Article | Landpoint

How Does LiDAR Work, and What Are Its Limitations?

July 21, 2020/in Article /by Seven Atoms

LiDAR is one of the leading options for surveying today, and it’s easy to see why. As a technology, it’s advanced, highly accurate, and fast. Compared to competing technology, it’s more effective and accurate a greater percentage of the time. To fully understand the benefits of LiDAR, you need to understand how LiDAR works, and why new Unmanned Aerial Vehicles (UAVs) technology is helping it really take off.

What exactly is LiDAR? How does LiDAR work?

LiDAR releases very fast pulses of light towards a target and then measures the amount of time it takes for that light to travel back. As a LiDAR unit moves, usually on an aerial vehicle, it’s able to continuously scan an area using these small bursts of light to see how the terrain is changing around it. LiDAR units will take many points of data, which are then turned into a 3D mesh.

For LiDAR to work effectively, its data must be analyzed. LiDAR data on its own is simply a number of disconnected points in space. But once processed and analyzed, this data will form a consolidated topographical map.

LiDAR data is often gathered via sensors placed on vehicles such as UAVs (drones), helicopters, and planes. The method by which LiDAR data is captured does have some impact on its quality. Planes fly much higher than drones or helicopters, and consequently the data will not be as high resolution as it otherwise could be. However, that also means data can be captured much faster.

LiDAR differs from the other major surveying method, which is photogrammetry. Under photogrammetry, photos of terrain are taken in quick succession, also often from an aerial vehicle. These photos are then analyzed to create a 3D model. Photogrammetry is not as accurate because it relies on 2D pictures to create a 3D model, but it is fast and cheap, and it does produce models that are usually fairly easy to understand; unlike LiDAR, these photos have color and realistic texture, so it is easy for the untrained eye to recognize things like fields, rivers, and roads.

Oil & Gas Facility

Laser Scan Oil & Gas Facility Model

Power Facility

Laser Scan Power Facility 3D Model

Production Skid

Laser Scan Production Skid 3D Model

What is a LiDAR drone?

LiDAR can be used on any aerial vehicle, but drones are becoming far more popular. A LiDAR drone is more maneuverable, able to capture higher resolution images, and can be deployed very quickly. Comparatively, other methods of LiDAR scanning require additional permits and licenses, and there is always the risk, no matter how minor, of something happening to a manned aerial crew.

What are the major benefits of LiDAR?

There’s a reason why this technology has seen such widespread adoption. The benefits include:

It’s fast. LiDAR captures quick bursts of light and can scan virtually as quickly as the aerial vehicle is able to move. Large swathes of land can be covered by LiDAR units.
It’s accurate. When paired with UAV, LiDAR scans can be conducted very low to the ground, taking high-resolution images of even very complex terrain. LiDAR scans can be taken in areas that would normally be too dangerous to survey, and drones are able to operate with precision to get the most accurate scans.
It’s in-depth. Photogrammetric imaging won’t show you what’s beneath brush or cloth, but LiDAR can. LiDAR can see through thin cloth and overgrown plants and leaves, thereby providing better topographical data.

However, there are few situations in which a LiDAR drone won’t be the optimal method for surveying.

Are there any limitations to LiDAR?

Every technology has its limitations, even LiDAR. Though LiDAR has many benefits, there are also some downsides, which is why some projects choose to use photogrammetric imaging instead. A lack of color and texture means it can be difficult to interpret LiDAR data without training or additional pictures overlaid on the data.

LiDAR also requires in-house processing to get the most accurateresults. Because LiDAR data is very complex, outsourcing data analysis can lead to inaccurate data. Further, LiDAR is more expensive than other solutions like photogrammetry.

It can be beneficial to work with a company that offers both LiDAR and photogrammetric imaging. When used together, LiDAR and photogrammetric imaging can be extremely effective.

Are you interested in learning more about the benefits of LiDAR? Do you want to know the differences between LiDAR and photogrammetry? Contact the experts at Landpoint.

Why Accurate BIM is a Construction Company’s Dream

July 14, 2020/in Article /by Seven Atoms

From preserving historic museums to developing new condominiums, building information modeling (BIM) is changing the face of architecture, design, and construction. Through accurate BIM, construction companies are able to plot out their projects in virtual space, anticipating issues, reducing re-works, and otherwise improving their return on investment.

