Prevent Boundary Disputes in Advance! Display Boundary Lines on Site with AR

Table of Contents

• Causes and challenges of boundary disputes

• On-site visualization of boundary lines using AR technology

• On-site verification by displaying drawing data in AR

• Safety checks by displaying underground buried objects in AR

• Benefits brought by AR utilization

• Recommendation for simple surveying using LRTK

• FAQ

Causes and challenges of boundary disputes

On land and construction sites, it is extremely important to accurately grasp the boundary of your property or the scope of work. If the boundary line is clearly indicated, ensuring the safety of the work area and forming agreements with neighbors proceeds smoothly. However, when the boundary is ambiguous, it can lead to unexpected trouble. For example, boundary stakes (boundary markers) that indicate the boundary may be damaged or lost due to aging or construction, or there may be discrepancies between the boundary lines on drawings and local recognition, resulting in situations where people often don’t know “where their land ends.” As a result, trees may be mistakenly cut down beyond the boundary, temporary fences or material storage areas may be expanded more than necessary, and these actions can later escalate into disputes with adjacent landowners.

If boundaries remain unclear, it becomes difficult for contractors to accurately understand the work area, leaving concerns about safety and schedule management. When discrepancies in recognition among stakeholders occur—such as “the drawing shows it should be up to here, but it looks different on site”—communication loss follows and construction can be impacted. Especially in the national land parcel surveys being carried out across Japan to reconfirm old boundaries and areas, some regions still have unresolved boundaries (so-called places with undetermined parcel boundaries), making boundary confirmation work difficult. Traditionally, experienced surveyors would compare drawings with the site and indicate boundaries with stakes or ropes, but this method takes time and effort and makes it hard to share the boundary image with all stakeholders.

Boundary disputes are not uncommon, and in the worst case can lead to litigation and significantly disrupt construction. That is why it is important to accurately confirm boundaries in advance with all stakeholders and eliminate misunderstandings.

A promising new approach to solve these challenges and prevent boundary disputes in advance is to use AR (augmented reality) technology to display boundary lines on site.

On-site visualization of boundary lines using AR technology

AR is a technology that overlays digital information onto real-world scenes captured by a smartphone or tablet camera. Applied to invisible boundary lines or points, it can draw virtual boundary lines on the screen. However, ordinary GPS has meter-level errors, so simply pointing a smartphone at the site cannot display boundary lines at precise positions. The key to solving this is the high-precision satellite positioning technology called RTK (Real Time Kinematic). Using GNSS with RTK can reduce satellite positioning errors to the order of a few centimeters (a few in). By attaching a dedicated compact GNSS receiver to a smartphone or tablet, or by using network RTK services that utilize the Geospatial Information Authority of Japan’s reference stations, high-precision self-positioning can be obtained even at outdoor sites.

By combining this accurate current position from RTK positioning with the intuitive visual display of AR, boundary lines that were previously invisible can be overlaid on the site scenery. If you load coordinate data of boundary points obtained from prior surveying into an AR-compatible surveying app, the four corners of an actual lot and boundary lines with neighboring land can be drawn on the smartphone screen as glowing virtual lines or virtual stakes. Users can walk along the line displayed on the screen, make markings at accurate boundary points, or confirm the boundary location on site together with stakeholders.

The point that supports this mechanism is the alignment (calibration) that matches the coordinate system of the digital data with the coordinates of the actual site. Ordinary AR displays that rely only on a smartphone’s built-in gyrosensor or image recognition can experience positional drift and cause virtual objects to float. However, by obtaining self-positioning based on a public coordinate system via RTK and, as needed, adjusting the AR space at a local known point, it is possible to achieve high-precision displays where virtual boundary lines exactly match ground positions. For example, by scanning the surroundings with the LiDAR scanner built into the latest iPhones and aligning point cloud data with reference points and design data, the device’s local coordinates can be matched with geodetic coordinates. With correctly calibrated AR, the boundary line display will remain accurately fixed to the ground even as the device moves. In short, AR can reproduce the boundary image that experienced surveyors have in their heads in a form that anyone can share on site.

On-site verification by displaying drawing data in AR

AR technology can be used not only for land boundary lines but also to overlay design drawing data on site. For example, at a construction site, if lines from prepared plans or CAD design data are displayed on the ground in AR, discrepancies such as “it should be straight on the drawing but the alignment is off on site” can be discovered quickly. Displaying planned lines for temporary enclosures or temporary yards in AR before construction enables three-dimensional verification of planned layouts that are hard to imagine from paper drawings alone. This helps prevent situations like “we found out after installation that there wasn’t enough space” and allows all stakeholders to share the completed image.

