Construction & Survey Productivity Improvement Expo Demonstration Report: Experiencing LRTK’s AR Construction Support × High-Precision Positioning

Introduction

The Construction & Survey Productivity Improvement Expo (CSPI-EXPO), an exhibition where the latest technologies in the construction and surveying industries gather, is one of the largest events of its kind in Japan and attracts many professionals each year. This year it was held again at Makuhari Messe, and the venue was filled with numerous booths and enthusiastic visitors. At the 6th edition (held in 2024), 455 companies exhibited across 2,760 booths, and about 47,000 industry professionals attended over three days. The scale alone shows how much attention this expo draws.

At this exhibition, advanced technologies that contribute to industry productivity improvements are gathered in one place. Categories drawing particular attention 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 the Ministry of Land, Infrastructure, Transport and Tourism’s promotion of “3D as-built management” and the on-site adoption of digital technologies, interest in these technologies has been growing year by year.

Among these technologies, one of the most eye-catching at this year’s expo was construction support solutions that combine AR with high-precision GNSS positioning. In this article, I visited the booth for “LRTK,” which performed live demonstrations at the venue, 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, Reflexia Co., Ltd.’s LRTK booth stood out as particularly busy. Many visitors stopped at the large slogan proclaiming “Turn your smartphone into a centimeter-level (half-inch-level) all-purpose surveying instrument!”, and a crowd gathered around the booth throughout the event. The concept—that a small device attached to a smartphone can perform full-fledged surveying and construction support—drew interest from a wide range of attendees, from experienced veterans to young engineers, which was impressive.

The booth was divided into a demonstration space, product introduction panels, and a hands-on experience corner. In the central demo area, staff operated an LRTK device attached to a smartphone and mirrored the phone’s screen to a large display for demonstrations. Panels around the area introduced LRTK’s features and implementation examples, making it easy to imagine concrete use cases. There was also a hands-on corner where interested visitors could actually pick up and try the device, and many attendees were seen testing the feel of the product themselves.

Visitors’ interest seemed to focus mainly on two points: one, “Can surveying really be done with a smartphone?” and two, “How accurate is the AR display?” Staff explained carefully during demonstrations that “simply attaching the LRTK device to a smartphone and launching the dedicated app makes high-precision positioning immediately possible,” and that “correction information uses Japan’s Quasi-Zenith Satellite System Michibiki (CLAS), enabling centimeter-level (half-inch-level) positioning even in mountainous areas outside communication coverage.” For visitors who believed smartphone GPS typically has errors on the order of meters, the claim that positioning to within a few centimeters is routine came as a surprise, and they listened intently.

Summarizing the features of LRTK shown and demonstrated at the booth, the following versatile functions typical of a “pocket-size all-purpose surveying instrument” were highlighted:

• Centimeter-level high-precision positioning (half-inch accuracy): Using proprietary RTK-GNSS technology, it can obtain the current position with approximately 1 cm (0.4 in) positioning accuracy. It supports Michibiki’s CLAS signal, maintaining accuracy even outside communication coverage.

• Point cloud measurement via 3D scanning: By utilizing built-in LiDAR scanners or cameras in smartphones and tablets, site objects can be captured as 3D point cloud data, enabling on-site volume calculations and shape verification.

• AR-based construction navigation: Structures and reference lines from design drawings or BIM models can be overlaid onto the real-world scenery via AR, allowing precise alignment on site. This supports layout marking and intuitive construction navigation based on drawings.

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

• Ease of use and cost savings: The small, lightweight device includes a battery and can be handled by anyone during site work breaks. It is significantly less expensive than traditional dedicated surveying instruments and requires no specialized training, making it suitable for small sites and multi-site deployment.

These capabilities led LRTK to be called an “all-purpose surveying instrument,” and demos at the booth made these advantages immediately understandable. Next, let’s take a closer look at the live demo of the AR construction support, which particularly captured visitors’ attention.

