Why RTK AR? Strategic Advantages for the Construction and Surveying Industries

Surveying technology in the construction industry has advanced rapidly in recent years. Traditionally, surveying relied on total stations and GPS, but with the promotion of ICT and construction DX (digital transformation of construction), high-precision positioning using RTK-GNSS and drone surveying are becoming more common on sites. Among these, Real Time Kinematic (RTK) centimeter-level positioning is becoming an indispensable technology for civil construction management and as-built measurement. Recently, a new method combining RTK and AR (augmented reality) called RTK AR has emerged. By combining a compact high-precision GNSS receiver with a smartphone or tablet, high-precision field surveying and intuitive AR visualization become possible with a single handheld device. If all site staff are equipped with RTK-capable devices, the devices can be used as an all-purpose surveying tool that handles everything from point cloud measurement to visualization of design data, greatly contributing to labor savings and efficiency in surveying tasks.

This article explains RTK AR comprehensively—from how it works and the technical background, to the benefits of adoption, differences from conventional technologies, and concrete use cases such as surveying work, as-built management, design data visualization, stake-driving guidance, boundary confirmation, and 3D point cloud integration. Finally, we introduce the simple surveying and AR display features of LRTK, a cutting-edge construction DX solution, as practical hints for on-site adoption.

Table of Contents

• What is RTK AR?

• Differences from Conventional Technologies

• Benefits of Introducing RTK AR

• Main Use Cases of RTK AR

• Points and Precautions When Introducing

• Conclusion

• FAQ

What is RTK AR?

To understand RTK AR, first organize the components: “RTK positioning” and “AR display.” After grasping the basics of both, let’s look at the new possibilities created by their fusion.

What is RTK positioning

RTK positioning is a GNSS (satellite positioning system) technique that obtains high-precision positions in real time. Standalone GPS positioning typically has errors of several meters and is insufficient for precise surveying, but RTK uses a base station (a receiver fixed at a known position) and a rover (a receiver connected to a worker’s device) to observe satellite signals simultaneously and sends correction information from the base station to the rover to correct errors. This can boost positioning accuracy to the centimeter level. According to materials from the Geospatial Information Authority of Japan, standalone positioning can have deviations of several meters, whereas RTK-GNSS has been reported to keep errors within a few centimeters. Recently, network RTK (e.g., VRS) that obtains correction data over the Internet without placing a base station, and Japan’s quasi-zenith satellite Michibiki’s CLAS (Centimeter Level Augmentation Service) have made high-precision positioning more accessible. Today, the use of multiple satellite systems (not only GPS but also GLONASS and Galileo) and multiple frequency bands helps maintain centimeter-level positioning even in obstructed environments. Real-time RTK positioning is increasingly used for infrastructure measurement and machine guidance accuracy control, and it has become a foundational technology indispensable to civil engineering and surveying sites.

What is AR (augmented reality) technology

AR (Augmented Reality) overlays CG models or text information on the real-world view through a smartphone, tablet, or smartglasses. Because 3D design models and instruction information can be composited into the scenery in front of you, you can virtually “augment” the real space. AR use in construction has begun: for example, stakeholders can share a model of a completed structure superimposed on live site footage, or piping routes drawn on paper plans can be projected onto real structures for confirmation during installation. Traditionally, site personnel had to imagine the finished form from 2D drawings, and mismatched understanding could lead to rework. With AR, if you can intuitively share the completed image, it greatly helps prevent mistakes and improves communication efficiency. Recently, combining BIM/CIM 3D design data with AR has allowed transparent displays of pipes and buried objects that will be hidden after finishing, aiding inspections and planning of subsequent works. In this way, AR is increasingly valuable as an information-sharing tool on construction sites.