In fact, on one land development project, the finished model of the embankment and 3D models of construction machinery were displayed in AR so that all workers could confirm the finished appearance. The virtual heavy equipment models visualized distances and working radii relative to the surroundings, aiding safe placement planning.

In roadwork and land development sites, visualizing the design centerline and elevation references in AR during the design stage lets workers keep the correct lines in mind during construction. Position information that was traditionally indicated by batter boards or reference strings can be intuitively understood via glowing lines on AR, so you can immediately check whether the as-built form (as-built) matches the design even without surveying instruments. Reducing the time spent comparing drawing data with the actual condition and preventing measurement or misreading errors are major advantages.

AR is also useful for comparing design shapes with the current state during construction. For example in tunnel work, overlaying the design model on the current excavation allows immediate confirmation of whether excavation has reached the planned line. Similarly, in road construction, you can check on site whether the subgrade height and slope match the drawings, helping ensure construction quality. Tasks that used to require physically matching scales on site for as-built verification can be done more efficiently and accurately with AR.

Safety checks by displaying underground buried objects in AR

AR excels at visualizing information that is usually invisible. Therefore, it is also attracting attention as a means to share the location information of underground buried objects such as pipes and cables on site. For example, if route data of buried water and sewage pipes or gas pipes are displayed in an AR-enabled map app, the smartphone screen can virtually draw the lines of pipes running beneath the ground. Visualizing the positions of buried pipes in AR before excavation reduces the risk of accidentally damaging pipes and leads to safer construction. It is also possible to display underground manhole structures or the routes of power lines as 3D models on roads, making AR an intuitive information-sharing tool for maintenance operations.

Traditionally, confirming buried objects required referring to drawings or estimating positions with detection equipment. But AR displays can visualize piping routes from drawings directly on the ground, enabling workers to grasp at a glance that “a pipe runs 〇 m (〇 ft) below here.” When underground obstacles that require caution exist, proceeding with construction while confirming positions in AR in advance greatly contributes to preventing accidents caused by human error. AR can also be used as a navigation tool to reach survey points that are difficult to identify from the surface. If arrows or routes are displayed on the smartphone screen toward the target point, complex terrain can be navigated accurately, improving the efficiency of surveying and inspection tasks.

Benefits brought by AR utilization

Displaying boundary lines and drawing data on site with AR brings many benefits to the field. Here are the main advantages summarized.

• Improved visibility: Boundary lines and design lines that were not easily seen from paper drawings or ground stakes can be displayed as bright glowing lines in AR, making them visible from a distance. Boundaries hidden by vegetation or obstacles become immediately clear when lines are projected through a smartphone.

• Smoother consensus building: AR is powerful for explanations to clients and nearby residents. The completed image or boundary position that is difficult to convey with drawings alone can be intuitively understood by overlaying virtual models or lines on the actual scenery. Because all stakeholders can view the same AR image and confirm “this is the boundary” or “a structure will be built at this location,” misunderstandings that lead to disputes are reduced and consensus building is smoother. For example, at a pre-construction briefing for a bridge, displaying a life-size 3D model of the planned bridge in AR at the construction site allows immediate sharing of the impact on scenery and surrounding environment. Showing the completion image visually prevents misunderstandings like “this wasn’t what we expected.”

• Improved safety and quality: Misrecognition of boundaries or design lines can lead to serious accidents or construction mistakes. If you can compare design information with the current state in real time using AR, workers can notice deviations and correct them immediately, improving both safety and quality control. For example, if heavy equipment is about to cross a boundary, the on-screen line display lets operators notice and prevent an overrun accident. Also, if rebar is placed in a different location than shown in drawings, it can be identified and corrected on the spot, reducing quality defects.

• Improved work efficiency: The ability to display virtual lines and virtual stakes means reducing the physical work of driving boundary stakes or stringing lines. Surveying and layout tasks that used to require two-person teams can be completed by one person using an AR app. Virtual stakes can indicate positions in places where physical marks cannot be made, enabling safe surveying in high or hard-to-access areas. Reducing the effort for driving or removing stakes saves overall work time and cuts costs.

• Ease of skill acquisition: Operating advanced surveying equipment used to require experience, but AR surveying with a smartphone is intuitive for younger staff as well. Because you simply follow on-screen guides, it is easy to use even without specialist knowledge, helping mitigate the shortage of skilled field technicians. Reducing task dependence on individuals through digital technology will also be beneficial for future skill transfer.