Here’s why accurate BIM is a construction company’s dream.

BIM Construction = Reliable Construction

First, how is BIM used in construction? The construction industry has always relied upon data to make decisions. Recent advancements in technology have made the construction industry far more reliable. Decades ago, construction companies found themselves suddenly able to improve upon their product cost and deadline management through the power of computers.

In the very early days, having spreadsheets available made it easier for construction companies to produce more accurate bids. From there, construction planning solutions made it possible to streamline and improve upon the entire process, from start to finish.

Today, BIM is making construction data even more accurate. Construction companies are now able to plan their projects down to the millimeter, from showing clients how the finished product will look, to determining how different materials may interact with the surrounding environment. The better the data model, the less likely it is that companies will encounter surprises, and the better the company can plan for the future.

Improved Data Means Reduced Reworks

The construction industry spends approximately $178 billion a year on reworks — and that doesn’t include the cost of unsatisfied customers and damaged reputations. To a certain extent, some reworks are going to be expected in any project. But with better data, reworks can be vastly reduced.

Modern building information modeling is so advanced that construction companies can even assess a project’s interactions with the surrounding environments. BIM is becoming an important part of solar panel farms and wind farms. They can determine what the solar or wind output will be depending on the weather and the season.

Furthermore, building information modeling can be used to keep clients engaged, and to ensure that clients have a picture in their mind of the completed project at all stages of development. Clients will be able to determine whether there are things that don’t work for them at the beginning of the project, instead of at the end, and consequently are less likely to request changes.

Example of 3D model made using BIM
3D model of construction skid
3D model of an abandoned hardware building

Alleviating Environmental Concerns for New Construction

Today, construction companies are more conscientious than ever about the impact that their buildings can have on the surrounding environment. Will glass potentially reflect damaging rays into the surrounding area? Could a change of water flow increase the natural erosion?

Construction companies aren’t just able to simulate the environment’s impact on the buildings, such as seasonal sunlight changes, but also the building’s own impact on the surrounding environment. This goes a long way towards building construction projects that will last a long time and that will make responsible use of the surrounding land.

Making It Easier to Collaborate with Other Teams

Through BIM, construction companies are able to identify potential conflicts between systems. Plumbing, electrical, and HVAC systems can all be compared before any work is done. Teams, even those working for different contractors, are able to share data and models. This means they can collaborate and communicate with each other more effectively, since they will always be working off the exact same data, rather than potentially using different versions.

With BIM, construction companies can share data and documents through the cloud, and this information can remain persistent throughout the job. At the same time, the construction company can lock down and control changes, so there isn’t a risk of others overriding the essential data.

Keeping Records for Completed Projects

Data is eternal. There’s a reason why BIM has been used on historic buildings: to preserve them forever. Through BIM, construction companies are also able to keep thorough records of their completed projects. Not only do they have the plans, but they can also use surveying to create models of the construction as it is completed.

Once the project is done, the company still has a complete record of the work, whether it’s needed in the future for renovations, or whether they simply want to make sure that their client has an archive of their project for legal purposes.

Adapting to BIM Construction

Business information modeling is constantly improving. It’s expected that the coming years are going to see some dramatic advances in the accuracy and ease with which BIM can be used.

So why are some construction companies not yet using BIM? The use of BIM requires new systems and processes. Construction companies need to explore new advanced technologies and platforms, and engage in training employees. This takes time.

A partner can help. For more information about BIM and how to collect it, consult with the experts at Landpoint.

3D Architecture Modeling: How a Video Game Could Save Notre Dame

July 8, 2020/in Article /by Seven Atoms

When the Notre Dame cathedral burned in 2019, the entire world watched with rapt, horrified attention. The Notre Dame cathedral has long been a major historical treasure. Since 1163, it’s been known as a superb example of architecture. It has stored valuable works of art and antiques, and has become one of the most common tourist destinations in the world.

But through technological advances such as 3D architecture modeling and drone 3D mapping, the Notre Dame cathedral can still yet be saved – or, at least, restored. Here’s how a video game, of all things, may help bring back this historical building, which is expected to have its reconstruction completed by 2024.

3D Scanning for Historic Architecture

3D architecture modeling is already one of the top methods of preservation for historic buildings. Buildings can be 3D scanned and the surrounding areas surveyed for many reasons, with one of the most critical being if they are damaged or destroyed in the future. If they are damaged, these models can be used to create period-accurate repairs. If they are destroyed, these models can live on forever in the form of a digital museum.

