about the physical world through images. These images are then stitched together via photogrammetry software, and the end product is resources like maps and 3D models of the area.

From these resources, companies can extract the information they require and make informed decisions with regard to whatever project they are working on.

Benefits Of Drones For Surveying

Drones offer a number of benefits for aerial surveying, these include:

Cost-effective

Using drones for surveying is a cost-effective option as it reduces the need for expensive equipment, such as helicopters or planes, and personnel. Drones offer a rapid and efficient solution for covering large areas during surveys, resulting in a reduction in both time and costs required for the task. They also require less maintenance and operational costs, making them a more affordable option for companies and organizations.

Accurate data collection

Drones are equipped with high-resolution cameras and sensors that can capture accurate data in various formats, including photographs, videos, and thermal images. Drones like the DJI Phantom 4 Pro RTK also come with GPS correctional technology that results in more improved capture of geospatial data. The data collected by drones is accurate and precise, which allows for more informed decision-making and improved project outcomes. This is important in industries such as construction and agriculture, where accuracy is crucial.

Quick data processing

The data collected by drones can be processed quickly and efficiently using specialized software. This allows for real-time results, which can be used to make informed decisions and adjustments to ongoing projects. Quick data processing also reduces the need for manual labour, which can further reduce costs and increase efficiency.

Increased safety

Drones can be used to survey dangerous or inaccessible areas, such as steep slopes, cliffs, and unstable terrain. This reduces the risk of injury to surveyors, as they no longer need to physically access these areas. Drones are also useful in surveying areas that are hazardous due to environmental factors, such as fires or floods, where it may be unsafe for human surveyors to enter.

Flexibility

Drones can be used in a lots of surveying applications, including topographical surveys, construction site surveys, and agricultural surveys. They can be easily programmed to cover specific areas and can adapt to changing conditions, such as weather and terrain. This makes drones a versatile tool for surveying and mapping.

Environmental benefits

Using drones for surveying can reduce the environmental impact of traditional surveying methods. Ground-based vehicles used for surveying can cause soil erosion and other environmental damage, whereas drones have a smaller environmental footprint. Additionally, using drones reduces the need for fuel consumption and the emissions associated with traditional surveying methods, making drones a more environmentally friendly option for surveying.

Industries Using Drones For Surveying

There are many industries that are utilising drone technology for surveying, these include the following:

Construction

According to a survey carried out by cloud mapping company Drone Deploy, the biggest use of drones for their software is from construction companies. Construction companies can formulate a more efficient workflow by adopting drone technology for their surveying and mapping needs. Drones allow construction companies to quickly acquire highly detailed aerial maps of the area they are working on and this will allow them to evaluate lots of different data points. This will help them in every aspect of the decision-making process for the project. From the initial preliminary inspection of the land to see its suitability for construction to

Mining & Quarries

Mines and quarries are dangerous places to work but with the help of drones, many of the risks that come with working on a mining site can be mitigated. Drones are being used to create detailed 3D models and maps of mining sites that will help workers in all aspects of mining operations. From initial mining exploration to calculating stock volume, the use of drones in mining is helping mining activities to become more efficient, less risky and help with saving costs and increase ROI.

Agriculture

The use of drone technology is revolutionising the way farmers are managing their day-to-day tasks. With the aid of different types of camera sensors, farmers can easily survey and map their fields and identify issues such as irrigation problems, pest and fungal infestations and take action as soon as any problems are identified. Data collected through drone surveys are allowing agronomists and agricultural engineers to maximise crop production, use pesticides/herbicides where it is needed, keep waste to a minimum and irrigate the land more efficiently. As drones are cheaper to operate than traditional methods of manned aerial missions, farmers can monitor and assess the health of their crops more frequently and help identify and solve problems quickly.

Environmental Monitoring

With our climate changing and bringing with it unusual weather and increasing the rate of natural disasters like flooding, drought, tropical storms and wildfires, drone technology is helping scientists to better understand how to prevent or mitigate the damages these disasters bring.