Recommendation for simple surveying using LRTK

Realizing AR visualization of boundaries and high-precision positioning may seem to require specialized equipment like GNSS receivers and compatible apps, but in recent years these tools have become compact and easy to use. Our LRTK series provides a smartphone-based high-precision positioning solution. By attaching a small antenna receiver to a smartphone and launching the LRTK app, the device functions as surveying equipment, making measurement of boundary points and AR display of boundary lines simple. Because you can introduce it by combining the smartphones or tablets already on site with the LRTK solution, high-precision AR surveying can be implemented even on small- to medium-scale sites without purchasing expensive specialized equipment. In addition, these smart construction initiatives align with the Ministry of Land, Infrastructure, Transport and Tourism’s “i-Construction” policy, and digital technology adoption is advancing across the construction industry.

By using the LRTK series, the AR display of drawings, boundaries, and buried objects introduced in this article can be realized smoothly. Preconfigure and share boundary coordinates and design data in the cloud, and simply point a smartphone on site to instantly display virtual lines. Digitalizing cumbersome surveying tasks not only helps prevent boundary disputes in advance but also contributes to productivity improvements through on-site DX (digital transformation). Try LRTK to experience improved efficiency in boundary confirmation and as-built management. Actively utilizing AR technology will help achieve safe and smooth site operations without boundary disputes.

FAQ

Q: What is required to display boundary lines in AR? A: For AR display you need an AR-capable smartphone or tablet, a high-precision GNSS receiver (RTK), and coordinate data for the boundaries or drawings. For example, by connecting an RTK-compatible antenna to an AR-capable iPhone or Android device and loading boundary point coordinates into a dedicated surveying app, you can visualize AR boundary lines on site. Using our LRTK series, surveying and AR display can be achieved with just a smartphone.

Q: How accurate are boundary lines displayed in AR? A: With RTK, boundary lines can be displayed with an error on the order of a few centimeters (a few in). Unlike conventional GPS that can be off by several meters (several ft), if calibration is done correctly the virtual line on the screen will not be misaligned with the actual boundary. However, high-precision positioning requires sufficient satellite signal reception, and errors may be slightly larger depending on the surrounding environment.

Q: Can buried pipes and the like underground be made visible in AR? A: Yes, if the location information of buried objects is known in advance, they can be displayed in AR. For example, by preparing drawings of water or gas pipes and importing them into an app, you can indicate pipe routes on the ground as virtual lines or 3D models. Buried objects that are not visible to the naked eye can be shared with all workers by showing their positions in AR, aiding safety checks.

Q: Is operating AR surveying difficult? A: Even those who have never handled specialized surveying equipment will find AR surveying relatively easy. You just follow the guides displayed on the smartphone or tablet screen, so it’s intuitive to use. Surveying and layout tasks that previously required experience are becoming digital tasks anyone can handle through AR.

Q: Can it be used in mountainous areas without network coverage? A: There are methods for performing high-precision RTK positioning even where internet communication is unavailable. In Japan, using supplemental signals from the “Michibiki” quasi-zenith satellite (CLAS) enables centimeter-level positioning (half-inch accuracy) without communication with a base station. Also, if there are known reference points on site, correcting the AR space to those points allows accuracy to be maintained offline. Therefore, in forested or mountainous areas, AR boundary display can be used provided data is prepared in advance.

Q: In what sites or industries is AR boundary display being used? A: It is mainly being used in civil engineering, building construction sites, and land surveying. It is introduced in a wide range of situations including road and bridge construction, site development, land boundary confirmation work, as well as forest boundary checks and infrastructure inspections. Not only major construction companies but also small and medium contractors are increasingly testing it as part of site DX, and AR technology is starting to spread. As an administrative initiative, local governments have conducted pilot experiments using AR for sewer maintenance management or combining drone imagery with AR for forest boundary confirmation.

Q: I want to introduce new technology, but I’m worried about cost. A: Specialized AR display devices and high-performance positioning equipment used to be expensive, but today high-precision AR surveying can be achieved by combining smartphones with relatively affordable GNSS receivers. Compared with existing methods (for example, surveying with a total station), initial investment can often be kept lower. Solutions like the LRTK series package the necessary equipment and apps, allowing cost-effective introduction. You can also introduce AR technology gradually in some processes, leveraging existing equipment while progressing digitalization without undue burden.