CONEXPO-CON/AGG Accelerates Construction DX: Spotlight on LRTK's High-Precision AR Solution

Table of Contents

• Acceleration of construction DX seen at CONEXPO-CON/AGG

• What is LRTK's high-precision AR solution?

• Intuitive on-site construction with AR navigation

• Solo-guided stake placement

• As-built verification and point cloud overlay with AR

• Sharing site data via the cloud

• Construction DX solves on-site issues

• Summary

• FAQ (Frequently Asked Questions)

Acceleration of construction DX seen at CONEXPO-CON/AGG

In recent years, the construction industry has seen a rapid spread of digital transformation (DX), and this trend has reached construction sites as well. At the international large-scale construction exhibition CONEXPO-CON/AGG, many cutting-edge technologies that dramatically increase on-site productivity were showcased, drawing major attention to the acceleration of construction DX. ICT construction machinery, drone surveying, autonomous construction equipment, and 3D as-built management—solutions related to construction DX—were on full display. These areas have been increasingly of interest in the industry, partly driven by the Ministry of Land, Infrastructure, Transport and Tourism’s promotion of “i-Construction” and “3D as-built management.” At one of the world’s largest construction shows, attendees paid close attention to the digital technologies that contribute to efficiency, labor savings, and improved safety.

Among these, the combination of high-precision GNSS positioning and AR (augmented reality) construction support technology attracted particular attention. For example, LRTK’s high-precision AR solution—which can achieve everything from centimeter-level positioning to 3D scanning and AR navigation using just a smartphone—drew interest on the international stage as an innovative approach directly linked to improved site productivity.

What is LRTK's high-precision AR solution?

LRTK is a solution consisting of a pocket-sized high-precision GNSS device that attaches to a smartphone and a dedicated app. True to its slogan, “Turn your smartphone into a versatile centimeter-grade surveying instrument!”, simply attach the palm-sized device to your phone and launch the app, and anyone can easily perform surveying and as-built management tasks that previously required specialized equipment and skilled technicians. The LRTK device supports real-time GNSS positioning augmentation services (RTK), and in Japan it also supports the CLAS signal provided by the Quasi-Zenith Satellite System (Michibiki). As a result, it can deliver stable high-precision positioning with an error of only a few centimeters (a few in) even in mountainous areas outside of communication coverage. Errors that used to be on the order of several meters with a smartphone’s GPS are dramatically reduced with LRTK, allowing users to always know their position to the centimeter level (cm level).

The LRTK app integrates a variety of useful on-site functions that leverage highly accurate position information. The main functions are as follows.

• Point surveying: Measure any desired point with a single tap and instantly record accurate coordinate values.

• Point cloud scanning: Simply walk around while shooting with the smartphone’s built-in LiDAR or camera to generate detailed 3D point cloud data.

• AR display: Overlay lines and shapes from drawings or design models onto the real scene on the smartphone screen to intuitively confirm positions and dimensions on site.

• Automatic generation of as-built record books (photo logs): When you take a photo, the shooting location (latitude, longitude, height) and the camera orientation are recorded, and a photo log is automatically created in the cloud.

These functions significantly reduce tedious manual work and recording mistakes. In the following sections, we will look concretely at LRTK’s representative functions and the benefits they bring to on-site construction.

Intuitive on-site construction with AR navigation

One of LRTK’s innovative features is AR navigation support for construction. By displaying the real landscape on the smartphone screen and overlaying CG representations of structures’ positions and reference lines based on design drawings, the system intuitively navigates workers to the designated locations. For example, if an underground piping route is displayed on the floor with AR, you can understand the position of subsurface utilities as if you were seeing through the ground. You can also project a virtual model of the foundation shape and position to be installed onto the ground, making it immediately obvious “where the structure should be built.”

Notable is the accuracy and stability of that AR display. With conventional simple AR on a smartphone alone, the overlay can gradually drift as you move. However, LRTK keeps the device’s position and orientation continuously and highly accurately corrected using centimeter-class GNSS (cm-class GNSS) and high-performance inertial sensors, so virtual objects remain precisely fixed in the real world even when walking around. In demos at the exhibition, staff held smartphones and moved around while the virtual piping lines and foundation outlines displayed under the floor stayed perfectly aligned with real positions, prompting attendees to exclaim, “It really doesn’t drift!” and “This is ready to be used on-site.”