Benefits of combining RTK and AR

What can be achieved by fusing high-precision RTK positioning with AR display? The key point is that you can realize AR displays that align stably based on coordinates. Typical smartphone AR requires marker placement or plane detection (surface recognition) as initial alignment to correctly overlay CG models on site footage. However, as users move, camera tracking errors cause the model’s position to gradually drift, making precise alignment difficult. If AR display is performed while continuously obtaining centimeter-level self-position coordinates with RTK-GNSS, virtual models can be placed directly at absolute positions in the surveying coordinate system, so the model will remain aligned with reality even as the user moves around. In other words, AR that is linked to surveying coordinates and requires “no alignment” becomes possible. You can skip cumbersome alignment tasks: simply select the design data in the app and the model is instantly displayed at the correct position. For example, for a structure to be installed in dense undergrowth with poor visibility, RTK AR can pinpoint the installation position visually. Markers on the screen make it immediately clear “where to stand.” Because RTK also provides high-precision information about device orientation (bearing), the virtual model’s position and orientation remain stable and accurate even when the user walks around and views it from different angles.

Introducing absolute coordinates into AR also enables seamless linking of design data and field survey information. Since coordinate values in design drawings or CAD (such as public coordinate system XYH) match the coordinates of survey points or models obtained by RTK AR, you can overlay drawing data and the real world directly without cumbersome coordinate transformations or on-site calibration. This feature enables consistent digital data use from surveying through design and construction, dramatically streamlining on-site verification and instruction. RTK AR thus represents a next-generation smart construction solution born from combining high-precision positioning technology with AR visualization.

Differences from Conventional Technologies

To understand how RTK AR changes the jobsite, let’s compare it to traditional surveying and construction management methods. Traditionally, experienced surveyors operated optical surveying instruments (total stations, etc.) with assistants to set up reference stakes (wooden stakes for layout) and observe latitude/longitude and elevation at various points. These surveying tasks were labor- and time-intensive and sometimes forced work to pause until surveying was completed due to weather or terrain conditions. Creating drawings and compiling reports from survey results also took time when done manually. Additionally, construction personnel often misimagined the finished form due to the gap between 2D drawings and the actual site, leading to rework later.

With RTK AR, however, many surveying and layout tasks can be performed efficiently with fewer people. Using the simple setup of a smartphone plus a GNSS receiver, positions that used to rely on veteran intuition can be determined intuitively. For instance, where it used to be necessary to drive stakes on site while referring to plans, RTK AR can navigate by AR-displaying the design position on the device screen, allowing accurate location determination even if you omit the traditional reference stake process. Additionally, quality checks that previously required a surveying crew to measure as-built conditions after construction can be done on the spot by overlaying the design model on live site footage and detecting deviations immediately. The sequential process of “measurement → recording → verification” that was previously split into multiple steps can be conducted concurrently on site with RTK AR, leading to major time savings and reduced rework.

Another major difference is that you don’t need to procure multiple expensive specialized instruments. Professional devices like total stations or 3D laser scanners can cost several million yen apiece, but combining a small RTK-capable GNSS receiver with a commercial smartphone allows relatively low-cost introduction. If every site worker has a device and can independently use high-precision positioning and AR functions, delays caused by “waiting for surveying” can be eliminated. In this way, RTK AR is a next-generation site tool that overcomes the challenges of traditional methods while balancing accuracy and efficiency.

Benefits of Introducing RTK AR

Here are the main benefits you can obtain by introducing RTK AR.

• Reduced manpower and improved work efficiency: High-precision positioning and AR navigation enable many surveying and layout tasks that previously required multiple people to be performed by one person. Reducing the effort of setting reference stakes, lowering rework, and simplifying setup can dramatically shorten the time and labor required for surveying and construction management. This helps maintain productivity on sites facing labor shortages and contributes to work-style reforms.

• Intuitive and simple surveying operation: Operations that once required specialized knowledge are made accessible through clear UIs on smartphone and tablet apps. With visual guidance from AR displays, even less-experienced staff can perform accurate positioning and measurement. This reduces the burden on skilled technicians and helps with skill transfer to younger workers.

