Inflection Points Become Obvious at a Glance! AR Displays Revolutionize Field Surveying

Table of Contents

• The evolution of field surveying with AR technology

• Visualizing curve shapes and inflection points with AR displays

• Benefits AR brings to field surveying

• Start AR surveying with smartphone + RTK: simple surveying with LRTK

• Future outlook: how AR will change surveying

• FAQ

The evolution of field surveying with AR technology

In the construction industry, the introduction of digital technologies such as ICT construction and i-Construction has accelerated in recent years due to a shortage of experienced workers and the need to improve work efficiency. In the broader movement to promote DX in construction management—not limited to surveying—the adoption of advanced technologies like AR on job sites has also become more active. Among these, attempts to apply AR technology (Augmented Reality) to field surveying have attracted attention. AR is a technology that overlays digital information such as 3D models and text on real-world images seen through a camera. Once mainly used for research purposes, AR has evolved to a level usable in everyday field operations thanks to the improved performance of smartphones and tablets. The Ministry of Land, Infrastructure, Transport and Tourism is also encouraging the use of 3D technologies and AR to improve on-site productivity, and in response to this trend, AR surveying on job sites is becoming a realistic option. In fact, some local governments have begun introducing smartphone-based surveying systems, with examples showing effective rapid situation assessment and cost reduction in disaster recovery sites.

The advent of this AR technology is poised to dramatically change how field surveying is done. Traditionally, surveyors measured dimensions on site while referring to paper drawings, or performed setting out and verification by placing stakes or chalk marks on the ground. With AR, however, pre-prepared design data and drawing information can be projected onto the actual scenery, allowing surveying and verification tasks to be performed directly while viewing them on site. Information that was only understandable on drawings can be displayed full-size in place, turning work that relied on experience and intuition into something intuitive and easy to understand. For example, the location of road curves and inflection points, which previously could only be inferred by comparing paper drawings, becomes obvious at a glance with AR displays.

Visualizing curve shapes and inflection points with AR displays

Using AR, lines and points from drawings can be overlaid onto the actual site view. This makes it possible to visually grasp the shape of curves that previously could only be imagined from plan views or numeric data. For example, if centerline data for a road is projected onto the ground using a smartphone AR display, you can intuitively confirm the curvature and the positions of inflection points within the actual scenery. Because it appears as if a virtual line is drawn on the ground, there is no need to mentally visualize drawings in three dimensions to understand the finished curve shape on site. If designers and construction staff view the AR display together on site, it becomes easier to share recognition of where curves begin and where curvature changes occur, helping to prevent construction errors. Where staking or layout marking would have been required to indicate curve positions, replacing that process with AR displays can greatly simplify those positioning tasks.

Similarly, property boundary lines and building layout positions can also be displayed with AR. Compared to conventional methods that relied on boundary markers or temporary stakes to roughly estimate locations, visualizing boundary lines directly with AR clearly delineates the site extent on site so that all stakeholders can understand the situation at a glance. Even when boundary stakes cannot be found due to terrain or obstacles, virtual lines or points displayed on a smartphone screen make it easy to determine accurate positions. In scenarios where markers are buried by vegetation or snow, AR can digitally indicate those positions so anyone can find survey points without confusion.

It is also possible to overlay full-scale 3D models of planned structures onto the site scenery. For example, at a bridge construction site, displaying the planned girder model in AR can be a useful explanatory tool to convey the completion image to the client or neighboring residents. Scale and visual impact that are hard to grasp from drawings or renderings alone can be intuitively understood by viewing a 3D model overlaid on the actual landscape.

Additionally, virtual stakes or markers can be placed at specified coordinates and displayed in AR to guide users toward those points. Arrows or icons appear on the smartphone screen to provide navigation, so even inexperienced workers can reach target points without getting lost. This enables quick movement to staking locations or inspection checkpoints, eliminating wasted time spent searching for markers.

In this way, overlaying design information via AR realizes a state where things are “understood just by looking at the site.” Points that once relied on the intuition of experienced personnel become visible through digital guidance, reducing misalignment in understanding among technicians and enabling smoother consensus building. Since AR displays are combined with high-precision positioning data, once alignment is completed, virtual objects remain correctly located even as you move around a large site. Walking the site with a smartphone while lines and points are continuously shown in correct positional relation means that all key points, including inflection points, can be captured without omission.

