Coordinate navigation revolutionizes pile driving! Easy 3D construction made possible by LRTK

Introduction: the current state of 3D construction and pile-driving work

In recent years, the construction industry has been paying attention to a method called 3D construction, which uses three-dimensional data in construction processes. By using digital 3D models and coordinate data from the design stage and referring to them directly on site, the aim is to improve productivity and accuracy. In reality, however, in many sites basic layout tasks such as pile driving (kuiuchi) operations still rely on traditional methods.

In typical pile-driving work, surveyors or site personnel determine the positions where “a pile should be driven” based on 2D drawings and mark them by placing stakes or markers on the ground. The typical method uses a total station (optical survey instrument): the instrument is set up, and angles and distances are measured from reference points to determine each pile position. This work usually requires two or more people, and placing many piles over a large site entails significant labor and time. Operating surveying instruments also requires specialized knowledge and experience, and with a shortage of skilled workers and general labor shortages becoming more severe, pile-driving work can become a bottleneck.

Moreover, outdoor work can be hindered by bad weather or terrain that makes instrument setup difficult or prevents line-of-sight, delaying layout. Manual layout inherently carries measurement errors and marking mistakes, and even a few centimeters’ deviation in pile position can affect later construction quality. Therefore, traditional pile driving required experienced staff to proceed carefully with repeated checks. Even with the concept of 3D construction, there were practical limits to efficiency at the actual pile-driving stage.

What is coordinate navigation? Definition and functions

The approach that has emerged as a key to changing this situation is the new concept called "coordinate navigation". As the name suggests, coordinate navigation refers to technologies or functions that guide a person or machine to a specific coordinate point. If the target point’s coordinate values (latitude, longitude, height, etc.) are known in advance, workers can be navigated to that location using GNSS (Global Navigation Satellite Systems) and similar technologies. To put it simply, it is like an on-site car navigation system. Just as a car GPS guides a driver to a destination address, coordinate navigation guides a worker directly to a set target coordinate.

The basic mechanism of coordinate navigation is simple. When the target coordinates are entered (or selected) into a device, the device displays the direction to proceed and the remaining distance in real time. The worker simply walks in the direction indicated by the on-screen arrow and can instantly tell whether they are getting closer or farther from the target. When far away, the device shows the “approximate direction and distance”; as you approach it gives “more precise distance and direction” guidance, and finally indicates the arrival point clearly, like “this is the target point!”

This idea of coordinate guidance is very powerful if accuracy can be ensured. Without staring at survey drawings or tape measures, anyone can reach the correct point using intuitive navigation. However, realization required positioning technology capable of centimeter-level accuracy. That led to the development of the high-precision positioning solution using smartphones called "LRTK". LRTK equips a smartphone with a compact RTK-GNSS receiver to enable centimeter-level positioning and provides an all-in-one field tool offering various functions on an app, including coordinate navigation. In the next section we will look concretely at the flow and features of coordinate guidance using LRTK.

Flow and features of coordinate guidance with LRTK

Using LRTK’s coordinate navigation feature makes guidance to pile-driving positions remarkably easy. The actual usage flow is explained step by step below.

• Preparation of coordinate data: Before construction, the design coordinate list of points where piles or installations are required is registered in LRTK’s cloud system. Each point can be managed with a name or ID, allowing hundreds of coordinates to be organized even on large sites. On site, the target coordinate becomes the navigation target simply by selecting the desired point from the LRTK app on a smartphone.

• Start navigation: Once the target coordinates are set, an direction arrow and the straight-line distance to the target are displayed on the smartphone screen, and guidance begins. For example, the screen may display “Northeast 5.3 m (17.4 ft)”, so you proceed in that northeast direction. Because LRTK continuously updates your position using high-precision GNSS positioning, the distance reading decreases as you walk and the direction is corrected continuously.

• Precision guidance and arrival confirmation: As you approach the target, the display automatically switches to a more precise guidance mode. It guides you until the remaining tiny error becomes zero, with indications like “20 cm (7.9 in) remaining” or “10 cm (3.9 in) remaining.” When you finally coincide with the target point, the on-screen marker aligns exactly and the app notifies you of arrival with sound or visuals. This completes guidance to the specified coordinates. You then drive the pile or mark the spot, and the layout task is finished.