Survey Data Captured With Drones

Drones can capture a wide range of data for surveys, including:

Aerial imagery: Drones capture high-resolution images of the survey area from different angles and heights, allowing surveyors to create a detailed visual representation of the terrain, structures, and vegetation. The images captured by drones can be used to develop orthomosaic maps, which are accurate, detailed, and georeferenced maps that can be used to perform measurements and calculations. Aerial imagery can also be used to identify potential hazards, such as slope instability, erosion, or flooding, that can affect the project’s planning and execution.

3D mapping: Drones can capture multiple images of the survey area from different angles and heights, which can be combined to create 3D maps. 3D mapping provides a more detailed and accurate representation of the terrain, enabling surveyors to perform detailed analysis and measurement. 3D maps can be used to perform volumetric calculations, determine slope and elevation changes, and identify potential obstacles or hazards.

Point cloud data: Drones equipped with LiDAR sensors can capture point cloud data, which provides a highly detailed and accurate representation of the survey area’s topography. LiDAR sensors emit laser pulses that bounce off the surface of the terrain and return to the sensor, creating a detailed 3D model of the environment. Point cloud data can be used to create high-precision topographic maps, perform volumetric calculations and detect changes in the terrain over time.

Thermal imaging: Drones can be equipped with thermal cameras that capture temperature data, enabling surveyors to identify heat anomalies and perform energy audits. Thermal imaging can be used to identify energy leaks, detect the presence of water leaks, and locate areas of vegetation stress or disease. Thermal imaging can also be used to identify hot spots in electrical systems, enabling maintenance and repair teams to identify potential problems before they cause damage or downtime.

Multispectral imaging: Drones equipped with multispectral cameras can capture data on different wavelengths of light, providing information on plant health and vegetation analysis. Multispectral imaging can identify areas of vegetation stress, detect invasive species, and monitor crop health. Multispectral imaging can also measure the extent and severity of environmental damage caused by natural disasters or human activities.

Drones offer a versatile and efficient solution for capturing a wide range of data types for surveys. By providing detailed and accurate data, drones can improve the efficiency and accuracy of surveying tasks, leading to better decision-making and improved project outcomes.

Best Drones For Surveying

This is not a comprehensive list, and they are in no particular order, I have listed the multi-rotor drones first because they are the cheapest, while the fixed-wing drones like the WingtraOne and eBee X are significantly more expensive. However, fixed-wing drones have longer flight times, and this makes them more suitable for bigger surveying projects.

If you would like an in-depth analysis of the differences between the most popular drones for surveying, read this case study by Wingtra that carried out a field test to see which one provided the best results.

6) WingtraOne VTOL Drone

A fixed-wing drone that comes with vertical take-off/landing capability, much like a multicopter drone and so there is no need to launch it by hand or any other means. This is a drone that is suitable for large-scale surveying and mapping needs, it has a robust build and can be flown in windy conditions. The drone is compatible with multiple payloads, which include the Sony RX1RII with a full-frame 42MP sensor and the Micasense RedEdge multispectral camera. It comes with an integrated PPK GNSS receiver from Septentrio for survey-grade positional data with the capability to achieve sub-centimetre level accuracy. 

7) eBee X Fixed-Wing Drone

SenseFly’s eBee X is their flagship surveying and mapping drone and is used in a wide range of industries. It’s compatible with multiple payloads including the S.O.D.A 3D camera, the Aeria X with 24MP APS-C sensor, the Duet T thermal imaging camera and the MicaSense RedEdge multispectral camera. It has a maximum flight time of 90 minutes (depending on the payload), which is the best on this list and comes with RTK/PPK modules for greater positional accuracy.

How Accurate Is Drone Surveying?

There are many factors that will influence how accurate a drone survey is; things like the drone’s camera capability, the altitude at which the images will be captured, the requirements of the project, and even the weather and area or target to be mapped/modelled can affect overall accuracy.