Benefits AR brings to field surveying

AR displays bring various benefits to field surveying tasks. The main advantages are listed below.

• Intuitive visualization: Because drawing information can be projected full-size onto the actual site, even non-experts can intuitively understand the situation. A picture is worth a thousand words—showing something on site is faster and more accurate than explaining it on paper. When the client and site staff can all share the same image, misunderstandings decline and communication improves. Using a large-screen tablet for AR display makes it easy for several people nearby to look at the screen and confirm together.

• Improved work efficiency: AR enables surveying and as-built verification to be performed quickly on site, dramatically improving operational efficiency. For example, processes that previously required returning to the office to compare drawings with actual conditions can now be completed immediately on site. By proceeding with virtual markers displayed at necessary points, missed measurements or forgotten checks can be prevented. The labor involved in team staking or repeated measurements is reduced, allowing small teams to work quickly. As a result, processes like as-built inspections that once took days can be drastically shortened. In addition, measurement data and photos can be shared to the cloud on site, enabling supervisors or clients at remote offices to access real-time information and streamlining reporting tasks.

• Improved surveying accuracy and quality: AR guidance based on digital data reduces human measurement errors and recording mistakes. Because the discrepancy between the virtual model and the site can be checked in real time, errors can be corrected on the spot. For example, overlaying post-construction point cloud data on the design model and displaying it as a heat map makes it easy to intuitively see deviations from the design in color. This allows immediate detection of issues such as insufficient thickness or incorrect slopes, directly reducing rework and improving quality. AR displays that provide an overview of the entire space make it possible to uncover fine defects that were previously easy to overlook.

• Improved safety: In some cases, AR technology allows surveying in dangerous areas to be done safely. Points can be recorded from a distance and any missing parts checked later in AR without entering hazardous areas. If the locations of underground utilities are positioned beforehand and displayed in AR, the risk of accidentally damaging lifelines during excavation can be reduced. Furthermore, in high places or on unstable scaffolding, workers can check conditions from a safe distance through AR, reducing the need for awkward postures and contributing to worker safety. By making invisible things visible through AR, it also contributes to on-site safety management.

• Addressing labor shortages: Smartphone AR surveying is intuitive and easy to operate, so even inexperienced workers can handle it. Even if experienced surveyors are scarce, younger staff familiar with digital devices can perform surveying and measurements with a single smartphone. Since complex calculations and specialized knowledge are unnecessary, a surveying workflow that is less dependent on specific individuals can be built, helping to mitigate future labor shortage risks. Also, because points and reference lines are visualized by AR, it becomes easier to grasp coordinate systems and survey results, which is highly effective for training young engineers.

• Cost reduction: Traditionally, high-precision surveying required expensive dedicated equipment such as total stations or RTK-GNSS receivers, but AR surveying can utilize general-purpose smart devices, significantly reducing equipment costs. A single smartphone can handle positioning, measurement, recording, and verification, eliminating the need for multiple machines. For example, instead of purchasing and maintaining surveying equipment costing millions of yen, substituting with a smartphone and small devices can offer major cost advantages. Combined with time savings and rework reduction, comprehensive cost reductions can be expected.

Start AR surveying with smartphone + RTK: simple surveying with LRTK

To fully utilize AR technology on site, high-precision positioning is indispensable. A smartphone’s standalone GPS can have errors of several meters, which prevents accurate alignment. Enter RTK-GNSS (Real-Time Kinematic positioning), a technology that enables positioning with centimeter-level accuracy (cm level accuracy (half-inch accuracy)). Recently, devices that add RTK functionality to smartphones have appeared, and a representative solution is called “LRTK.” Even if the coordinate system of design drawings is unique, functions for localizing (aligning coordinates) to known points on site are provided, so overlays can always be displayed accurately.

With LRTK, the iPhone you normally use can turn into a high-precision surveying instrument. By attaching a small receiver weighing only a few hundred grams to your smartphone and launching a dedicated app, you can receive correction information from satellites and start centimeter-level positioning (cm level accuracy (half-inch accuracy)) instantly. Correction information is supported not only via internet-based base station data (VRS) but also by Japan’s quasi-zenith satellite system “Michibiki” augmentation signals (CLAS), enabling stable centimeter accuracy even at sites out of mobile coverage such as mountainous areas. No complicated settings or specialist knowledge are required, so anyone can start using it quickly. The smartphone displays the current positioning state and accuracy, and once stable, design drawings and model data can be overlaid on site with the AR function.