• Real-time on-site verification and information sharing: Since design models and measurement data can be displayed in AR on site, verification and decision-making can be performed immediately. Deviations in as-built conditions can be detected and corrected on the spot, and progress can be shared with stakeholders in real time. Early detection of mistakes and reduced rework follow, and cloud synchronization enables smooth remote collaboration between the site and the office.

• Cost reduction: High-precision surveying and AR display can be achieved simply by combining a smartphone and a small GNSS receiver, reducing the need for expensive surveying equipment and large volumes of paper drawings. Equipment and material costs can be lowered, and rental and outsourcing of surveying may be reduced. Because a single device can serve multiple purposes as an “all-purpose surveying instrument,” operational costs are also improved.

• Improved safety: AR enables non-contact, non-face-to-face surveying and instructions, minimizing entry into hazardous areas. For example, surveying on steep slopes or at height can be done by pointing the camera from a safe distance to acquire coordinates, ensuring worker safety. Fewer personnel on site also reduces the risk of contact with heavy machinery.

• Data integration and promotion of construction DX: Positioning data and captured images obtained with RTK AR are stored and shared digitally, and can be used directly for comparing with 3D design data and creating as-built documentation. Reducing paper-based exchanges and centralizing information management makes it possible to concretely promote construction DX. This aligns with the Ministry of Land, Infrastructure, Transport and Tourism’s recommended *i-Construction* initiative, and in some cases may qualify for subsidies that further encourage adoption.

Main Use Cases of RTK AR

Next, let’s look at representative use cases that show how RTK AR can be applied on site.

Use in surveying work

RTK AR can greatly improve efficiency in everyday topographic and as-built surveying. Simply walking around the site with an RTK-capable smartphone allows you to sequentially acquire three-dimensional survey point data aligned with the public coordinate system. Even on uneven terrain, combining the phone’s built-in LiDAR scanner or camera enables rapid capture of wide-area point clouds, and absolute coordinates are assigned to the captured point clouds in real time. This allows creation of survey maps and terrain models without complicated post-processing, making the workflow much more efficient. Establishing benchmarks or surveying known points also becomes easier. If you register the coordinates of known points set on the site in the app, you can confirm a location by simply pointing the smartphone at it and take photos with coordinate annotations as records. When installing new benchmarks, AR can display the target coordinates on the ground while you drive a stake, improving both speed and accuracy. Because survey data can be shared immediately via the cloud, coordinates captured on site can be reflected in office CAD drawings in real time. In this way, RTK AR seamlessly connects the entire surveying workflow from observation to drawing creation, enabling anyone to perform simple surveying easily and making it a powerful tool.

Use in as-built (construction) management

As-built management is the quality control task of measuring and recording whether completed structures or earthworks conform to design shapes and dimensions. RTK AR brings substantial efficiency gains to as-built management through real-time capability. Traditionally, surveys were performed after construction completion and points’ elevations and cross-sections were compared to design drawings in a post-check workflow; if defects were found, rework on site was necessary. With RTK AR, you can immediately check as-built conditions right after construction. For example, after paving or embankment work, you can use a smartphone’s 3D scan function to capture the ground point cloud and automatically generate a heat map (a color-coded diagram showing elevation differences) by overlaying it with the design model in the cloud. Downloading that heat map to your phone and displaying it in AR on site makes it easy to see higher or lower areas at a glance. Instead of looking up individual point values on drawings to find defects, colored areas on AR display indicate deviations visually, enabling instant corrective work. For structural inspections, projecting virtual objects that guide design dimensions in AR allows pass/fail judgments to be completed on the spot. For example, in tunnel or bridge inspections, projecting a wireframe model that indicates required clearance makes it possible to confirm compliance on site. Inspection results can be saved as screenshots or measurement data and used directly in as-built documentation. RTK AR thus converts as-built management from a reactive post-process to a real-time process, considerably reducing the time and effort required for quality assurance and raising overall construction quality.