AR Construction Support Demonstration

The AR-based construction support demonstration drew particular attention at the LRTK booth. At scheduled times, staff would raise a smartphone toward the audience and announce, “We will now show AR-based construction navigation.” The display showed the floor in front of the booth as seen through the phone’s camera.

In the demo, preloaded design data was read into the phone’s LRTK app, and design structures and markers were overlaid on the camera image. For example, even though nothing was visible on the floor, the phone screen displayed an underground buried pipe route as a vivid CG line, as if seeing through the floor. In another scene, the virtual location and width of a planned foundation were shown on the ground via AR, and the planned structure’s outline seemed to float in the real space. In both cases, virtual information was perfectly aligned with the real objects thanks to positioning accuracy on the order of several centimeters (several inches), prompting audible gasps from visitors impressed by the precision.

Even when staff walked around holding the smartphone, the AR overlays hardly shifted. With ordinary simple AR functions on a smartphone, displayed positions can drift gradually after some movement. But LRTK continuously corrects position and orientation with GNSS and inertial sensors, so virtual objects remained firmly fixed in the real environment during movement. Visitors commented things like, “It really doesn’t drift,” and “This looks ready for use on site,” watching the demo intently.

What visitors really appreciated in this AR construction support demo was the clarity of showing design information directly in space without relying on drawings or survey stakes. For instance, tasks that traditionally required marking positions while referring to paper drawings or survey plans can now be done by simply following lines displayed on the screen. Even staff with little site experience can intuitively grasp correct locations and shapes, reducing communication loss and preventing construction errors. A young engineer watching the demo laughed, saying, “You can align things like in a game,” while clearly impressed by its usefulness.

Smartphone Surveying Demonstration

Following the AR demo, a demonstration of surveying and measurement using a smartphone was held. Staff recreated concrete tasks to show what LRTK’s other pillar—high-precision smartphone surveying—can do.

First, they demonstrated a simple point measurement workflow. Staff stood at arbitrary points set in the booth, held the smartphone, and tapped the “Measure here” button in the app. The coordinates for that point were obtained and recorded instantly. Because the positioning accuracy is high, repeated measurements at the same point returned almost identical values, confirming stable measurement. Where time-consuming observations with total stations or dedicated GNSS receivers would traditionally be required, LRTK enables point measurement with a smartphone in a matter of seconds, prompting surprised reactions from visitors who noted, “You can measure this quickly during breaks on site.”

Next, a 3D point cloud acquisition demo using the smartphone’s LiDAR sensor was performed. Staff activated the smartphone’s LiDAR sensor and walked around a model object placed in the booth to scan it. Real-time point cloud data generated on the screen gradually rendered the object as a three-dimensional cluster of points. The scan completed in just about 1–2 minutes, and visitors expressed amazement, saying, “It’s so easy to turn this into 3D.” Staff then overlaid the acquired point cloud data with the site design’s 3D model in the cloud and quickly produced an as-built heat map (a color-coded diagram showing deviations from the design). Because the point cloud itself contains position information with cm-level accuracy (half-inch accuracy), such comparisons can be done without complicated alignment work. This functionality enables on-site checks of embankment or excavation as-built conditions in real time and, if discrepancies are found, immediate corrective work. The generated heat map can also be transferred to the smartphone and even overlaid in AR onto the real environment. Many visitors felt they had glimpsed the possibilities of modern digital construction management through this sequence.

The demonstration of coordinate navigation (so-called stake-out navigation) also drew interest. Staff entered coordinates for preconfigured target points (virtual survey locations) into the app and started navigation mode. The smartphone screen displayed guidance such as “North 0.12 m (0.39 ft), East 0.07 m (0.23 ft),” and the staff followed the instructions while walking slowly. As the distance display approached 0 m, the phone notified arrival at the target point with sound and screen indicators. Looking down, the marker placed as a reference was almost exactly at the target position, confirming the phone had guided the staff to the precise point. The watching visitors spontaneously applauded at this demonstration. Compared to traditional stake-out methods that calculate positions from dimensions on paper drawings, this “car-navigation-like” ease of arriving at stake positions impressed everyone. The scene suggested that tasks which used to require two surveyors with a total station might be possible with just a single smartphone.