As this flow shows, LRTK’s coordinate guidance can be completed with button operations and on-screen instructions even without specialist knowledge. There is no need to remeasure dimensions on site or set up an instrument and swing angles. A single worker holding a smartphone can walk to the exact intended point.

A notable feature of LRTK coordinate navigation is the combination of high precision and ease of use. RTK-GNSS positioning keeps horizontal errors to several cm (several in) and vertical errors also to several cm (several in), enabling point identification with accuracy comparable to a total station. At the same time, the operation is intuitive—just follow the visual arrow guidance on the screen—so even first-time users will not be confused. The fact that the equipment is portable by one person is also important. LRTK operates with a smartphone and a palm-sized receiver, so heavy tripods and large instruments are unnecessary. It imposes little burden when walking around a site, requires no setup time, and can continuously position and guide many points across a wide area without breaks.

Furthermore, the LRTK app’s use of camera AR display as an auxiliary function during guidance is also innovative. As described later, in short, when you hold up your smartphone near the target point, a “virtual pile (AR marker)” appears on the camera image, indicating the spot as if a pile already stood there. If your position and the virtual pile coincide on the screen, it proves you are standing at the designed point. This kind of visual feedback increases confidence in pile-driving work.

Comparison with traditional pile driving and problem solving

Coordinate-navigation-based pile driving resolves many issues of traditional methods at once. Below we summarize the advantages by comparing with conventional approaches.

• Required personnel and skills: Traditionally, a pair of a staff member skilled in operating survey instruments and an assistant was needed, and it took time to become proficient. With LRTK, one person can operate it, and special qualifications or many years of experience are not required. Even sites struggling with a shortage of skilled workers can complete pile-layout processes with fewer people.

• Work speed: With total stations, time was taken for instrument setup/cleanup and angle setup for each point. On large sites, relocating the instrument often required re-surveying. Coordinate navigation allows you to move to successive new targets on the spot, so time per survey point is greatly reduced. For example, a pile-driving task that used to take half a day for ten points might be completed in just 1–2 hours using LRTK in some cases.

• Accuracy and reliability: Manual surveying carried the risk of human error, such as misreading or marking offsets. Coordinate navigation provides guidance based on digital data, so points are always indicated according to the design values. During work, the current error is displayed in real time, so deviations are immediately noticed and corrected. As a result, variation in positional accuracy is reduced and quality assurance is improved.

• Reinstallation and rework: On site, driven pile markers are sometimes removed or moved by heavy equipment. Traditionally, this required calling the surveying team back for restoration, but with coordinate navigation, anyone can quickly restore a point at any time. As long as the design coordinates remain, even missing points can be immediately shown on site, minimizing rework.

• Cost and adoption barriers: Robotic total stations with automatic tracking or high-precision GNSS devices can enable single-operator workflows, but these are very expensive and often out of reach for small and medium enterprises. They also require device-specific software operation and maintenance. In contrast, LRTK’s smartphone and compact device approach lowers initial cost, and usage can be learned like a smartphone app. It provides a practical solution for sites that previously gave up on 3D construction because of cost or technical difficulties.

As described above, the combination of coordinate navigation and LRTK fundamentally eliminates inefficient aspects of the past. The need to haul surveying equipment, worry about weather, or struggle with staffing is greatly reduced, enabling high-accuracy pile driving with fewer people in a shorter time. This represents a major step toward broader adoption of 3D construction.

Use cases: effects of coordinate navigation on site

Sites that have actually introduced coordinate navigation report various beneficial effects on work efficiency and quality. Here are some concrete examples.

• Pile driving for large-scale solar power plants: In mega-solar construction, where hundreds of piles must be driven over vast areas, LRTK’s coordinate navigation has proven powerful. Previously, surveying teams set batter boards from reference points and operators aligned positions with hand signals as piles were driven, but after introducing LRTK, site supervisors could single-handedly direct successive pile positions. With on-screen markers and AR piles, operators could guide heavy machinery to exact positions without confusion. As a result, the entire pile-driving phase’s duration was dramatically shortened—in some cases, the work time was reduced to less than half compared to before. Also, because actual coordinates of each pile can be measured and recorded on the spot, inspectors could immediately confirm whether placements were within a few centimeters (a few inches) of the design values, and any deviations could be corrected before racking installation, preventing problems later.