By projecting drawing information directly into the real world, AR navigation demonstrates great power in construction DX. Since you can follow on-screen guides instead of relying on paper drawings and manual marking, even inexperienced staff can intuitively grasp the correct positions and shapes. As a result, communication loss and construction mistakes are reduced, preventing rework. On construction sites, “misreading drawings” or “misunderstanding positions” often cause rework, but AR enables accurate visualization from the start, reducing such waste.

Solo-guided stake placement

Traditionally, layout tasks for building foundations and structures (so-called stake placement) required surveyors working in pairs operating a total station, transferring dimensions from drawings to the site to mark stakes. LRTK shows the potential to handle this stake placement guidance with just a smartphone. Using the LRTK app’s “coordinate navigation” feature, the phone guides you to preset target coordinates with arrows and distance, so the worker can move toward the target as if following a car navigation system and identify the target point.

Specifically, the smartphone screen displays real-time guidance such as “North by ○.○ m (○.○ ft), East by ○.○ m (○.○ ft),” making it immediately clear how far off your current position is from the target. When the distance display approaches zero and the phone issues a notification, that is the precise point to drive the stake. In the exhibition demo, staff followed this coordinate navigation on foot, and the mark placed at the instructed stop point matched exactly. The audience applauded, amazed at how “anyone with a smartphone in hand can now do layout.”

This solo stake placement guidance greatly contributes to on-site productivity and labor savings. In sites short of skilled surveyors or at small-scale construction sites, LRTK enables high-precision layout without significant manpower. It also eliminates the need for workers to mutually verify measurements for layout, reducing surveying errors. This is truly a new workflow on site brought by construction DX.

As-built verification and point cloud overlay with AR

As-built management, which verifies whether structures and terrain are completed according to design after construction, is important in construction. LRTK streamlines this as-built verification process. By walking around and scanning the finished subject with a smartphone’s LiDAR scanner or camera, you can obtain the site’s 3D point cloud data in just a few minutes. The point clouds acquired with LRTK are already aligned to the survey coordinate system and have absolute coordinates, so you can compare them with the design model immediately after acquisition without any post-alignment adjustments.

For example, in an embankment project, you can overlay the scanned as-built point cloud and the design model on the LRTK cloud and instantly compute numerical differences. Information such as whether the embankment is higher or lower than the design and whether the earthwork volume is deficient or excessive is immediately visualized as a heat map (color-coded map). In the exhibition demo, point clouds captured on site were uploaded to the cloud and a difference heat map against the design data was generated in a short time. Remarkably, this heat map result was also transferred back to the smartphone for on-site AR display and verification. In other words, you can visually confirm through the phone whether the exact spot you are standing on is “◯ cm (◯ in) higher” or “lower” than the design, displayed in color.

This workflow dramatically shortens the time required for as-built verification. Normally, after construction, a surveying team would measure the site, take data back to the office, and compare as-built results in CAD or spreadsheets. With LRTK, you can “scan on site → instantly check differences → make on-the-spot adjustments.” This reduces situations where rework is demanded later due to as-built errors. The combination of point cloud data and AR is a powerful tool to accelerate the field introduction of the Ministry of Land, Infrastructure, Transport and Tourism’s promoted “3D as-built management.”

Sharing site data via the cloud

LRTK also has robust mechanisms for data sharing via the cloud. Coordinates of surveyed points and photos and point cloud data captured can be uploaded from the smartphone directly to the LRTK-dedicated cloud. Uploaded data can be viewed and used immediately from office PCs or stakeholders’ devices. There is no need to install dedicated software; by issuing a shareable web URL, you can easily share 3D data with subcontractors or clients who do not hold a license. For example, if a site supervisor uploads point clouds obtained by surveying to the cloud, designers and general contractors can review that data from the office and promptly discuss whether additional embankment is required.

Moreover, the LRTK cloud is not just a storage repository: it includes a viewer function that can render point clouds and 3D design models in 3D in the browser and measure distances, areas, and volumes. This makes it smooth to perform detailed analysis or drafting in the office based on data captured on site. Of course, cloud data is managed securely, and you can set access permissions or issue password-protected share links as needed. Seamless site-office data linkage streamlines administrative work such as report generation and enables real-time sharing of site conditions for faster decision-making.

Construction DX solves on-site issues

As seen so far, LRTK’s high-precision AR solution, which attracted attention at CONEXPO-CON/AGG, helps solve a variety of on-site challenges. First, in response to labor shortages and the aging workforce, its ease of use without requiring specialized operators is a major solution. AR navigation allows younger staff to identify construction positions without confusion, and stake placement guidance enables solo work, realizing construction that does not rely on veteran know-how. This makes it easier to secure consistent quality even on sites with limited personnel.