But it wasn’t a historical preservation society that took scans of Notre Dame. Instead, it was a video game, Assassin’s Creed: Unity, using drone 3D mapping. This unexpected source could become an incredibly important resource moving forward.

Video Games and Historic Art

Assassin’s Creed is a long-running video game series that is well-known for constructing highly accurate virtual reproductions of ancient locations. Players of the Assassin’s Creed series have been able to run through historic Egypt, Italy, Greece, and more.

Players are sometimes even able to view buildings at different stages of development, due to the game’s time-traveling plot. Each location is met with descriptive text that explains the historical, architectural, and other importance of the building. Of course, it’s also a game about assassins and aliens, but that part is less relevant.

During its development, Assassin’s Creed: Unity creators conducted a very accurate recreation of the Notre Dame cathedral. Since then, many have discussed how this digital model could be used to accurately reconstruct the cathedral itself. This isn’t as unusual as it may seem. The video game industry has been making rapid strides in 3D technology, just as the movie animation industry has been.

It’s also not unusual to use a video game. In the past, photographs, drawings, and other media were often used to aid in reconstructions. While no one piece of material can be thought to be the last say in a reconstruction, being able to see the commonalities between media gives a fairly clear idea of the original. For example, an archway seen on five photographs and ten drawings is likely to be fairly accurate.

Today, accuracy goes beyond the human hand and eye, and into the realm of digital survey and drone 3D mapping.

Oil & Gas Facility

Laser Scan Oil & Gas Facility Model

Power Facility

Laser Scan Power Facility 3D Model

Production Skid

Laser Scan Production Skid 3D Model

BIM and Historic Sites

Today, it’s a game that could be saving a major historic site. Tomorrow, there could be a vault that contains all the major historic sites in the world. Business Information Modeling (BIM) — the ability to capture and preserve information about a building and the surrounding area — is a non-disruptive, highly accurate way of taking snapshots of time.

Imagine a world in which every historic site has a corresponding accurate 3D model. It can never be fully lost. If an earthquake occurs and the building falls, the building can either be completely reproduced, or it can be visited in virtual space. Even if the building is still there in all its glory, BIM can be used to create simulations for those who cannot see it in person. BIM can even be used to determine how changes in the surrounding environment could eventually impact the buildings.

Think about historic Venice. Rising waters and continued degradation mean that Venice and its most historic buildings are in danger. BIM wouldn’t just immortalize these, it could also be used to simulate how long Venice will last under the current conditions, and what could potentially be done to slow the degradation.

BIM is truly an excellent opportunity to save priceless historic locations. While nothing can replace the original buildings, and everything held within them, BIM can make it possible to get extremely close in terms of historical accuracy. Even as buildings may fall and crumble, BIM creates an eternal digital world through which these great works will always exist.

Image Credit – Softonic

Surveys at Scale - How Landpoint Tackles Survey Projects of Any Size

Aerial Survey Companies & the Types of Surveys They Offer

April 4, 2019/in Article /by Jill Souter

When looking for an aerial survey, you should be aware that there are three major types of survey you can invest in: drone, helicopter, and plane. While the actual land surveying technology may be separate (either LiDAR or photogrammetric), the method through which the data is captured will have a significant impact on the cost of the survey, as well as the accuracy of the survey. Here’s what you need to know about drone, helicopter, and plane surveying.

Drone Aerial Survey

Drones (UAVs) have many advantages over traditional surveying technologies—which is why UAV and LiDAR scanning has become an industry standard. They can perform land surveys quickly and close to the ground, delivering high resolution images within just a few hours. UAVs are not manned, and therefore they don’t carry with them a significant risk of potential injury. They are less expensive than other options because they are unmanned and due to the lower cost of the technology. UAVs can navigate into virtually any area with little preparation.

However, there are a couple of disadvantages to drone-based technologies. UAVs may not be able to fly in windy environments, as they are lightweight. Further, UAVs are party to a number of regulations and restrictions. While these regulations are still being explored, they can occasionally present a barrier.

Helicopter Aerial Survey

Helicopters are able to hover while using LiDAR technology, remaining stable even in bad weather. They are often desirable over ground surveys because helicopters can go virtually anywhere. Compared to airplane surveys, helicopters can fly lower and therefore acquire higher resolution imagery. Helicopters are more maneuverable in high winds than drones, and they also aren’t subject to the same types of regulations.

