How Construction Changes with Point Cloud Scanning! The 3D Construction Revolution Brought by LRTK

Introduction: Why "3D Construction" Now?

In recent years, the construction industry has accelerated its shift from conventional 2D drawings and manual surveying-based construction management to 3D construction. There is a growing movement to capture entire sites as three-dimensional data and apply that data to design and inspection. The background includes momentum for construction DX driven by initiatives such as the Ministry of Land, Infrastructure, Transport and Tourism’s i-Construction, and the need to improve productivity to address severe labor shortages (the so-called “2024 problem”). Another major factor is recent technological progress that has brought 3D scanning (point cloud measurement)—previously usable only by specialist surveyors—into a stage where anyone can use it easily.

This article explains, in an easy-to-understand way, what “point cloud scanning” is, its principles, and its benefits—the key to 3D construction. Using the latest tool LRTK as an example, which enables high-precision point cloud measurement with a smartphone, we will look concretely at how sites will change. Let’s explore how traditional construction management is being updated and how an era is approaching in which anyone can use precise 3D data.

What Is Point Cloud Scanning? (Principles and Benefits)

Point cloud scanning is a measurement method that records an object in three-dimensional space as countless measured points and represents shape by that collection (point cloud data). Each point includes XYZ coordinate values indicating position (and, if photos are used, color information), and the higher the point density, the more precisely the real object can be reproduced like a photograph. For example, converting terrain or structures into a point cloud yields digital data that resembles a 3D photograph of the entire site. The acquired point cloud data can be viewed from arbitrary viewpoints on a computer, and used for dimension measurement and comparison analysis with design data. It is truly a technology for creating a “digital twin” of the site.

There are various methods for acquiring point cloud data. Representative examples include fixed 3D laser scanners for high-density measurement, aerial photogrammetry using drones, and convenient scans using the latest smartphone-built-in LiDAR. Each has pros and cons, but the shared benefit is that they can measure a wide area accurately in a short time. Unlike traditional ground surveying that measures points one by one, it has been reported that terrain surveying that once took a person half a day can be converted into a point cloud of the entire site in tens of minutes using a drone. Also, by using laser or aerial photography, existing conditions can be safely captured in places where people cannot enter. For these reasons, point cloud scanning is expected to streamline and enhance a wide range of operations from surveying to construction management and maintenance.

In practice, point cloud data is increasingly used for as-built control (post-construction shape inspection) and construction records. Inspections that once measured only parts of a finished structure can, with point clouds, check the entire structure to the millimeter. Small height differences and surface irregularities become instantly apparent in 3D, dramatically improving the accuracy of quality confirmation. Point clouds can be stored as detailed digital records of the finished shape, allowing accurate as-built drawings to be created from this data even if original drawings are unavailable. The Ministry of Land, Infrastructure, Transport and Tourism also recommends using point clouds for as-built control, and the data serve as valuable materials for future maintenance.

Point Cloud Scanning Anyone Can Do with LRTK

LRTK is a modern positioning and point cloud measurement tool composed of a small RTK-GNSS receiver that can be attached to a smartphone and a dedicated app. When attached to a phone, real-time satellite positioning enables the smartphone to obtain centimeter-level high-precision position information. If you scan the surroundings simultaneously with the phone’s camera or LiDAR sensor, anyone can acquire 3D point cloud data with absolute coordinates on the spot. It is truly a revolutionary solution that turns a smartphone into a high-precision 3D scanner.

Usage is also very simple. For example, you attach the LRTK receiver to your smartphone, launch the dedicated app, and start positioning. After receiving satellite correction information in tens of seconds and achieving high-precision positioning, walk around the site with the phone and scan with the camera/LiDAR. Because the point cloud is displayed in real time on the phone screen, you can proceed while confirming that nothing is missed. The acquired point cloud is automatically tagged with high-precision positional coordinates so you can use the data immediately after scanning. This is the strength of LRTK: precise 3D measurement can be performed by anyone with just these steps, without special equipment or advanced surveying skills.

With LRTK’s emergence, the barrier to 3D scanning has dropped dramatically. Compared with traditional laser scanners and drone measurements, the main advantages are:

• Ease and versatility: Unlike heavy fixed scanners, a smartphone + LRTK is portable and quick to set up. You can flexibly scan in confined indoor spaces, tunnels, underground pits, or even at night, without being limited by location or time. Unlike drones, there is no need for flight permits or weather constraints, so you can start measuring as soon as you decide. Anyone from newcomers to veterans can intuitively operate it alone, making it usable by everyone on site.

