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Experts based throughout Quebec offer their opinion regarding the use of a new technology that is revolutionising land surveying, LiDAR.
LiDAR, also known as Light Detection and Ranging which allows terrestrial, airborne, or mobile scanning, and provides detailed digital terrain models and also records landscapes in 3D. Surveys generate data that can be analyzed in software like VisionLiDAR.
LiDAR technology facilitates the measurement of a high density of points covering wide areas. By using it, natural interpretation becomes less ambiguous because of the accuracy of the data, thereby reducing costs compared to a traditional survey type. "Today, scanners are sold for $35,000 (CAD) while, 5 years ago, we bought ours for more than $130,000 (CAD)", said an astonished Alexandre Gagne, President of Geomog, a firm specialized in surveying.
Vital Roy, land surveyor, says that there are "a lot of people who can acquire this kind of device, but surveyors have a great advantage in the positioning. Especially to analyze and talk about the results of a major survey after working into the point cloud. Acquiring a point cloud is one thing, but learning how to analyze the results, that’s another story" he says.
When deciding wether or not to use LiDAR technology, it’s good to think about the adjustment period to associate the digitization based on LiDAR to the interpretation in the field. Moreover, the education of the teams, the use of software to handle many points like VisionLiDAR, and always being informed of the latest technological improvement, to facilitate the development of firms and the market.
"In 20 years, it has evolved so much that it is now possible to generate over one million points per second within 5 mm accuracy" adds Alexandre Gagne. , Mr. Gagne mainly handles LiDAR data in civil engineering. However, he said that the technology can be used by both engineers and land surveyors. "Several tools are used depending on the projects. With VisionLiDAR, we automatically classify points to classes such as ground or building and pick points, allowing us to inventory items such as streetlights, sidewalks, and even remove items that should not be there. So we work less outside, more in our office, and instead of measuring points traditionally, we do it with our mouse in VisionLiDAR" he says. ,
Reaping the results and analyzing them is also the role of Topo 3D, a firm specialized in terrestrial LiDAR in Quebec, which recently acquired a drone. "It helps to bring the technology rapidly into professional services offered to surveyors, engineers, and to the industry" says Cedric Pelletier, , GIS specialist for this young growing company based in Boucherville. "We started as a construction surveying company, and we had to adapt the scanner to perform conventional survey work so we could develop expertise by working on more advanced projects with clients such as Cirque du Soleil" explains , Jonathan Bouffard, Projects Manager at Topo 3D. "In Quebec, there is still a lot of education work to do, and we should start by explaining to the client that it will save him time even if, initially, it costs more than a traditional survey. For example, in the first year, customers, like manufacturers, have saved more because the extracted data contained much fewer errors," justifies Mr. Pelletier.
LiDAR represents a breakthrough for professionals, particularly in terms of security. Jonathan Duguay, junior engineer and GIS specialist at Geo-Plus, says that "it’s no longer obliged to have someone where the point is. The point cloud will have all the objects that you want to make up the inventory or to do the map of the existing conditions."
Indeed, LiDAR is an ideal way to determine the history of landslides, for example. Because of vegetation and different items covering the ground, using LiDAR helps geologists or Land Surveyors to not only see the landslide, but to collect the clues. So investment in LiDAR can prevent or mitigate inevitable natural disasters.
"The vast amount of data collected avoids the need to return to the field, and the number of points allows us to make a digital 3D model almost photorealistic. In statements, on a larger scale, such as roads statements, we can get more points in less time." Mr. Duguay believes how important it is for professional land surveyors to get a scanner, because, "if the team doesn’t have a LiDAR scanner, the firm risks losing some of its market to the civil engineers." For him, "land surveying is changing and the land surveyor must evolve with the market. In 5 to 10 years, it may even be possible to scan from our smart phones, due to the miniaturization of processes used to fetch a large number of points very quickly on the ground."
LiDAR software will also continue to evolve. Therefore, VisionLiDAR already offers automatic objects detection, and automatic virtual surveying. Thanks to these features, vectorization becomes much easier. What is the purpose of Geo-Plus today? Democratize the use of point clouds to use LiDAR technology intelligently and efficiently.
In fact, with VisionLiDAR, it becomes really easy to create 3D representations of existing structures. Now, view and work with the collected data is facilitated into the Point Cloud files. Also, the drawing procedure is becoming faster by working from a real image and referencing object or inserting points into the image.
While using a powerful LiDAR processing software, it becomes possible to work on your picked points previously selected directly on your 2D or 3D drawing. You can also change the appearance or the characteristics of your points by using this method.
The point clouds are created from raw data, which were scanned and represent real objects such as buildings, forests, vehicles, etc. VisionLiDAR can also change the look of your point cloud using classification. This feature will improve your work performance and facilitate your understanding of the point cloud.
The user can change the points density in your cloud by managing the visual rendering of your point cloud and removing noise and unnecessary objects.
By applying a display by color the user can automatically categorize the objects and assign a color. This feature allows to choose between RGB (Red Green Blue) colors, or view the point cloud by normal, intensity, or elevation.
In VisionLiDAR, the user can export objects from the point cloud by detecting them automatically or manually. Other features are also available, like creating contour lines, removing the center line of a cylindrical object, extracting a 2D geometry in a cloud segment.
VisionLiDAR also performs standard editing operations by allowing the user to edit the standard setting of the point cloud. Then, the user can cut, paste, move, rotate, remove, or scale the point cloud. It’s also possible to change the general settings of the point cloud like changing the colors of the classes.
Today, LiDAR technology is helping scientists from different domains to improve their work. It’s the case for archeologists in Cambodia, where Damian Evans, archeologist, is using LiDAR technology to map 2,230 km2 using LiDAR mapping technology. Evans’s project started in 2012 and his goal was to measure every square meter of the chosen area to discover temples buried in the massive city of Phnom Penh.
Previously, in 1970, LiDAR technology was first developed to assist space explorations. Initially used by Apollo 15 to map the surface of the moon, LiDAR technology evolved to become a high-precision technology that can be mounted on a helicopter or on a plane.
Nowadays, with these discoveries, LiDAR technology helps geologists to prevent natural disasters, archeologists to find ancient civilizations, astronauts map other planets, or land surveyors improve their work and security. LiDAR may help find other answers in the future, but for now, it could be the clue to understand how our environment is changing by analyzing the ground of our planet.
And tomorrow, point clouds images will become even more amazing and realistic than they already are today.
Marie Scultore is a French journalist from Marseille, France, established in Montreal, Canada since 2011. After she graduated from University of Montreal in communications, journalism, and editing, Marie collaborated with the Huffington Post, mtl-mix.com, and Radio Shalom Montreal where she presented the news program in 2014. She is currently working as technical writer for Geo-Plus Inc. and is specialized in publishing articles related to geomatics.
A 2.770Mb PDF of this article as it appeared in the magazine complete with images is available by clicking HERE