In terms of negatives, a helicopter does still involve a flight crew, which can be potentially dangerous. If a helicopter does crash, people could be seriously injured and a project could be delayed. Helicopters are more affordable than airplanes, but they are not as affordable as UAVs. Operational delays may also factor in, as manned crews will need permits and licenses to fly.

Airplane Aerial Survey

During an airplane survey, an airplane uses LiDAR technology as well as GPS coordinates to very quickly scan an area as it passes above. Airplane LiDAR surveys are very fast and can be effective over virtually any type of terrain. Airplanes tend to be a superior way of getting scans over very large areas quickly, such as when doing preliminary surveys before a site is selected. Airplanes also cannot be dissuaded by issues such as inclement weather or high winds.

Of course, there are also some disadvantages to conducting LiDAR via airplane. Airplane LiDAR tends to be very expensive, as not only do you need to pay for the aircraft and the LiDAR, but you also need to pay for the crew of the plane as well as the fuel. Further, airplanes need to fly fairly far away from the ground to remain safe, which lowers the resolution and accuracy of the scans. Like helicopters, airplane scans may also be dangerous to the crew.

Conclusions

Each type of survey has pros and cons, depending on the project that you’re completing. In general, if the area to be surveyed isn’t party to anti-UAV regulations or high winds, a UAV will be the preferable option. If there are high winds or other dangerous weather, an airplane or helicopter may be better, as budget allows. A UAV will be able to get closer than an airplane at a reduced cost, but a helicopter provides a solid middle ground between the two.

Consulting with a land survey company can help you determine which type of survey technology is best for you. While there are many companies that have recently opened offering UAV-based surveys, Landpoint is one of the few surveying companies that offer all three types of surveys. For more information about the types of surveying available, contact Landpoint.

6 Considerations When Selecting a Wind Farm Surveyor

April 2, 2019/in Article /by Jill Souter

When conducting a wind turbine survey, time and accuracy is of the essence. If your land survey is delayed, then your project will be delayed. Wind farms rely upon the accuracy of their land surveys to plan out the most efficient, effective routes for their turbine placement. The more accurate a land survey is, the more productive the wind farm will be. All of this makes selecting the right wind farm surveyor critical.

Here are six important questions to ask.

1. Are They Able to Cover Large Distances Quickly?

A ground survey is going to take a lot of time—time that a wind farm project may not have to spare. Wind farms tend to be over very large expanses of land, land which can be overgrown. If the environment is right, drone-supported LiDAR technology can be used to scan an entire project in as little as a few hours, depending on the size of the project. Airplane-supported LiDAR surveys can complete large surveys even faster—ideal early in the process of site selection.

2. What Methods of Scanning Do They Provide?

Many companies provide drone, helicopter, or airplane scanning, but very few provide all of these types. When looking for a wind farm surveyor, ask about the options the survey company has available. Depending on the size of the project and the weather, you may need to pivot between types of survey. If the area is windy, a helicopter or airplane will be better than a drone; if there are large areas to cover, an airplane will be better than a drone or a helicopter. Your needs for survey may change, depending on whether you’re using the survey for initial site location or turbine placement.

3. Can They Provide 3D Data?

Accurate data is absolutely critical to the success of a wind farm project. Wind farm projects demand a certain type of environment; once surveys are completed, a wind farm is going to need to be prepared for expensive, heavy, and advanced wind farm equipment. Landpoint’s LiDAR technology can provide up to 1 centimeter to pixel resolution. These LiDAR scans can then be used to create a 3D model for simulations and modeling. The entirety of a wind farm project can be simulated and tested before it begins.

4. Are They Able to See Through Overgrown Regions?

LiDAR has a clear advantage over traditional, photogrammetric analysis: it can see through overgrowth wires, and even thin cloth. If you need high resolution data that can cut straight down to the ground topology, then LiDAR is the best choice. Wind farms need to be placed extremely accurately if they are to be effective, and unexpected changes in elevation will need to be addressed during the process of development. Photogrammetric analysis can only map the topology that is visible to cameras, while LiDAR can go beyond the naked eye.