Things like GSD, which are heavily influenced by the camera sensor specs, will also affect accuracy as well as the use of GCPs and whether the drone has GPS correctional technology like RTK or PPK.

With all that said, drone surveys have proven to be very accurate, for example, the WingtraOne VTOL drone, which is one of the best drones for photogrammetry, can achieve horizontal accuracy levels of 1cm and vertical accuracy to 2cm.

While DJI Phantom 4 RTK has also been shown to have survey-grade accuracy, achieving sub 3 cm vertical and sub 2 cm horizontal accuracy.

Some situations, like measuring NDVI in agriculture or analysing the health of vegetation, may not require accurate survey-grade measurements, and in those cases, you will not need GPS correctional technology to achieve the highest accuracy.

Best Software For Drone Surveying

There are plenty of drone surveying applications that will help turn your drone data into useful digital assets, although this is not a comprehensive list, the drone mapping applications listed below are some of the more popular ones on the market.

PIX4D

One of the leading software developers for drone photogrammetry solutions, Pix4D’s mapping and surveying apps are one of the most robust on the market. It has a bit of a steep learning curve because of its range of features and the sophisticated nature of the software. However, their support is first class and there is a very active community forum as well as in-depth tutorials. There is a 15-day free trial and then you can either choose a pay monthly subscription plan, a yearly license or a one-off fee.

Drone Deploy 

This a drone mapping and 3D modelling software solution that is suitable for small to large and complex mapping projects. It has a wide range of features and all the data is processed in the cloud so there is nothing to download. The software is compatible with most of DJI’s high-end drones as well as WingtraOne, eBee X and Skydio 2. It serves an array of different industries and the data is easy to read and analyse. There are a lot of helpful guides in the form of webinars, ebooks, a forum and regular blog posts. There are three pricing plans with the option to pay monthly or yearly.

Agiosoft Metashape

This isn’t strictly a tool for just drone photogrammetry, the company has been developing software dedicated to computer vision technology and through years of research, they have gained proficiency in developing algorithms for photogrammetry systems. The software is intuitive, easy to use and comes with a lot of features that will be useful for both amateurs and professional surveyors. There are two versions of this software, standard and professional, the standard version is okay for amateurs who don’t need it for work-related projects, but the professional version comes with a lot more features and is compatible with different type of camera sensors. Both versions come with a free 30-day trial and then a one-time fee.

Site Scan For ArcGIS 

This is a complete end to end cloud-based mapping solution for the AEC and mining industry. The software allows drone operators to plan flight missions, manage flight data and process that data to produce 2D/3D maps. It also has a range of tools that will allow you to make sense of the data and share them with colleagues and clients. If you have a fleet of drones, the software will allow you to properly manage your drone operations safely, efficiently and without any hassle.

PrecisionHawk 

Get access to advanced mapping and flight planning software that also allows drone service providers to manage their fleet of drones in an efficient and safe manner. PrecisionHawk offers more than just a software solution for drone mapping and analytics, as a member you get access to their network of thousands of professional drone pilots who you can hire to carry out your drone mapping needs. PrecisionHawk also provides a consulting service for your drone business and you can even hire their own team for your drone projects. Their software offering is robust and is used in a variety of industries including agriculture, oil & gas, mining and environmental monitoring.

DJI Terra

One of the more recent additions to the drone mapping software market and while it may not be as robust as some of its competitors, it is a DJ product, so you can expect continuous updates and improvements. The DJI Terra allows surveyors to conduct autonomous flight mission and capture aerial data that can be turned into 2D maps and 3D models. It is being used in a wide range of industries including construction, energy, agriculture, mining and government. There is a range of analysis tools to help you with making sense of the data and make better-informed decisions.