• Reproducing survey points at disaster recovery sites: In landslide-affected areas, it is necessary to repeatedly record conditions from exactly the same points. In one municipality’s case, LRTK was used to save coordinates and orientation from the first survey, and months later the coordinate navigation function was used for follow-up surveys. As a result, even different personnel could reach the same positions as before without difficulty and take photographs from the same angle. This enabled accurate comparison of survey data, helped track recovery progress, and centralized management of field notes and photos via the cloud, improving operational efficiency.

• Confirming boundary points of land parcels: In mountainous development sites where boundary stakes are often lost under trees or grass, LRTK has been used to confirm land boundary points. By importing boundary coordinates from cadastral maps and navigating to those coordinates on site, workers could pinpoint boundary stakes even in dense undergrowth. Workers commented that “it’s faster than searching with a metal detector” and “we no longer waste time on wrong assumptions in large forests.” Even reference points hidden by vegetation or snow can be found by digging where coordinate navigation indicates, dramatically improving inspection reliability.

As these cases show, coordinate-navigation-based pile driving and surveying bring both productivity gains and quality assurance to sites. Shorter work times reduce labor costs and schedules, while improved accuracy reduces rework and defects in subsequent processes, contributing to overall project cost reductions and increased reliability. Because all data are digitally recorded and shared, stakeholder communication is smoother: construction managers can check positioning results and photos in the cloud from the office and make real-time decisions and instructions. Coordinate navigation + LRTK thus positively affects not only pile-driving tasks but also on-site communication and management.

Innovation through combination with AR display

Combining coordinate navigation with AR (augmented reality) display further enhances convenience and transforms the on-site experience. LRTK leverages high-precision position information to overlay 3D models and markers on the smartphone camera view without misalignment relative to the real world. This function makes the “design completion image” or “invisible reference point” that used to exist only in one’s head visible directly on site.

For example, the LRTK app can AR-project registered design drawings or model data on the spot. Displaying a building or structure’s completion model on the ground lets all site staff intuitively share the finished appearance and facilitates on-the-spot decisions. In civil engineering, it is possible to project plan lines (such as road centerlines or finished surface elevations) onto the ground and compare them with the current ground or earthwork conditions. Information like “the road edge will be here” or “fill is needed up to this height” becomes visually apparent at a glance.

Particularly useful for pile driving is the previously mentioned AR pile marker display. When you look around through your smartphone near the target coordinate, a virtual colorful pile appears to stand on the actual ground. Even in dark conditions or on vacant lots without markers, the screen clearly indicates “drive a pile here!”, eliminating missed markings. On steep slopes or in hazardous areas where approaching is dangerous, you can confirm positions without close approach by standing safely at a distance and using AR to view the target direction. By combining these AR uses, workers can verify the site by overlaying digital information on the real scene rather than relying solely on instrument values. This fusion of intuition and data is truly transformative for construction sites.

Looking ahead, possibilities expand further with AR technology. For example, if LRTK guidance could be experienced hands-free on smart glasses, directional arrows and models would appear in the worker’s field of view during operations, which would be useful when both hands are occupied. While the smartphone screen is already practical, AR glasses for pile-driving navigation are becoming realistic in the near future. As 3D construction × AR advances, the gap between drawings and the site will shrink and the entire construction process will become more seamlessly integrated.

Benefits of adoption for small teams and SMEs

LRTK-based coordinate navigation offers especially large benefits for small teams and small-to-medium enterprises rather than just major firms. Here are the advantages for sites constrained by personnel and budget.

First, the low initial investment barrier is attractive. Traditional ICT construction equipment is expensive and required dedicated operator training, making it hard for small companies to adopt. LRTK, by contrast, consists of a smartphone, a compact receiver, and a service contract, and can be put into operation as soon as the essentials are in place. Pricing is lower than existing surveying instruments, so cost-effectively adopting cutting-edge technology appeals to small and medium-sized contractors.