AR visualization of design data

One of the most intuitive applications of RTK AR is the on-site visualization of design data. Overlaying design information from drawings or BIM/CIM models onto the actual site creates significant advantages. For example, on an earthworks site, displaying the designed finished ground model in AR lets you see at a glance where and how much excavation or fill is needed to reach the planned shape. Operators can perform work visually rather than relying on intuition if differences between the actual ground and the finished model are shown on a tablet by color or form. Similarly, displaying design longitudinal profiles for road work in AR on the ground allows constant comparison between current and planned elevations, enabling on-the-spot correction of deviations. In short, RTK AR makes it possible to “visualize” finished shapes and errors that are hard to grasp on flat drawings, leading directly to reduced mistakes and optimized work.

Use for stake-driving and layout

RTK AR is also highly useful for frequent stake-driving and layout tasks in civil and building construction. Stake-driving involves placing stakes or markers at specified coordinate positions. Traditionally, a surveyor used a total station to set a location, and another worker drove a stake at the indicated point. With RTK AR, stake-driving can be performed with AR navigation. If you load a coordinate list of stake positions into the system beforehand, site personnel can select a point and see arrows or markers on the smartphone screen and receive real-time guidance such as “Target is NE 0.12 m.” The worker adjusts their position according to the screen and drives the stake at the specified position. Compared to using tape measures or laser layout devices, stake-driving becomes much faster and more accurate. For floor layout marking on concrete slabs, AR can project guideline lines and shapes to assist marking. Display wall positions or piping routes on the floor via AR and mark along those lines to complete complex layout tasks single-handedly—saving time otherwise spent frequently consulting drawings or setting up tripods for laser devices. Displaying virtual reference stakes or string lines in AR creates a shared “invisible benchmark” for all on site. For example, displaying the design excavation bottom surface as a virtual plane in AR before excavation helps machine operators intuitively know how deep to dig. Rather than reading numbers on reference stakes, AR lets workers visually grasp reference standards and reduces errors. This “virtual reference stake” capability is enabling labor-saving construction that omits physical stakes or string lines traditionally considered essential.

Use for boundary confirmation

RTK AR is powerful for land surveying and boundary inspections. Traditionally, temporary markers like wooden stakes or plastic tape were used to indicate parcel boundaries, or transit instruments displayed extension lines. Such methods can be hard to visualize on site and difficult to share accurately with all stakeholders. Using RTK AR, predefined boundary coordinates can be visualized on site as virtual line segments. For instance, if you register neighbor boundary coordinate groups from a cadastral map in the system, you can draw the boundary line on the ground like a virtual fence via AR. All attendees in a boundary inspection can view the same boundary line through smartphones or tablets, making it immediately clear “where the property starts and ends.” This is highly effective during land negotiations or boundary disputes: visual presentation helps prevent misunderstandings and facilitates smooth agreement. When searching for boundary markers, surveyors can be guided to stored known boundary points by AR navigation, preventing missed stakes hidden in grass or brush. AR also applies to locating buried structures. If GIS data shows the routes of buried water, sewer, or cable lines, rendering those polylines in AR lets you “see through” the ground to reveal unseen piping routes. In road excavation work, pre-visualizing buried utilities in AR helps machine operators intuitively understand where to be careful, enhancing safety. For municipal infrastructure management, AR simplifies confirmation of underground utilities that previously suffered from drawing–as-built discrepancies, improving maintenance efficiency.

