ICT Construction Definitive Edition: 3D Construction Anyone Can Do with LRTK

Introduction: The 3D Construction Revolution Spreading Across Job Sites

In recent years, ICT construction has been evolving dramatically in the construction industry. Site efficiency using “3D construction,” typified by surveying and as-built management, has attracted attention, but traditionally it required advanced expertise and expensive equipment. Now, however, an era has arrived in which each person on site can easily practice 3D construction with a smartphone in hand.

The driving force behind this is the groundbreaking solution "LRTK", used in combination with an iPhone. Even newcomers with no surveying experience can perform precise 3D point cloud scans, AR-based construction verification, and even navigation to stake-out positions using LRTK. Sites that once relied entirely on heavy surveying instruments and specialist staff are on the verge of a major transformation thanks to LRTK.

This article explains, in a story format, how LRTK changes 3D construction on construction sites. By contrasting traditional challenges with the solutions provided by LRTK and presenting concrete use cases, we unpack its power. Focusing on keywords such as point cloud scanning, AR construction verification, as-built management, coordinate navigation, and iPhone surveying, we explore the appeal of LRTK that anyone can use. Finally, we touch on the new possibilities brought by LRTK’s simple surveying functions and invite readers to consider the applications spreading across sites.

Challenges of Traditional 3D Construction: Dependence on Heavy Equipment and Specialized Skills

First, let’s organize the challenges of traditional 3D construction on construction sites before the arrival of LRTK. Central to promoting ICT construction are current 3D measurements and on-site as-built verification during construction, but these faced the following hurdles.

• Heavy equipment and complex operation: High-precision surveying required equipment such as total stations, GNSS receivers, and large 3D laser scanners. These must be mounted on tripods or poles, and because the instruments themselves are heavy, transporting and setting them up is cumbersome. Even setting them up on site took time and effort, and operating the equipment required experience.

• Dependence on specialists: 3D surveying and as-built management often relied on surveyors and specialist operators, and were not something general construction managers or workers could handle casually. For example, even performing a point cloud scan required a specialist to operate the equipment and to process and analyze the acquired data; it was not a situation where anyone on site could immediately use it.

• Time and cost burden: With traditional methods, planning the survey, executing it, and analyzing the results took significant time. For as-built management, even a single earthwork volume calculation required calling a surveying team, halting work to measure, and calculating volume from the bring-back data — a process that consumed personnel and days, creating a large cost burden. On smaller sites, it was sometimes necessary to forgo adequate 3D construction.

• Lack of real-time capability: Real-time situational awareness is important when operating heavy equipment, but traditional surveying involved a time lag until measurement results were available. Even if discrepancies with the design occurred during construction, they might not be discovered until periodic as-built surveys, risking rework.

As shown above, while traditional 3D construction offered significant benefits, it was not something anyone on site could immediately handle. The challenges of “equipment weight,” “specialization,” and “time and manpower” were substantial.

LRTK Paving the Way for 3D Construction Anyone Can Do

LRTK solves these traditional challenges at once and realizes “3D construction anyone can do.” LRTK consists of a compact RTK-GNSS receiver that mounts on an iPhone and a dedicated app, revolutionizing on-site positioning tasks with a device that fits in your pocket. No heavy equipment or large-scale setup is required; pick up your smartphone and you can perform high-precision surveying, point cloud measurement, and AR visualization on the spot.

In one phrase, LRTK’s characteristics are “lightweight & easy” yet “high-performance.” Specifically, it offers the following benefits.

• Pocket-sized high-precision device: The LRTK receiver weighs only a few hundred grams and attaches to an iPhone like a phone case. By using multi-frequency GPS satellite data with real-time corrections (RTK), the positioning error of a smartphone alone, which used to be about 5–10 m (16.4–32.8 ft), improves to approximately horizontal ±1–2 cm (±0.4–0.8 in) and vertical ±3 cm (±1.2 in). This allows you to obtain accuracy comparable to fixed-grade GNSS surveying equipment on site with ease.