Second, the ease of use for anyone is a big help to teams operating with limited personnel. Even without a veteran surveyor, site supervisors or workers can perform surveying and pile layout in spare time. Handling tasks in-house that were previously outsourced because they were “outside our expertise” leads to cost savings and shorter lead times. Sites that have introduced LRTK report that “the time spent on surveying has been greatly reduced, allowing staff to be allocated to other important tasks” and “we no longer have to worry so much about controlling pile position accuracy, giving us more leeway in construction planning.” In small teams, improving each person’s productivity has a large impact on the whole project, and LRTK becomes a powerful helper.

Also noteworthy is that multiple functions are consolidated into one device. In addition to coordinate navigation, LRTK offers single-point surveying (recording point positions), automatic coordinate tagging of photos, point cloud acquisition via 3D scanning, as-built data checks, and cloud-based team sharing. Covering all these functions with separate equipment and software would require a large investment and complex operations, but with LRTK it can be done with one smartphone. Even resource-constrained SMEs can implement advanced construction management comparable to large companies by using LRTK. This contributes to raising the industry baseline and distributes the benefits of digital technology widely.

Future prospects and industry impact

The pile-driving revolution enabled by coordinate navigation is only just beginning, but it points to a broader transformation in the construction industry. Looking ahead, first we can expect further diffusion of digital surveying and construction technologies. Initiatives like the Ministry of Land, Infrastructure, Transport and Tourism’s i-Construction provide tailwinds, and if easy-to-use, high-precision tools like LRTK become widespread on sites, the industry’s DX (digital transformation) will accelerate. In the future, all site data including construction records may be digitally managed and shared, and the scene of “paper pile-driving drawings being cross-checked on site” may become a thing of the past.

We can also expect the establishment of new construction styles centered on LRTK. For example, integration with automated heavy equipment control. Although 3D machine guidance and machine control are already being implemented in some places, LRTK could serve as a high-precision location information hub, making it more feasible for machines to autonomously move to designated positions and perform excavation or installation. Combining drone-based wide-area 3D survey data to enable real-time feedback from planning through as-built inspection could make smart construction commonplace, shortening schedules, improving quality, and reducing previously unseen waste and risks.

There will also be impacts on the workforce. The era requiring artisan-level skill for surveying and staking may shift toward one where a digital-savvy generation using tablets and smartphones takes the lead. If young workers see construction as a tech-enabled workplace, it will help alleviate labor shortages and promote technology transfer. By having technology complement and substitute parts of veteran intuition and experience, safety and error reduction will improve—a significant advantage. In short, the pile-driving revolution brought by coordinate navigation has the potential to change the industry not as a point but as a line, reshaping the entire sector.

With this outlook, next-generation surveying and construction methods unconstrained by traditional assumptions are expected to dramatically improve on-site productivity and reliability, contributing to the advancement of the construction industry. New technologies like LRTK will increasingly be key to achieving the balance of “accuracy × efficiency.”

Conclusion and a natural lead-in to easy surveying with LRTK

This article explained the revolutionary progress of pile-driving work through coordinate navigation in the context of 3D construction and the LRTK functions that make it possible. The era is approaching in which pile-positioning that once relied on manpower and experience can be performed quickly and accurately by anyone thanks to LRTK. By achieving centimeter-level accuracy and intuitive AR guidance with a familiar tool such as a smartphone, LRTK can be called a game changer for construction sites.

If you, as a construction manager, feel issues with traditional methods and worry “can we really use this ourselves?”, there is no need for undue concern. LRTK is designed with simple equipment composition and easy-to-understand operation, so it can be used on site without special qualifications or advanced training. It is a good idea to try it on a small-scale project or limited application first to experience its convenience and effectiveness. The experience that “with just a smartphone you can achieve pro-level surveying through simple procedures” will surely change site norms.

Construction that combines accuracy and speed is a source of competitiveness for any project. If you feel any inefficiency or unease in your surveying or pile-driving processes, consider LRTK’s easy surveying features. By adopting the latest technology, everyone can easily realize 3D construction and achieve both higher productivity and quality on site—an era that is now within reach.