Through this series of smartphone surveying demos, visitors felt the versatility and practicality of LRTK. From single-point surveying to 3D scanning, matching with design data, and stake-out navigation, processes that once required separate instruments and specialized tasks can now be completed with a single smartphone. The demonstrations strongly conveyed the potential of site DX.

Conversations at the Booth and User Feedback: What Drives Adoption

After the demos, active Q&A and exchanges took place between staff and visitors at the booth. From these conversations, several key factors emerged as decisive for adopting solutions like LRTK. Below are some of the voices and insights heard at the venue.

A site foreman from a mid-sized construction company said, “I hesitated to adopt recent DX tools because they seemed to require specialist knowledge, but this looks simple enough for anyone to use.” The smartphone-app-centered operation and intuitive interface make it easy for personnel unfamiliar with digital devices to adopt. A technician from a surveying company remarked, “I was worried about accuracy, but after seeing the demo I realized it’s accurate enough for practical use. We could incorporate this into our daily surveying tasks,” indicating that initial doubts about the technology were dispelled.

Regarding cost, staff explained that “compared to conventional high-precision equipment, the introduction cost is significantly lower, so it’s profitable even for small sites,” which listeners nodded along to. Even if it’s difficult to equip every site with expensive dedicated instruments, an affordable LRTK device could realistically be assigned per team. Indeed, a manager from a civil engineering firm joked, “We could probably get budget approval for this in our department right away,” showing that cost-performance is a major appeal.

A young site supervisor praised the AR function, saying, “This could be a trump card for reducing construction errors.” He suggested that even without veterans on site, displaying the completed image and design lines via AR could reduce rework due to misrecognition and thus shorten project schedules. Regarding LRTK’s cloud-sharing function, some said, “It’s great that photos taken on site upload to the cloud with position information; it saves the hassle of annotating drawings one by one,” appreciating smoother information sharing between site and office.

From these voices at the expo, the factors that stood out as decisive for adopting LRTK can be summarized as:

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

• Multi-purpose capability in one unit: Versatility to handle surveying (GNSS measurement), 3D recording, and construction support (stake-out guidance and as-built inspection) with a single device.

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

• High cost performance: Lower initial investment compared to existing surveying equipment and efficiency in maintenance and labor costs. Affordable widespread deployment lowers the barrier to DX.

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

These points led many to conclude that LRTK could be an ideal tool for advancing on-site DX. Experiencing user perspectives firsthand at the expo clarified the value LRTK brings to the field. Visitors who had been skeptical about smartphone surveying before the demonstrations nodded at its usefulness afterward and eagerly envisioned how they might use it on their sites.

Conclusion

Through the LRTK demonstrations at the Construction & Survey Productivity Improvement Expo, I was able to tangibly experience the DX effects that AR × high-precision positioning can bring to job sites. Adding digital accuracy and visual clarity to tasks that once relied on paper drawings and experienced intuition makes it possible for anyone to work accurately and quickly—reminding us that such a future is within reach.

Solutions that leverage smartphones like LRTK are likely to become standard on job sites. In a construction industry facing severe labor shortages due to demographic changes, tools that can be operated without special skills offer potent means to level skill differences and boost 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” may strongly drive the next phase of site DX.

The LRTK demo I reported on concretely demonstrated such a future. Many at the venue experienced the new value created by the fusion of AR and GNSS. If you haven’t experienced it yet, I hope this article encourages you to explore the potential of this smartphone surveying tool. LRTK may soon be a key player on your sites in making digital transformation tangible.

Going forward, smartphone positioning technologies like LRTK will continue to evolve and, in collaboration with AI, robotic construction machinery, and IoT sensors, will further contribute to site smartification and automation. As a result, the very nature of surveying and construction management is likely to change dramatically. The cutting-edge solutions glimpsed at the expo previewed that future worksite, and as the industry collectively steers toward DX, adopting such technologies proactively will be essential to unlocking the future of construction sites.