Second, there are significant effects on shortening schedules and reducing costs. The speeding up of point surveying and point cloud scanning and the immediate as-built verification mean tasks that used to take days can be completed on site. For example, if earthwork volume calculations can be measured and verified the same day rather than postponed, construction plans can be revised quickly and resources optimally allocated. Early detection of errors and mistakes reduces rework and material waste, leading to overall cost reduction.

Furthermore, DX is powerful in terms of safety management and information sharing. Visualizing the positions of buried utilities with AR reduces the risk of accidentally damaging pipes, and immediately sharing as-built data in the cloud ensures all stakeholders work with a common set of up-to-date information. These measures help prevent human error and enable smoother consensus-building. The true value of construction DX lies in reducing on-site waste, inefficiency, and unevenness while improving quality and safety and raising productivity.

Summary

The wave of construction DX that will shape the industry’s future is gaining momentum at domestic and international exhibitions. The reason LRTK’s high-precision AR solution drew attention at international events such as CONEXPO-CON/AGG is that its practicality and innovativeness match on-site needs. LRTK, which handles everything from surveying to construction support and as-built management with only a smartphone and a small device, is truly a “versatile tool” for the DX era. From now on, construction sites will require workers to use digital technologies to work efficiently and accurately rather than relying on paper drawings and intuition. LRTK’s demonstrated potential as a solution to help realize that future is significant.

By utilizing LRTK for simplified surveying, we can expect high-precision on-site measurement and recording to become commonplace regardless of experience or specialized knowledge. To avoid being left behind by the construction DX wave, it is important to actively adopt such cutting-edge technologies. As the global construction industry undergoes major changes driven by DX, Japan must also promote on-site DX to achieve a productivity revolution. It would not be an exaggeration to say that the adoption of leading-edge technologies will determine future competitiveness.

FAQ (Frequently Asked Questions)

Q. What is LRTK? I heard it was in the spotlight at CONEXPO-CON/AGG. A. LRTK is a high-precision positioning and AR solution composed of a small device that attaches to a smartphone and a dedicated app. It was showcased at international exhibitions such as CONEXPO-CON/AGG in 2026 and attracted attention as an innovative tool capable of on-site surveying, 3D scanning, and AR-based construction support.

Q. Can a smartphone really achieve centimeter-level positioning? A. Yes. Using the LRTK device and app makes it possible. By integrating signals from multiple GNSS satellites and using correction technology called RTK, it dramatically improves the accuracy of a smartphone’s GPS. In Japan, LRTK also supports the Michibiki CLAS augmentation signal, allowing it to maintain stable centimeter-level accuracy (cm-level) even in areas with poor communication.

Q. In what situations is AR-based construction support useful? A. AR construction support is useful in many situations such as stake placement, layout marking, confirming buried pipe locations, and checking finished shapes. For example, displaying drawing lines on the ground with AR allows inexperienced workers to install equipment in the correct positions. Also, sharing the completed image on site helps align stakeholders’ expectations before and after construction.

Q. How are captured point cloud and surveying data shared? A. Data captured with LRTK can be easily shared via the cloud. Upload from the smartphone to the LRTK cloud, and the data can be viewed and used via the internet by the office or other parties. You can overlay point clouds with design models in the dedicated viewer or share via URL so recipients can view the data without special software.

Q. Is installation or operation difficult? Can it be used without specialized knowledge? A. Operation is very simple and can be used without specialized training. Attach the LRTK device to your smartphone and launch the app; then follow on-screen instructions to perform surveying and acquire point clouds. The intuitive UI guides the user, so anyone comfortable with basic smartphone operations can use it immediately. There’s no need for cumbersome setup like mounting a tripod and adjusting equipment, so measurements can start on site right away. Because there is no need to allocate time for device handling training, it is easy to introduce even at small sites or for those who do surveying part-time.

Q. What are the benefits of promoting construction DX? A. Promoting construction DX brings many benefits such as addressing labor shortages, improving operational efficiency, enhancing quality, and strengthening safety management. By using digital technology, fewer people can complete accurate work in less time, reducing mistakes and rework. Also, direct data linkage between site and office smooths communication, enabling everyone to proceed with the project while sharing the latest information. This ultimately leads to cost reduction and strengthened competitiveness.