• One-tap surveying and automatic logging: The dedicated app is designed to be easy for site beginners to use, without the need to worry about complicated settings. Hold up the iPhone where you want to measure and press a button to instantly record the latitude, longitude, and elevation of that point. Positioning data is automatically tagged with date/time and measurement quality, creating reliable records anyone can trust later. The era of writing numbers in a paper field notebook is over; your smartphone functions as an “electronic field notebook.”

• All-in-one functionality: LRTK is not limited to single-point coordinate measurement. In one app you can perform 3D point cloud scanning to measure entire terrains, use measurement data for distance/area/volume calculations, perform AR construction verification by overlaying design models on current conditions, and even navigate to stake-out positions based on design coordinates with coordinate navigation. All of this is completed with a single iPhone, eliminating the hassle of using separate devices or software. The ability to immediately measure and verify on the spot when inspiration strikes is unparalleled.

• Real-time sharing and cloud use: Point cloud data and coordinate information obtained with LRTK can be uploaded to the cloud and shared with stakeholders. Designers and supervisors in a remote office can instantly view the latest terrain data measured on site and check results with the push of a button. Because 3D data can be handled in a browser without dedicated software, the barrier to data utilization is lowered. Near-real-time collaboration between site and office enables earlier error detection and faster instructions.

Now, let’s look at specific use cases and effects for each of LRTK’s major functions.

Digitize the Entire Site with Point Cloud Scanning

Traditionally, recording 3D shapes such as slopes or foundation excavations required tens of minutes with a terrestrial laser scanner and post-processing to merge and align point clouds. LRTK makes the process of point cloud scanning astonishingly easy. By combining the iPhone’s built-in LiDAR sensor with LRTK’s high-precision positioning, you can obtain 3D point cloud data of surrounding terrain and structures simply by walking around the site.

For example, to determine earthfill quantities at an embankment site, a worker can obtain high-accuracy point cloud data by walking around the embankment for about one minute while holding an iPhone. Because the acquired point cloud is georeferenced with global coordinates (latitude, longitude, and elevation), it can be used in alignment with maps and design data without special registration work. While conventional smartphone LiDAR could produce distortions due to drift during scanning, LRTK corrects the device’s position in real time during scanning, producing accurate point clouds without distortion — a major advantage.

Point cloud data captured with LRTK can be displayed in 3D on the smartphone for immediate confirmation. You can instantly measure the distance between two arbitrary points or view cross-sections to check ground shapes. There is no need to bring data back to a PC in the site office for analysis: you can complete the dimensional checks and volume calculations necessary for as-built management on the spot. If you use LRTK daily for as-built management, what used to take half a day for a current-condition survey and volume calculation can be completed quickly, dramatically improving work efficiency.

Furthermore, using LRTK Cloud, point cloud data can be uploaded and handled in a browser without specialist software. It is easy to overlay design data with point clouds to check discrepancies or to extract only the necessary parts of a point cloud for quantity calculations. LRTK answers the needs of site staff who want to “easily perform point cloud scanning themselves.” By enabling in-house digitization of current conditions without relying on specialists, LRTK significantly speeds up the site PDCA cycle.

On-the-Spot Checks with AR Construction Verification

One of LRTK’s revolutionary features is AR (augmented reality) construction verification. Until now, during construction, understanding discrepancies between the design and actual as-built conditions required comparing drawings or BIM/CIM models with the site and relying on imagination. With LRTK, you can overlay the design’s completed image directly on the site for visualization, making as-built management much more intuitive.

