Construction & Surveying Productivity Improvement Expo Demonstration Report: Experiencing the Power of LRTK's AR Construction Support × High-Precision Positioning

Introduction

The "Construction & Surveying Productivity Improvement Expo (CSPI-EXPO)," an exhibition that brings together the latest technologies in the construction and surveying industries, is one of Japan's largest events, attracting many professionals each year. This year it was held again at Makuhari Messe, where numerous booths and attendees filled the venue with energy. At the 6th edition (held in 2024), 455 companies and 2,760 booths exhibited, and about 47,000 industry professionals visited over three days. The scale alone shows how much attention this expo receives.

At this exhibition, cutting-edge technologies that contribute to productivity improvements in the industry gather in one place. Particularly notable categories include ICT construction related to construction DX and i-Construction, smart construction machinery such as drone surveying and automated heavy equipment, devices utilizing high-precision positioning, and technologies that streamline on-site work such as AR (augmented reality) and 3D data-based construction records. Against the backdrop of initiatives promoted by the Ministry of Land, Infrastructure, Transport and Tourism—such as "3D as-built management"—and the on-site adoption of digital technologies, interest in these technologies has been rising year by year.

Among these technologies, one of the most eye-catching at this year's expo was the construction support solution combining AR and high-precision GNSS positioning. In this article, I visited the LRTK booth, where demonstrations were held, and report on my hands-on experience with their AR construction support × high-precision positioning capabilities.

Overall Impression of the LRTK Booth

Even within the vast Makuhari Messe venue, Refixia Co., Ltd.'s LRTK booth stood out as particularly busy. Many attendees stopped at the large slogan proclaiming, "Turn your smartphone into a cm-class all-purpose surveying instrument!" and a crowd remained around the booth throughout the event. The concept—that full-fledged surveying and construction support can be performed with a small device attached to a smartphone—drew interest from a wide range of people, from veterans with extensive field experience to young engineers, which was impressive.

The booth was divided into a demonstration area, product introduction panels, and a hands-on corner. In the central demo area, staff operated the LRTK device attached to a smartphone and mirrored the phone screen onto a large display for the demo. Panels around the area introduced LRTK functions and case studies, making it easy to imagine concrete use scenarios. There was also a hands-on corner where interested visitors could actually pick up the device and try it themselves, and attendees could be seen confirming the feel of the operation firsthand.

Visitors seemed particularly interested in two main points: one was "Can you really do surveying with a smartphone?" and the other was "How accurate is the AR display?" Staff carefully explained during the demo that "simply attaching the LRTK device to a smartphone and launching the dedicated app enables immediate high-precision positioning," and that "correction information uses Japan's Quasi-Zenith Satellite Michibiki (CLAS), allowing cm-class positioning even in mountainous areas without cellular coverage." For attendees who assumed smartphone GPS had meter-level errors, the notion of routine centimeter-level positioning was surprising, and many listened intently.

Summarizing the features exhibited and demonstrated at the booth, LRTK—described as a "pocket-sized all-purpose surveying instrument"—offers a variety of functions unique to that concept:

• Centimeter-level high-precision positioning: With proprietary RTK-GNSS technology, it can acquire current position with about 1 cm accuracy (supports Michibiki's CLAS signal, maintaining accuracy even outside of communication coverage).

• Point cloud measurement via 3D scanning: Using built-in LiDAR scanners or cameras in smartphones and tablets, the system acquires on-site objects as 3D point cloud data, allowing immediate volume calculations and shape checks on the spot.

• AR-based construction navigation: Structures and reference lines from design drawings or BIM models can be overlaid onto the real-world view as AR, enabling precise alignment on site. This supports layout marking and drawing interpretation, realizing intuitive construction navigation.

• Cloud integration and data sharing: Measured points and photos (including capture location and orientation) are uploaded to the cloud immediately and can be shared and reviewed on office PCs. Compatibility with CAD data and BIM integration is smooth, improving information sharing between site and office.

• Ease of use and cost savings: The compact, lightweight device with built-in battery is easy for anyone to handle during site work. It is significantly less expensive than conventional dedicated surveying equipment and requires no extensive training, making it suitable for small sites and multi-site deployment.

With these functions, LRTK was presented as a "universal surveying instrument," and the booth offered demos that made these advantages immediately understandable. Next, let’s take a closer look at the AR construction support demonstration, which particularly drew visitors’ attention.