5. Can They Process and Analyze Land Survey Data Quickly?

If a surveyor provides in-house data analysis, they can likely produce land survey data quickly. If a surveyor needs to outsource their data analysis, it may take much longer. Relying upon a third-party to analyze the data that is produced by the survey can lengthen the amount of time a project takes, as both parties will need to wait on the other. It can also increase costs, as an organization that develops its data in-house will be able to reduce the total amount of overhead needed for each service.

6. Are They Able to Provide Both Initial and Monitoring Surveys?

Initial land surveys aren’t the only type of survey a wind farm may need. Monitoring surveys, when paired with sensors, are an easy way to quickly identify maintenance or repair issues with wind farm equipment. Through GPS tracking, the drones can immediately report the exact position of any identified issues. Drone surveys can save a company money when compared to on-the-ground surveys, which can lead to having more surveys completed and better maintenance overall.

Through aerial drones, planes, helicopters, and LiDAR, the right wind farm surveyor will be able to quickly survey a large wind farm plot with exceptional accuracy. At Landpoint, not only is advanced LiDAR technology used to produce high-resolution topological data, but drones and sensors can be used for both land surveys and continued monitoring services. For more information about the advantages of LiDAR, contact Landpoint.

Aerial Mapping With Drones – Does It Make Sense For Your Project?

March 28, 2019/in Article /by Jill Souter

Drone technology is the latest in land surveying, but does it make sense for your project? If you’re looking for an aerial data service and considering the use of UAVs, you may want to learn more about the UAV process and whether other options would be better for you. Here are a few questions to ask yourself about your project before you commit to any type of aerial surveying.

Questions to Ask When Selecting an Aerial Data Service

How quickly do you need the survey?

If you need your survey fast, use a drone. Drones are fantastic if you need a fast turnaround time. Not only can they be deployed almost immediately, but they will be able to scan and report the data back quickly. And at Landpoint, your data will also be analyzed quickly in-house. Aerial mapping with drones is typically the fastest option when you have relatively small areas that you need to be surveyed.

What are the current weather conditions?

If there are high winds involved, then you may not be able to send out drones. Drones cannot function in high wind, significant rain, or storms, because they are light and get blown around. In high winds, helicopters usually make sense. They are more affordable than airplanes, but they can stabilize themselves even in fairly poor weather (UAV technology has advanced to the point where light winds are usually not an issue).

How large an area do you need to cover?

While drones can cover fairly large areas quickly, a very large area may call for an airplane survey instead. Airplanes can cover large tracts of land faster, which is important for general purpose surveys of significant chunks of property. However, since an airplane does need to fly higher than a drone, you a may not get as high-resolution imagery as you would using drone technology.

What is the terrain like?

UAVs, helicopters, and airplanes all do well with rough terrain. When you need detailed data from, say, inside a canyon, however, then drones are going to be the best bet. Drones can survey close to the ground and can take detailed, high-resolution scans of rugged areas. While the same LiDAR technology can be used on both helicopters and airplanes, they just can’t reach as close to the same terrain and consequently can’t deliver as accurate results.

How much have you budgeted for the survey?

If you want to save money, aerial mapping with drones makes sense. Drones are the most affordable type of survey out there. Both helicopters and planes naturally cost more because they involve larger crew as well as more substantial risk, as the crew could potentially get injured if the aircraft gets damaged. Regardless of the cost savings, though, the technology that is used to capture the survey data is separate; a reduction in the budget doesn’t mean a reduction in quality.

Are there any anti-drone regulations in the area?

Some areas have enacted regulations against drone flight. If drones aren’t allowed to fly in the area that you want to survey, it makes more sense to use either a helicopter or an airplane. With some anti-drone regulations you may be able to get a permit for the flight and the survey; with others, it may just be faster to choose a different option.

There are many situations in which drones are the best option, but don’t forget that there are other choices, too. While there are many drone companies that have emerged within the last few years, there are fewer companies that offer all three different types of aerial survey. At Landpoint, drone, helicopter, and plane surveys are all available, all with high levels of reliability, accuracy, and speed. For a consultation regarding our aerial data services (and to find the option that’s best for you) contact Landpoint today.

Aerial LiDAR: What Are Your Options?

March 26, 2019/in Article /by Jill Souter

Aerial LiDAR is undoubtedly one of the fastest and most accurate methods of completing a land survey. However, there are multiple ways that you can acquire aerial LiDAR data. An aerial LiDAR scan can be completed through the use of helicopters, planes, and drones. Here’s everything you need to know about selecting the right option for your project.