For example, imagine you are unsure whether anchor bolts or embedded pipes are positioned correctly in a reinforced concrete structure. Start the AR function of the LRTK app and display a previously imported 3D design model; the design model will be projected onto the site camera view at full scale and in the correct position (automatic alignment using LRTK’s high-precision coordinates eliminates the need for cumbersome markers or manual adjustments). By simply holding up the iPhone, you can see at a glance whether the rebar you are assembling matches the position in the design model. If there is a slight misalignment, you can correct it on the spot and prevent rework; if it is correct, you can proceed to the next process with confidence. AR can prevent construction errors caused by misreading drawings or dimensions.

AR construction verification improves quality and also aids communication among stakeholders. Because you can show the completed image on site, even non-experts can intuitively understand the space. For owners and site visitors, experiencing the completed image on site makes explanations and consensus-building smoother than with paper drawings. LRTK’s AR function acts as a “third eye” for site managers, simultaneously enhancing construction quality and stakeholders’ understanding.

Guide Staking Work Smartly with Coordinate Navigation

LRTK injects new life into staking (layout) work, which is essential on construction sites. Traditionally, staking to put stakes in the ground based on design coordinates involved surveyors using total stations to measure angles and distances while directing another worker; two-person teams were common. With LRTK’s coordinate navigation function, staking work becomes simple enough for anyone to perform.

The method is straightforward. Specify the coordinates of the planned stake-out points from the design in the LRTK app and start navigation. The smartphone screen then shows arrows and distance to the destination in real time, and the user moves accordingly. As you approach the target point, the distance display decreases, and when you arrive at the target the screen indicates “this is the specified location.” It guides you to the stake-out point much like a car navigation system guides you to a destination.

Switching to AR mode displays virtual stakes or markers on the ground, making it intuitive to identify where to place a stake. Even layout tasks such as marking out, which used to rely on veterans’ intuition, can be carried out with high accuracy regardless of experience when using LRTK’s coordinate navigation.

This function enables the tremendous benefit of completing staking work alone. Without worrying about staffing, you can perform layout as needed, allowing for rapid responses when additional points need to be set between processes. It also greatly reduces the risk of placing stakes in the wrong positions, preventing rework. LRTK’s coordinate navigation increases site autonomy and supports accurate, speedy staking.

High-Precision Layout Starting with iPhone Surveying

A new keyword created by the advent of LRTK is “iPhone surveying.” This literally means conducting surveying with an iPhone. Although using familiar tools — a smartphone and a small receiver — you can obtain coordinate data with accuracy suitable even for infrastructure work.

On site, even non-experts can perform various layout and verification tasks through iPhone surveying. For example, to confirm whether an excavation has reached the specified depth, the traditional approach involved setting up a level and having a surveyor measure heights, or using batter boards and height staffs for checks — a tedious process. With an LRTK-mounted smartphone, simply tap at the bottom of the excavation to record the elevation of that location. Construction management staff can check heights in real time and immediately determine “how many more centimeters to excavate,” allowing excavation to proceed safely and efficiently.

iPhone surveying is also effective for recording coordinates of new manholes or structures in roadwork. Previously, a surveying team would come after completion to record positions, but with LRTK, construction staff can sequentially measure coordinates of key points in parallel with construction. For routine inspections, site staff can immediately take photos with coordinates attached when they find points of interest. If the habit of anyone being able to measure on the spot takes hold, all kinds of site information will be visualized, enabling early error detection, easier sharing, and thorough quality control.

Additionally, iPhone surveying is powerful in disaster response. At landslide or flooding sites where you want to measure and record conditions before restoration, you can digitally record the damage without bringing in large equipment, using only an LRTK-equipped smartphone. Local governments are already beginning to use LRTK for on-site measurements during emergency response. The convenience of having surveying equipment ready in your pocket contributes to rapid situational awareness in emergencies.

How Sites Change with LRTK Adoption: Examples of Efficiency and Quality Improvements

Here is an example of how a site changed concretely after adopting LRTK.