AR Construction Support Demonstration

The AR feature-based construction support demo drew the most attention at the LRTK booth. At scheduled times, staff would raise the smartphone toward the audience and announce, "We will now show AR construction navigation." The display showed the floor surface in front of the booth as captured by the smartphone camera.

In the demo, pre-loaded design data was read into the LRTK app on the phone, and the design structures and markers were overlaid on the camera image. For example, although there was nothing on the floor, the smartphone screen vividly displayed a CG line representing an underground pipe route, as if peering beneath the floor. In another scene, the position and width of a virtual foundation drawn on the ground were shown in AR, and the outline of a planned structure appeared to float in the real space. In both cases, virtual information lined up precisely with the real objects thanks to centimeter-level positioning accuracy, prompting audible gasps from the audience at the high level of precision.

Even when staff walked around holding the smartphone, the AR display hardly ever shifted. Typically, simple smartphone AR can drift slightly as you move, but LRTK continuously corrects position and orientation with GNSS and inertial sensors, so virtual objects remain firmly fixed in the real world while in motion. Attendees murmured comments like, "It really doesn't shift," and "This could be used on site immediately," watching the demo screens intently.

What visitors experienced in this AR construction support demo was the clarity of displaying design information directly in space without relying on drawings or survey stakes. For example, tasks that traditionally involved marking positions while referring to paper drawings or survey plans can now be done simply by following a line displayed on the screen. Even staff with limited field experience can intuitively grasp the correct positions and shapes, reducing communication loss and preventing construction errors. One young engineer watching the demo laughed that "you can align positions like a game," while still expressing admiration for its usefulness.

Smartphone Surveying Demo

Following the AR demo, a demonstration of surveying and measurement using a smartphone was presented. Staff recreated concrete tasks to show what LRTK’s other pillar—"high-precision smartphone surveying"—actually looks like.

First, they demonstrated a simple point surveying workflow. A staff member stood at an arbitrary point set up inside the booth, held the smartphone, and tapped the app's "Measure here" button. The coordinates of that point were instantly obtained and recorded. Because positioning accuracy is high, repeated measurements at the same point returned almost identical values each time, confirming stable measurement. Where conventional work might require time-consuming observations with a total station or dedicated GNSS receiver, LRTK’s ease—complete point measurement in seconds with just a smartphone—prompted surprised reactions from the audience. Many nodded, saying, "You could measure this between jobs on site."

Next, a 3D point cloud acquisition demo using the smartphone's built-in LiDAR sensor was conducted. Staff activated the LiDAR sensor and walked around a model object placed in the booth to scan it. A point cloud was generated in real time on the screen, and the object's shape gradually appeared as a collection of points in three dimensions. The scan completed in just 1–2 minutes, prompting comments like, "You can make a 3D model this easily?" Staff then overlaid the acquired point cloud with the site design's 3D model in the cloud and quickly created an as-built heat map (a color-coded map showing deviations from the design). Because the point cloud itself contains cm-accurate positional information, such comparisons can be made without complicated alignment work. This functionality enables, for example, immediate on-site confirmation of embankment or excavation as-built conditions and the ability to make corrections on the spot if discrepancies are found. The generated heat map can be transferred back to the smartphone and even overlaid in AR onto the real world. Many attendees felt they had glimpsed the cutting edge of digital construction management in this workflow.

The coordinate navigation (so-called stakeout navigation) demo also attracted attention. Staff entered preconfigured target point coordinates (virtual survey points) into the app and started navigation mode. The smartphone displayed directional and distance guidance such as "0.12 m north, 0.07 m east," and the staff followed the instructions and walked slowly. As the distance readout approached zero, the phone signaled arrival at the target point with sound and on-screen notification. Looking at the staff member's feet, the marker placed as a reference was almost exactly at the indicated position, confirming that the smartphone had guided them to the target point. The onlookers applauded at this demonstration. Compared with traditional stakeout—where positions are derived by chasing dimensions on paper drawings—this offers the ease of reaching stakeout positions almost like using a car navigation system. The scene suggested that stakeout, which traditionally required a two-person surveying team using a total station, might be achievable by one person with a single smartphone.

Through this series of smartphone surveying demos, visitors experienced LRTK's versatility and practicality firsthand. From single-point surveying to 3D scanning, matching against design data, and stakeout navigation—tasks that previously required separate devices and specialized work—could be completed with just a smartphone. The demonstration strongly underscored the potential of on-site DX.