The Three Types of Airborne LiDAR

LiDAR scans can be used from multiple airborne vehicles. Planes, helicopters, and drones can all be used to capture LiDAR information, but there are differences in the ways that they will capture this information. While UAV drone technology has proven to be the most versatile all around, there are also scenarios in which helicopters or planes may be preferable.

Budget

Drone. A drone is going to be the most affordable method of aerial LiDAR by far. Drones are less expensive because they don’t require a crew to run them.
Helicopter. Helicopters are less expensive than planes but more expensive than drones. While they do require a crew like a plane, a helicopter itself is generally less expensive to operate.
Plane. Planes are the most expensive aerial LiDAR option. Not only do they require a crew, but they may also require some permits or licenses to run.

Safety

Drone. A drone is an unmanned craft, which means even if it does experience issues, it won’t cause injury to a crew. This makes it the safest option for an aerial survey, and is one of the primary reasons it has become a popular method.
Helicopter. Contrary to popular belief, helicopters are only slightly more dangerous than planes—though this depends a lot on the environment they are flying in. However, both helicopters and planes can be dangerous because they have a crew which can get injured.
Plane. As mentioned, both helicopters and planes are substantially more dangerous than drones. That being said, it isn’t always a significant risk: most planes and helicopters will never experience issues. Safety is a major concern with any equipment, and a plane can malfunction more spectacularly than a drone.

Accuracy

Drones. Drones have the highest levels of accuracy because they can fly the lowest of the aerial options. The lower they fly, the more detailed their scans and the higher their scan resolution.
Helicopters. Not only can helicopters fly lower than airplanes, but they can also hover. This means they can produce higher levels of accuracy than planes, even if they may not meet the accuracy of a UAV.
Planes. Though a plane does need to be at a higher elevation (and therefore produces lower levels of accuracy), these levels of accuracy are usually still significant enough to be suitable for most applications.

Weather

Drone. A drone cannot fly in exceptionally poor weather conditions or in high winds. While there’s always the possibility of waiting, it can make it difficult to survey areas that are frequently windy.
Helicopter. Helicopters are able to collect LiDAR data in bad weather, though very bad weather should still be avoided. Helicopters can hover even in high winds.
Plane. Planes can collect LiDAR in nearly every type of weather, as the weather does not impact an aircraft the same way it might impact a drone or helicopter. However, it can interfere with some types of scanning.

Speed

Drone. Drones can report back data in a matter of hours, primarily because they can be deployed quickly and complete a scan fast. This can be important for projects which have close deadlines.
Helicopter. With helicopters as well as planes, requisitioning and prepping the equipment and crew may take longer. However, once in the air, a helicopter survey will be quite fast.
Plane. Once the crew and equipment have been prepared, a plane survey should be quite fast. In fact, over large areas, planes are usually the fastest way to get an aerial survey done.

Choosing a Method of Aerial LiDAR

By assessing the five factors above, you can decide whether you need drone, helicopter, or aerial LiDAR. Regardless, you’ll get high resolution imagery that has been plotted out by advanced laser scanning technology. Aerial LiDAR is always going to be an effective option; the method is just going to alter how safe, fast, and expensive the process is going to be.

Are you still wondering whether aerial LiDAR is right for your next survey? Contact Landpoint to find out more about the benefits of aerial LiDAR and the differences between different types of airborne LiDAR technology.

Understanding Drone Survey Accuracy

January 29, 2019/in Article /by Jill Souter

Everyone knows that drone surveys are faster and safer, but are they really more accurate? UAV mapping technology has made some substantial strides within the past decade and now encompasses a huge industry. From small, mobile “toys” to hardy, military-grade equipment, drones are now used throughout many sectors and for many purposes. How can you compare drone survey accuracy to the accuracy of older surveying methods?

What Does “Accuracy” Mean?

When it comes to land surveying, accuracy can mean multiple things. As an example, older photogrammetric technology is occasionally said to have higher resolution because it takes a series of high-resolution photos and creates a 3D plane from these photos. However, this great level of resolution isn’t always meaningful because it doesn’t necessarily correlate to useful 3D point data. Comparatively, advanced LiDAR technology may not have the same pixel size, but contains many times the amount of useful topological data.