Propeller Aero

Founded in 2014, Propeller Aero provides an end to end cloud-based solution for photogrammetry purposes. It’s a robust platform that allows surveyors to process drone data into accurate 3D visuals and comes with a set of analytics tools to make sense of your 3D digital assets. The system is compatible with a range of drones, however, they do advise that their preferred drone is the DJI Phantom 4 RTK.

Maps Made Easy

A cloud-based data processing software for drone photogrammetry, the website may not look as polished as its competitors, but the software does what it says and allows you to turn your drone images in to valuable digital assets for your project. The software can process image data from different types of sensors like RGB, infrared and multispectral and it has an affordable pricing plan that is not subscription-based.

How To Become A Drone Surveyor

To become a drone surveyor, there are a few steps you can take:

• Obtain a drone pilot certification: You must obtain the Part 107 certificate from FAA in the United States or equivalent agencies in other countries. This certification typically involves passing a written exam and a flight test.
• Learn surveying techniques: It’s essential to have knowledge and experience in surveying techniques, such as how to read maps, use GPS, and understand surveying terminology. You can obtain this knowledge through coursework in surveying or by working with experienced surveyors.
• Acquire drone equipment: You will need to invest in a quality drone and equipment, such as cameras and sensors, that are suitable for surveying tasks. It’s important to research and choose equipment that is compatible with the surveying applications you plan to undertake.
• Gain experience: To gain experience as a drone surveyor, you can start by working with established surveying companies or collaborating with other professionals in the industry. This will give you exposure to different surveying projects and allow you to develop your skills and knowledge.
• Stay updated with industry developments: It’s essential to stay updated with industry developments, new technology, and regulations governing drone use in surveying. This can be achieved by attending industry conferences, taking courses, and networking with other professionals in the field.

Becoming a drone surveyor requires a combination of technical knowledge, practical experience, and a commitment to staying up-to-date with industry developments.

Photogrammetry vs LiDAR

Creating digital 2D maps and 3D models through images captured by drones is done through a process called photogrammetry.

Photogrammetry is the science of obtaining accurate data about the physical world by capturing and interpreting digital images through different types of camera sensors. These image data can then be processed through photogrammetry software to obtain digital assets like 2D maps, 3D models, point clouds and other types of aerial maps.

It is the most popular and cost-effective way to survey and map areas of land and physical objects.

An alternative to photogrammetry is a system called LiDAR which stand for light detection and ranging. LiDAR is similar to SONAR and RADAR, it scans the area below by rapidly firing laser pulses from its sensor and then calculates how long it takes for the pulse to reflect back to the sensor.

It is a decades-old technology that has only recently become suitable as a payload for commercial drones.

When LiDAR data is processed you get a detailed point cloud that is accurately georeferenced with each point having 3D spatial coordinates. The result is a 3D visualisation of the area or object that has been scanned.

The advantages of LiDAR over photogrammetry are several, for example, laser pulses can penetrate areas of land that are populated with dense vegetation and provide an accurate visual representation of the area below. This is not possible with photogrammetry because images need a lot of light to capture all of the data for a photo.

Also, LiDAR is the best option if you are required to map in a low-light environment or at night time because, unlike photogrammetry, it does not require an outside light source.

LiDAR data is tougher to decipher if you are not a GIS professional, whereas a 2D map or 3D model from photogrammetry is easier to understand, even for people with little experience with mapping.

Both methods have their pros and cons; however, the biggest deciding factor for most companies will come down to cost, and in that case, photogrammetry is the better option as it is much cheaper than LiDAR.

Final Thoughts

In conclusion, using drones for surveys offers numerous benefits, including increased efficiency, accuracy, and cost-effectiveness. Drones can provide surveyors with detailed and accurate information about the area by capturing a wide range of data types, including aerial imagery, 3D mapping, point cloud data, thermal imaging, multispectral imaging, and survey markers. This enables better decision-making and improved project outcomes across various industries, from construction and mining to agriculture and environmental management. As drone technology evolves and improves, its use will become even more widespread and integral to the surveying process.