• Low cost: Introducing high-performance 3D laser scanners or surveying drones required large investment, but smartphone + LRTK can be started relatively inexpensively. Because you can use existing smartphones, initial investment is greatly reduced, making it easier for small and medium construction companies to adopt the latest point cloud technology. Renting or subscribing also allows use only for required periods, so benefits can be enjoyed regardless of project scale.

• High accuracy anywhere: LRTK supports Japan’s high-precision satellite positioning service “Michibiki” CLAS, enabling direct reception of correction information from satellites even at sites without internet connectivity such as mountainous areas or offshore, maintaining centimeter-class accuracy. It provides cm-level positioning (centimeter-level; half-inch accuracy) anywhere, making precise 3D scans possible “by anyone, anywhere, anytime.” It is compatible with ICT construction and i-Construction initiatives promoted by the Ministry of Land, Infrastructure, Transport and Tourism, and is attracting attention as a technological innovation that accelerates DX in the construction industry.

Immediately Visualize Volume, Area, and Cross-Sections from Point Cloud Data

Another major advantage is that, after acquiring point cloud data, required quantities and shapes can be visualized immediately. Using dedicated software or cloud tools, you can instantly measure arbitrary distances, areas, and volumes from the point cloud. For example, scan a pile of excavated soil with LRTK and calculate its volume on the spot to immediately determine the number of dump trucks needed. What used to require on-site surveying and returning to the office to calculate earthwork—taking half a day or more—can now be completed with a few minutes of scanning. Immediate understanding of daily progress (earth volume) dramatically speeds decision-making for equipment operation plans and truck arrangements.

It’s also easy to create cross-sections from point cloud data to verify shapes. You can extract any vertical section on the point cloud and measure heights and thicknesses in that section. For example, you can check cross-sections at multiple points on roads or developed land to visually confirm whether the slope matches the design. Software automates the once laborious drawing process, so you can confirm on-site with a tablet in hand. On LRTK’s cloud service, point clouds can be displayed in a browser and distance, area, and volume can be measured with one click, so basic quantity calculations and cross-section checks are possible without specialized software. Field personnel can measure and decide immediately as needed, greatly improving operational efficiency.

Instantly Check Deviations from Design by Comparing with Design Data

Acquired point cloud data can be overlaid and compared with the 3D models or drawing data used in design. This allows immediate verification on-site of whether the shape and dimensions of the finished work match the design. Traditional as-built control typically involved measuring a few points after completion and comparing them with drawings, but point clouds allow planar checks of the entire structure with no missed areas. Small height shortages or positional deviations are apparent in 3D, and if deviations exceed tolerances you can decide corrective measures on the spot. For example, in riverbank protection work, after concrete casting, the as-built point cloud acquired with LRTK was overlaid with the design 3D model to comprehensively verify finishing deviations. Inspections that previously measured only key points after completion now enable instant understanding of where and by how much deviations exist on the point cloud, eliminating gaps in quality control. Detecting errors early and reworking them prevents rework in later processes.

LRTK’s cloud also includes a feature that color-codes differences between point cloud and design data as a heat map. Because height differences are intuitively shown in warm and cool colors, even less experienced personnel can quickly recognize problem areas. You can confirm error quantities numerically for each part or visualize deviation by overlaying the design line and point cloud in a cross-section. Inspection results can be output as reports with charts and tables, streamlining the creation of as-built reports. The acquired 3D as-built data can be stored as electronic deliverables and serve as valuable assets for future maintenance and records.

Use AR to Overlay Design on Site and Support Construction

With the high-precision positioning provided by LRTK, site support using AR (augmented reality) functionality is also possible. By overlaying design 3D models or drawing lines onto the live camera view of a smartphone or tablet, you can project digital data onto the actual scene. For example, displaying the planned structure model in AR on the ground before construction helps intuitively share the completed image that is hard to grasp from drawings alone. It smooths explanations to clients and communication among site staff, making spatial consensus like “this will be here” easy. During construction, overlaying the design model on the real scene to confirm finishing positions allows immediate on-site checks of placement and height. This eliminates the need to rely on intuition and enables anyone to accurately detect installation errors, reducing rework and improving quality.