Rather than using resolution or pixels, accuracy in a ground survey is usually associated with the accuracy to which the 3D data can simulate the real-world. In other words, how accurate the measurements are, both absolute and relative to the surroundings and the site itself. This is understandably more complex; while anyone can say that you can create scans of a specific resolution, it requires a lot of real-world data to say that you create scans of a specific level of accuracy.

How Do Drones Determine Their Position?

Drones can scan the ground with highly precise technologies such as LiDAR. These technologies send out hundreds of thousands of pulses per second to map topological differences relative to each other, contributing to a very high degree of relative accuracy. However, absolute accuracy is determined using GPS. GPS isn’t always able to produce a completely accurate relative position, and consequently, further data analysis is often required.

This data analysis is often supported through the use of ground control points. Ground control points create fixed and known points that the drones can use to position themselves and continually correct their own positioning. Understandably, these ground control points must also be carefully positioned for the right level of accuracy.

Drones may be adversely impacted by things such as weather conditions, terrain profiles, and, of course, the drone hardware. Hardware matters when hiring a drone surveying company, as the more advanced the UAV mapping hardware is, the less likely the drones are to be influenced by things such as poor weather conditions and difficult terrain profiles.

How is the Accuracy of Drones Tested?

Drone survey accuracy is tested through margins of error when drone data results are compared to real-world information and conventional surveying methods. By testing drone accuracy against known sets of data, operators and surveyors can determine how accurate the drones are as a whole. From there, they can publish how accurate their surveys are. The accuracy level must be reproducible to be claimed. When accuracy is reported for a drone survey, it is reported using the exact same accuracy measurements as any other type of surveying. A drone survey that boasts 2 CM accuracy will be as accurate as another type of survey that boasts 2 CM accuracy.

Best-in-class UAV mapping technologies can currently resolve surveying sites to 1 CM of accuracy. This accuracy is extremely competitive with other technical models and is supported through the use of careful real-world analysis and testing. While drone survey accuracy can be influenced through a number of factors, the right drone surveying company can carefully control these factors and create reliable, reproducible results.

Everything You Need to Know About UAV LiDAR Mapping

January 28, 2019/in Article /by Seven Atoms

If you’re currently planning a land survey, you may be wondering about the advantages and disadvantages of LiDAR mapping technology. Through UAV LiDAR mapping, environments can be mapped down to extraordinary detail, even through brush and foliage. UAV LiDAR mapping is the most technologically-advanced and convenient solution today and understanding the technology behind it is critical to understanding its core benefits.

What is LiDAR mapping technology?

In a nutshell, LiDAR:

Uses laser light to determine the distance between a sensor and an object, whether on the ground or from the air.
Penetrates through minor obstructions, which may include tree canopies, man-made objects, and brush on the ground.
Creates a point cloud, which can then be used to create a detailed terrain and object models.

LiDAR (“light radar”) mapping technology uses multiple pulses of laser light to determine the distance between a sensor and an object. These light pulses are sent out extraordinarily quickly – up to millions of points a second. Sensors use the amount of time that it takes for these pulses to be bounced back to determine how far away an object is.

In LiDAR surveying, laser lights are bounced from above along the terrain to create a 3D model of the terrain, which is extremely detailed. As laser light can go through objects such as tree foliage and brush, LiDAR can be used to create an accurate model of terrain even if the terrain is over-grown or developed.

LiDAR has been in use since the 1960s, and it is currently the most accurate form of creating models of digital elevation. Some forms of LiDAR can even be used to map terrain under water, such as riverbeds and shallow lakes. LiDAR is often used in conjunction with advanced software solutions, which determine the type of objects that are being scanned by the LiDAR in addition to just elevation.

Through the use of advanced software platforms, LiDAR can be used to not only record elevations but also accurately identify things such as street lamps, power lines, or even birds. Software systems compare different elevation studies with potential items on the ground and are consequently able to identify the difference between things such as man-made items and things such as bushes.

LiDAR is used throughout industries such as agriculture, archeology, geology, and even law enforcement. The most popular alternative to LiDAR is another technology called photogrammetry.

What is the Relationship Between UAVs and LiDAR?

Unmanned aerial vehicles (UAVs), often referred to as drones, can be deployed over virtually any terrain for the purposes of fast scanning.
Unlike manned aerial vehicles, UAVs do not present safety hazards to operators and can be used low to the ground.
UAVs are cheaper and faster than manned aerial vehicles, saving companies both time and money on their surveying.