Integration with 3D point cloud data

RTK AR is also a powerful tool for utilizing on-site 3D data. Recently, 3D point cloud data from terrestrial laser scanners and drone photogrammetry has begun to be used in construction management, and RTK AR pairs well with the acquisition and use of such point clouds. In terms of data acquisition, RTK AR makes point cloud capture with absolute coordinates easy. Point clouds scanned by a phone or tablet camera or LiDAR are normally recorded in the device’s local coordinate system (relative coordinates). By combining scans with the high-precision position information from RTK, captured point groups can be immediately assigned geodetic coordinate values, allowing scan results to be placed directly on public coordinate maps or CAD drawings. For example, when measuring a bridge pier with a laser scanner, you previously had to later align the point cloud to known points by translating the entire cloud; with RTK AR, point clouds can be created in an already-aligned coordinate system, greatly reducing post-processing. For data utilization, overlaying captured point clouds or existing 3D design models in AR enables intuitive comparison and analysis. The heat map visualization mentioned in as-built management is one example, but you can also switch between pre- and post-excavation point cloud models in AR to verify how many meters were excavated at each location in the presence of stakeholders. Some systems can immediately calculate and display volumes from point cloud differences, making on-site earthwork quantity management feasible. In disaster response, integrating 3D point clouds and AR is also gaining attention. For instance, at a landslide site, overlaying pre- and post-disaster point clouds on site can quickly estimate collapsed volume and identify secondary hazard areas. Point clouds captured at the disaster site can be shared via the cloud so remote headquarters can assess the situation through AR. RTK AR therefore transforms point cloud data from mere records into a “visualization” tool on site, maximizing the value of the data.

Points and Precautions When Introducing

While RTK AR is highly useful, there are several points to note when introducing and operating it. Here are the main considerations.

• Use equipment appropriately according to purpose: RTK AR achieves centimeter-level positioning, but in situations requiring millimeter-level accuracy (e.g., precise installation of structures or measurement of tiny displacements), optical surveying instruments such as total stations are still more suitable. It is important to combine conventional methods appropriately according to the required accuracy.

• Dependence on GNSS reception environment: RTK positioning requires a sufficient satellite reception environment (clear sky view). In canyons of high-rise buildings, forests, or tunnels, satellite signals may be interrupted or multipath effects may occur, leading to significant accuracy degradation or failure to obtain a Fix solution (integer solution). In such environments, corrective strategies such as using local coordinate offsets from nearby known points or fixing a high-precision position once and switching to relative positioning in an indoor mode can be effective. For critical survey tasks, it is also advisable to periodically perform known point checks to confirm that positioning accuracy has not drifted significantly.

• Handling of equipment and power management: When using smartphones and GNSS receivers on site, take care to protect equipment against dust, water, and drops. General smartphones are not as rugged as dedicated surveying instruments, so use protective cases, straps, and waterproof housings for rainy conditions. Also, when operating all day, smartphone and receiver batteries deplete quickly, so prepare spare batteries or mobile power supplies and charge as needed.

• Coordinate system alignment: Construction surveying in Japan uses various coordinate systems, such as the plane rectangular coordinate system or local coordinate systems with arbitrary origins. When introducing an RTK AR system, confirm that it can handle your organization’s coordinate systems and vertical datums (e.g., geoid heights). Many systems support the Japanese Geodetic Datum (JGD2011) and geoid heights and provide functions to set site-specific coordinate origins and bearings. During implementation, set coordinates correctly to match your workflow and ensure consistency between design data and positioning data. Misconfiguration may cause the AR display to be off by several meters despite correct setup.

• Initial introduction and training: Successful adoption of new technology requires training for site staff and a trial period. Start with a small-scale project to let staff become familiar with operations, and prepare operational manuals and internal rules. Follow-up for staff unfamiliar with digital tools is also important. Fortunately, RTK AR centers on intuitive actions like “move while looking at the AR screen,” so it is relatively easy to learn, but it is still important to educate users on positioning principles and data-sharing procedures. By paying attention to these points in operation, you can maximize the benefits of RTK AR. Appropriately using the technology within its technical limits will also enable higher safety and quality control than before.

Conclusion

RTK AR combines satellite-based high-precision GNSS surveying with AR display to bring transformative changes to construction and surveying sites. Reports from the field indicate many benefits, including alleviating labor shortages, dramatic improvements in work efficiency, real-time quality checks, and smoother information sharing among stakeholders. As efficiency and digitization are demanded in today’s construction industry, RTK AR is becoming a new standard in surveying and construction management.