LRTK’s AR has many other applications. For example, in buried pipe construction, scanning the piping with LRTK before backfilling allows you to confirm the pipe’s position and depth in AR after burial just by pointing your smartphone. This improves safety for work near hazardous gas pipes or cables by identifying unseen buried objects in advance. You can also display design reference points and lines in AR and use them for layout work (marking). Processes that previously required surveyors to set up batter boards can now be done by following on-screen guides and marking points, allowing individuals with limited surveying experience to achieve accurate positioning. On site, tablets or AR glasses can display point cloud data and design models overlaid on the real scene to indicate corrective areas while visually confirming as-built conditions. As digital and physical fuse through AR, construction management and communication are undergoing major changes.

Changes at Sites from Implementation: Efficiency, Quality, Communication

Introducing 3D point cloud scanning (LRTK) has brought major changes to site operations:

• Improved operational efficiency: Time and effort for surveying and inspection are greatly reduced. A single scan can record an entire large site, so tasks that previously took multiple days can often be completed in hours or minutes. For example, as mentioned above, earth volume calculations that took half a day were shortened to minutes. The Ministry of Land, Infrastructure, Transport and Tourism’s survey reported that using ICT construction reduced average earthwork time by about 30%, clearly showing the productivity benefits of point cloud technology. Because measurements can be taken without contact, surveyors are less often required to enter high or hazardous locations, improving safety. The ability to measure with fewer people and in less time makes operation feasible even on labor-short sites.

• Advanced quality control: Because point clouds can measure the site exhaustively, inspection precision for construction quality improves dramatically. Millimeter-level unevenness and dimensional differences that were previously overlooked by manual methods can be detected in 3D, ensuring nonconforming areas are corrected. By increasing the number of inspection points, variability and omissions in quality are eliminated, raising client trust. Saving inspection results as point cloud data also aids future repairs and verification, enabling long-term quality assurance. Reduced rework shortens schedules and cuts costs, achieving both quality and productivity.

• Smoother communication: 3D data is visually easy to understand and dramatically streamlines information sharing among stakeholders. Sharing point clouds and models on the cloud makes it easy for head office or clients to remotely review the site in three dimensions. As-built conditions that were difficult to convey with verbal explanations or 2D drawings become immediately clear with a 3D model, shortening meetings and reporting times. Explaining with models on-site using AR allows even non-experts to understand intuitively, significantly reducing time to reach agreement. Sharing data across site and office, client and contractor, fosters project unity and smoother communication.

Conclusion: The Future of 3D Construction Opened by LRTK and Point Cloud Scanning

With the spread of point cloud scanning and ICT technologies, 3D construction is finally becoming a reality. As seen in this article, tools like LRTK enable anyone to digitize entire sites and immediately apply that data to construction. This is not merely an evolution of measurement methods but an impactful transformation of construction management itself. Areas once dependent on experience and intuition are replaced by data-driven objective decisions, enabling both efficiency and quality. Visualizing sites with 3D scans and AR dramatically increases construction transparency and productivity, powerfully advancing DX in the construction industry.

Going forward, the use of point cloud data and digital twins will increasingly become standard. High-precision 3D construction will become indispensable not only for large-scale projects but also for small and medium sites. Adapting early to these trends will create significant advantages in operational efficiency and competitiveness. Fortunately, solutions like LRTK make it possible to adopt state-of-the-art 3D surveying without large investments or specialized knowledge. Consider bringing this 3D construction revolution to your sites and stepping into next-generation construction management.

Bonus: Simple Surveying with LRTK

A final bonus note: LRTK is not only for advanced 3D point cloud measurement but is also very useful as an everyday simple surveying tool. With just one smartphone, you can perform tasks that previously required transit or level instruments, such as establishing reference points, checking elevation differences, and measuring distances. For example, if you want to “know the coordinates of this point,” “mark a specified location on the drawing,” or “quickly measure the distance between two points,” LRTK lets site staff solve these issues without waiting for a specialist surveyor. Even beginners can obtain centimeter accuracy (half-inch accuracy) coordinates by following the app prompts and tapping buttons, dramatically lowering the barrier to surveying. When sudden surveying needs arise, all you need is a smartphone to respond, speeding up the site and improving flexibility.

In this way, LRTK reliably transforms a smartphone into an all-purpose surveying instrument. From high-precision GNSS point observations to detailed point cloud scanning and AR-assisted construction support, it meets a wide range of needs with a single device. You can start with simple surveying and, as you become familiar, take on point cloud scanning—allowing gradual adoption of the latest technology according to your company’s operations. Try LRTK to experience easy, smart surveying and construction management.