LiDAR can be used by land as well as via the air. When used by land, for instance, LiDAR can be used in the “speed guns” that police use to determine whether someone is speeding. For the mapping of terrain, however, LiDAR is almost always used via an aircraft. These aircraft can be manned or unmanned.

When used in conjunction with a manned aircraft, LiDAR scans are more costly, less precise, and more dangerous. Multiple individuals need to be on a manned aircraft, as both the craft and the scanner must be operated. Aircraft can crash, which could cause injury or even death to those onboard. Further, manned aircraft cannot fly low to the ground, which means their scans are of lower resolution.

Comparatively, Unmanned Aerial Vehicles (UAVs) are able to fly with a single operator, can fly low to the ground, and will not injure anyone if they crash. UAVs can be deployed to cover large areas of an environment at once and can quickly create high-resolution scans, which can then be directly imported into the relevant software.

Used together, UAV and LiDAR technology forms the most powerful surveying tool presently available.

What is the difference between LiDAR and Photogrammetry?

Photogrammetry is a method by which a large number of overlapping photographs of a region are taken and then processed to determine the measurements between multiple points. It is a fast and affordable method of mapping large areas of land quickly.

As photogrammetry uses 2D objects to interpret 3D space, it can only produce many of the same deliverables, depending on the terrain. With big data and new analysis tools, photogrammetry can be accurate enough for smaller projects or projects that need to cover a very large expanse at a lower than average cost. This is why photogrammetry is often used for projects that need to map entire cities.

Photogrammetry has one technological advantage over LiDAR: it also provides seamless imagery of the mapped area. As it relies upon photographs, it is capturing the color and the texture of the terrain, which means that photogrammetry maps can be more understandable to the human eye even if they are less accurate overall. LiDAR scans can still be textured, but these textures may not be as accurate.

However, this advantage is often side-stepped by using photogrammetry and LiDAR together, to create accurate 3D data that has also utilized photogrammetric imaging. This process is both more involved and more expensive but can produce both human-readable and machine-readable models.

As photogrammetry requires that the 3D space be derived from 2D images, it produces fairly low-resolution results and often cannot identify smaller or thinner objects. Power lines, for instance, are often not viewable through photogrammetric data. Finally, photogrammetry does work on photographic technology, which means photogrammetry has to be completed during the day and it has to be done during the appropriate weather conditions. UAV LiDAR mapping has fewer environmental concerns.

In terms of cost, photogrammetry is substantially less expensive than LiDAR, and it can also be used with UAV technology. In fact, UAV technology remains the most effective way to complete surveying regardless of wither LiDAR or photogrammetry is being used. However, this cost savings may not be substantial if it comes at the ultimate cost of a delayed project or mistakes being made.

LiDAR captures the data that is necessary for modeling terrain; this is highly specific, highly technical data that needs to be worked on by professionals. Photogrammetry produces large volumes of photographic data, which then needs to be parsed using the appropriate software.

Does Your Survey Need LiDAR or Photogrammetry?

Both of these technologies are still in use today for an important reason: they’re both useful tools given the right circumstances.

If you’re wondering whether your survey needs LiDAR or photogrammetry, you can ask yourself the following questions:

Is there anything obscuring the terrain from above? If there are trees, bushes, or manmade objects above the terrain, photogrammetry isn’t going to be able to penetrate down to get an accurate elevation.
Is there a reason why you would need full-color maps? If your project needs accurate terrain color, you may need to use photogrammetry or to combine photogrammetry with LiDAR.
Is there a need to model small objects? Photogrammetry cannot pick up small objects, such as power lines, which makes it unsuitable for projects that need higher resolution.

Other than specific use cases, LiDAR is generally the better tool — if the budget is there for it. Many people believe that the future of surveying may actually be in combined LiDAR and photogrammetric mapping, but few argue that LiDAR isn’t the superior technology when the two are compared.

LiDAR mapping technology is still more expensive than some alternatives, but the use of UAV can make it a faster and more cost-effective solution overall. In many projects, LiDAR may be able to pay for itself in terms of time and cost saved — and, as it becomes an industry standard, the costs related to it have been steadily decreasing. For those who need accurate, fast, and safe results, the best choice is almost universally UAV LiDAR mapping, though you may still want to consult a professional land surveyor to find out which option is best for your specific project.