At a certain medium-sized civil engineering site, LRTK is used for daily progress management. Previously, a specialist surveyor was called in once a week for as-built surveying to calculate fill or excavation volumes. After introducing LRTK, site staff began conducting point cloud scans themselves during their daily work and checking volumes on the cloud within the same day. As a result, the time spent on as-built management was reduced to less than half on a weekly basis, and daily changes could be accurately tracked without accumulated errors. Small discrepancies with the design were detected and corrected early, dramatically reducing rework and yielding better quality results.

At another building site, LRTK’s AR construction verification proved powerful during steel frame erection. An installed column was slightly out of position, but because the site supervisor was checking the design model overlay with AR, the deviation was discovered before welding and securing. Even deviations of a few centimeters that are hard to notice by eye appear clearly in AR, prompting immediate action. This prevented later rework and schedule delays, and stakeholders praised the tool, saying it “prevented a large loss thanks to early detection.”

In staking work as well, differences in performance between experienced staff and newcomers have diminished. Using LRTK’s coordinate navigation, even new workers can accurately set stake positions without bothering veterans. As LRTK spreads as a survey tool per person, it raises the baseline capability of the entire site and helps create a system where the whole team takes responsibility for quality control.

Expanding Possibilities with Simple Survey Functions

As introduced so far, LRTK is a reliable tool that enables anyone to practice advanced 3D construction. In addition, LRTK includes simple surveying functions that are useful in daily operations, and their application range continues to expand. Beyond complex 3D scanning and AR use, these functions simplify the act of “measure and record” itself and contribute to streamlining all sorts of site tasks.

• Ease of coordinate acquisition: With LRTK, single-point coordinate acquisition is astonishingly simple. For example, when you want to record the position of buried objects or points for as-built inspection, simply hold the smartphone over the point and tap to get an accurate coordinate. Acquired data is automatically plotted on a cloud map, enabling immediate sharing between site and office. Where coordinates were once written into notebooks and drawings, LRTK stores them digitally in real time and accurately.

• Photo geolocation records: The LRTK app has a photo geolocation function that takes photos and acquires positions simultaneously. When you photograph a point of interest on site, the photo is automatically tagged with the shooting position’s coordinates and direction. For example, if you photograph a crack during bridge inspection, it is saved with information such as “pier south side ○ m (○ ft) point, elevation ○ m (○ ft).” When you open the photo later on the cloud, you can immediately see where and in which direction it was taken in a 3D view. Photo geolocation links events on site to spatial information, making report preparation and sharing of problem areas much smoother.

• Monopod surveying for stability and efficiency: Using an optional lightweight monopod, LRTK enables more stable surveying. Mount the smartphone and LRTK receiver on the monopod, place the tip at the point to be measured, and measure; this reduces wobble compared to handheld operation and improves accuracy. A single person can easily operate the monopod, and the elevation offset (instrument height) can be corrected with one tap in the app. Surveying that formerly required two people can be performed efficiently by one person using a monopod, greatly benefiting small crews.

LRTK’s simple surveying functions are useful across a wide range of tasks, from minor daily measurements to inspections and reporting. By capturing all the “I just want to measure this” moments on site and enabling anyone to act immediately, LRTK not only improves convenience but also helps accumulate data that leads to advancing the construction PDCA and ensuring traceability for quality assurance.

Conclusion: The Future Job Site LRTK Opens Up

LRTK, which can be called the definitive solution for ICT construction, dramatically lowers the bar for 3D construction and is a strong partner for raising on-site capability. While “3D construction” once had an arcane, specialist image, LRTK has moved it into the realm of everyday operations. Keywords such as point cloud scanning, AR construction verification, as-built management, coordinate navigation, and iPhone surveying are becoming commonplace on sites through LRTK.

In future construction sites, the norm will be “a surveying smartphone per person,” acquiring and using needed information the moment it is required. As a driving force for DX (digital transformation) that enables everyone to participate, LRTK is leading the way. Why not introduce LRTK’s 3D construction and simple surveying to your site? The smartphone in your hand might be the key to transforming tomorrow’s construction sites.