One tool that easily provides both simple surveying and AR visualization is the smartphone-compatible high-precision GNSS solution “LRTK.” By adopting LRTK, anyone can achieve centimeter-level positioning and intuitive AR overlay on a handheld smartphone, dramatically improving on-site surveying accuracy and work efficiency. If you are interested, please check details at the [LRTK official site](https://www.lrtk.lefixea.com/). Embrace cutting-edge RTK AR technology to realize smart site operations where accuracy and efficiency coexist.

FAQ

Q: What equipment is required to introduce RTK AR? A: Basically, you need a smartphone or tablet used on site and a small GNSS receiver (RTK-capable antenna) that supports centimeter-level positioning. The GNSS receiver connects to the smartphone via Bluetooth or cable to receive satellite correction information (RTK differential data) for real-time positioning. You also need a communication environment (mobile data or pocket Wi‑Fi) to obtain correction information over the Internet if using network corrections. Dedicated apps or software are required to acquire data from the GNSS receiver and display AR, but an integrated hardware-and-software solution like LRTK can simplify adoption.

Q: How accurate is positioning with RTK AR? A: Typical RTK-GNSS positioning can achieve about 1–2 cm (0.4–0.8 in) in horizontal position and a few centimeters (a few in) in height. RTK AR offers comparable accuracy for determining your position and measurement points and for AR display. This accuracy is sufficient for many surveying and as-built verification tasks in civil engineering. However, for ultrahigh precision at the millimeter level, traditional equipment such as total stations with EDMs remains appropriate. It is ideal to combine RTK AR and conventional methods according to the application.

Q: Can RTK AR be used in places where GNSS signals cannot reach, such as forests or tunnels? A: Unfortunately, in environments where satellite signals cannot be received, RTK AR’s high-precision positioning cannot function. In forests or areas with building shading, positioning may be possible but with temporary accuracy degradation; in deep tunnels where reception is impossible, RTK cannot determine self-positioning. In such cases, complement with other methods such as offset measurements from pre-acquired known points or terrestrial laser scanning. Some systems include an indoor mode that uses an accurately acquired position as a starting point and then continues relative positioning via inertial sensors for short durations in GNSS-denied areas. However, for long-duration or wide-area GNSS-denied situations, RTK AR alone is insufficient, and combining conventional techniques is realistic.

Q: Can RTK AR completely replace conventional surveying equipment? A: RTK AR can streamline many surveying and layout tasks, but it is more of a complement than a full replacement for existing equipment. Routine topographic surveys, as-built checks, and stake-driving can be greatly simplified with RTK AR, but precise measurements requiring millimeter accuracy or surveys in GNSS-denied complex environments still require traditional total stations, levels, and similar instruments. Sites are beginning to operate by combining RTK AR where applicable to boost productivity and immediacy, and using conventional instruments for challenging measurements—this flexible approach is best.

Q: I’m concerned whether site staff can use it. Is it difficult to learn? A: Many RTK AR systems prioritize intuitive operation, and using app guidance on a smartphone or tablet makes them relatively easier to learn than specialist instruments. For example, while total stations required specialized knowledge and experience, RTK AR often guides users to target positions by simply following on-screen arrows or models. Nonetheless, initial training and an on-site trial period to teach basic usage and precautions are recommended. Because AR is visual, operations tend to be grasped quickly. Sharing manuals and knowledge internally and addressing questions during the learning phase will help site staff master the tools.

Q: How should I evaluate the cost-effectiveness of introducing RTK AR? A: Costs of introducing RTK AR include purchasing high-precision GNSS receivers, subscription fees for correction services if needed, and license fees for dedicated apps or systems. On the other hand, you may reduce the need for multiple conventional surveying instruments and the frequency of outsourcing surveys, producing cost savings. More importantly, time cost reductions from improved productivity and reduced rework can yield substantial economic benefits. Shortened schedules and fewer fixes often produce returns that exceed the initial investment. Taking advantage of subsidies and measures supporting new technology adoption—such as those related to the Ministry’s *i-Construction* initiative—can further improve cost-effectiveness. While results vary by site, RTK AR is often a sound mid- to long-term investment.