Conversations at the Booth and User Feedback: What Makes Users Decide to Adopt It

After the demos, lively Q&A and exchanges took place between staff and visitors at the booth. From these conversations, certain points emerged as decisive factors influencing consideration of solutions like LRTK. Below are some of the voices heard at the venue and the key factors they highlighted.

A site manager from a mid-sized construction company commented, "Recent DX tools seemed to require specialized knowledge, so we hesitated to adopt them, but this looks simple enough that anyone could use it." The smartphone-app-centered operation and immediately comprehensible interface appear to make it accessible even to those unfamiliar with digital devices. A technician from a surveying company said, "I was worried about accuracy, but after seeing the demo, I realized the precision is sufficient for practical work. We could integrate this into daily surveying tasks," indicating that their initial concerns about new technology were alleviated.

On questions about price, staff explained that "compared to conventional high-precision equipment, the initial cost is much lower, so it makes economic sense even for smaller sites," which attendees listened to with nods. Even if it is difficult to equip every site with expensive dedicated instruments, affordable LRTK units could realistically be assigned to each team. A manager at a civil engineering company joked that "we could probably get budget approval for this right away," showing that cost-effectiveness is a major appeal.

A young site supervisor also praised the AR function as "a trump card for reducing construction errors." He noted that if non-experts can display the finished image and design lines on site with AR, "misunderstandings that lead to rework would decrease, which should shorten overall schedules." Regarding LRTK’s cloud-sharing features, someone said, "It’s great that photos taken on site are uploaded with location data to the cloud. It eliminates the need to manually annotate and share on drawings," indicating appreciation for smoother information flow between site and office.

From the voices heard at the venue, the decisive factors for adopting LRTK-like solutions can be summarized as follows:

• Ease of use: The smartphone-centric system is intuitive and can be used by staff without specialized technical training.

• Multipurpose capability in one unit: From surveying (GNSS measurement) to 3D recording and construction support (stakeout guidance and as-built inspection), a single device covers a wide range of uses.

• Practical precision: Centimeter-level positioning and stable AR display provide quality sufficient for actual construction management and surveying deliverables.

• High cost performance: Initial investment is lower than existing surveying equipment, and it is efficient in terms of maintenance and personnel costs. Affordable mass deployment lowers the barrier to DX.

• Data integration and DX compatibility: Real-time cloud sharing and smooth CAD/BIM integration make it easy to incorporate into future digital construction workflows.

These points led many to say that LRTK "could become an ideal tool for advancing on-site DX." Experiencing user perspectives in person at the expo clarified the value LRTK can bring to sites. Visitors who had been skeptical about smartphone surveying before the demos left convinced of its usefulness and enthusiastically imagined post-adoption use cases.

Conclusion

Through the LRTK demonstrations at the Construction & Surveying Productivity Improvement Expo, I experienced firsthand the DX effects that AR × high-precision positioning can bring to worksites. Adding digital accuracy and visual clarity to tasks that once relied on paper drawings and seasoned intuition makes a future where anyone can perform tasks accurately and quickly feel within reach.

Smartphone-based solutions like LRTK are likely to become standard on worksites going forward. In an industry facing severe labor shortages due to demographic change, tools that require no special skills can be a key to standardizing skills and improving productivity. The ability to acquire and share on-site data in real time also directly supports faster decision-making and quality assurance in construction management. The concept of "surveying anyone can do, AR anyone can use" could strongly propel the next wave of on-site DX.

The LRTK demonstrations reported here concretely illustrated that future. Many attendees at the venue experienced the new value created by the fusion of AR and GNSS. If you haven't experienced it yet, please take this article as an opportunity to explore the potential of this smartphone surveying tool. As a key that can make on-site digital transformation more accessible, LRTK may soon prove invaluable at your worksites.

Going forward, smartphone positioning technologies like LRTK will continue to evolve and will increasingly contribute to on-site smartification and automation in collaboration with AI, robotic construction equipment, and IoT sensors. As a result, the very nature of surveying and construction management is likely to change dramatically. The cutting-edge solutions glimpsed at the Construction & Surveying Productivity Improvement Expo were a preview of such future worksites. As the industry as a whole steers toward DX, this exhibition continues to be a valuable opportunity to gather hints for the future. Actively adopting these technologies will surely be key to success on tomorrow’s construction sites.