A major attraction of smartphone surveying utilizing LRTK is that positioning, recording, and AR-based verification are all completed with a single device. There is no need to set up a total station for positioning or open a PC to check drawings; surveying and checking can be done in real time while walking the site. Advanced uses—such as acquiring three-dimensional data of terrain and structures with point cloud scanning and comparing it with the design model on site—can also be operated intuitively within the smartphone app. Processes that used to require separate equipment and software can now be implemented seamlessly with just one smartphone, transforming the surveying workflow itself.

Feedback from the field includes comments such as “After introducing LRTK, young operators could use it without special training” and “Its simplicity makes it usable by anyone.” The app interface is visually clear, and users simply follow AR markers to move, so first-time users do not get lost. If users do have operational questions, online manuals and support desks are available for reassurance. This ease of bringing cutting-edge AR surveying technology to job sites as early as tomorrow is a major advantage of LRTK. The new method of smartphone RTK + AR is currently bringing transformation to surveying sites. Why not experience the evolution of field surveying through AR displays at your site?

Future outlook: how AR will change surveying

As AR technology advances further, it is expected that field surveying styles will change even more. Currently AR is mainly used on smartphones and tablets, but in the future smart glasses or helmet-mounted MR (mixed reality) devices may become widespread, allowing workers to view AR information hands-free. If design information and surveying data are always displayed where a worker is looking, work will proceed more smoothly than ever and safety will improve.

Moreover, closer integration with 3D design data (BIM/CIM) could enable advanced uses such as simulating construction procedures in AR on site or having AI highlight detected anomalies in real time on AR displays. It may also become possible to share AR images across multiple sites via the cloud and provide remote instruction and support. If these technologies become commonplace, the nature of surveying and construction management will be fundamentally transformed, enabling anyone to perform highly accurate work while digitally inheriting the expertise of experienced professionals. As described above, the future of field surveying with AR looks increasingly bright, and it is expected that such technologies will become standard in the near future. In short, a new era of surveying where people and digital tools cooperate is coming.

FAQ

Q: What are the benefits of introducing AR technology to field surveying? A: By using AR, information that is hard to understand on drawings can be visually confirmed on site, making surveying more efficient and sophisticated. Specifically, setting out and as-built inspections can be performed intuitively on site, shortening work time and reducing mistakes. These benefits dramatically improve surveying productivity. Also, because all stakeholders can view the same AR display and reach consensus, communication losses are reduced. For example, confirming boundary lines or design lines on site via AR can greatly reduce the time spent comparing site conditions with survey drawings.

Q: What equipment and preparations are needed for AR displays? A: Basically, you can start with a smartphone or tablet and a surveying app that supports AR. However, high-precision positioning is essential for accurate alignment, so using an RTK-GNSS receiver is recommended. Attaching a small device like LRTK to a smartphone enables centimeter-level positioning (cm level accuracy (half-inch accuracy)) and stable AR displays.

Q: Is AR-based surveying reliable in terms of accuracy? A: Yes. AR surveying combined with high-precision GNSS (RTK) is reliable in terms of accuracy. Conventional GPS errors were too large, but RTK reduces errors to a few centimeters. Virtual objects displayed in AR are placed based on these accurate coordinates, so they do not drift as you move around the site. With proper calibration and verification, AR surveying can be used in operations with accuracy comparable to traditional surveying methods. Reports are increasing from projects that introduced AR surveying and obtained results that meet conventional surveying standards.

Q: Can people who are not familiar with IT use it? A: If users are comfortable with smartphone operations, many can use AR surveying without special skills. Products like LRTK have simple UIs and clear guidance displays, so even sites using AR surveying for the first time can become proficient quickly. Reports from sites that introduced it indicate that both young and veteran engineers could understand it intuitively. Those initially hesitant about new technology often start actively using it once they experience its convenience on site.

Q: How do I introduce AR surveying to my site? A: First, prepare an AR-capable surveying app and a device that can obtain high-precision positioning. Purchasing equipment is one option, but for first-time users it is often better to use an easy-to-adopt service. For example, LRTK offers equipment rental and comprehensive support, allowing smooth introduction without specialist knowledge. Have site staff trial the tools in actual work and gather feedback while rolling out gradually to ensure the new technology is effectively adopted. Starting with a small-scale site for a pilot to confirm effects before full deployment is also an effective approach.