Cloud × Tilt-Compensated GNSS for Site Efficiency: Easy High-Precision Positioning Realized by LRTK

Table of Contents

• What is tilt-compensated GNSS

• Why tilt compensation is required (site challenges)

• How the technology that achieves tilt compensation works

• Features of LRTK equipped with tilt-compensated GNSS

• Case studies and use cases of site work efficiency using LRTK

• Data sharing and measurement flexibility through cloud integration

• Compatibility and potential of tilt-compensated GNSS with cloud integration

• The overall picture of simple, high-precision positioning with LRTK

• Summary: Why we recommend introducing LRTK for surveying

• FAQ

What is tilt-compensated GNSS

Tilt-compensated GNSS is a technology that uses sensors built into surveying GNSS receivers to detect the tilt of the device and enables accurate positioning even when the pole (survey rod) is tilted. Normally, GNSS positioning requires the receiver (antenna) to be placed vertically directly above the survey point. Tilt-compensated GNSS relaxes this verticality constraint and can automatically correct the coordinates of the target point on the ground even when the receiver is tilted. For example, if the pole tip is kept on the point to be measured but the pole tilts, the device measures the tilt angle and orientation with internal sensors and corrects the position to the location it would have had if it had been ideally vertical.

Traditionally, surveyors adjusted the bubble level on the pole while repeatedly aligning the receiver directly overhead. With tilt-compensated GNSS, positioning errors are automatically corrected even when the pole cannot be kept perfectly vertical. As a result, surveying work is significantly sped up and positioning becomes easier even in narrow spaces or on unstable footing. In particular, recent advances in high-precision tilt detection using IMUs (inertial measurement units) have produced GNSS devices that can maintain accuracy within a few centimeters even at large tilts of around 30°–60°. Tilt-compensated GNSS can be said to be a new generation of GNSS technology developed to achieve both high-precision positioning and improved work efficiency.

Why tilt compensation is required (site challenges)

The demand for tilt-compensated GNSS stems from various challenges encountered on surveying sites. Traditional surveying required keeping GNSS receivers or prisms perfectly vertical, leading to the following problems.

• Narrow or obstacle-filled sites: At the edge of buildings or under trees, it was difficult to stand the pole vertically, making accurate positioning difficult. If there was no space to erect the pole or if it was on a slope where it could not be set from directly above, conventional practice often required abandoning the measurement or measuring by detouring.

• Increased workload and time: Adjusting the bubble level at each point to keep the pole vertical was time-consuming and placed a heavy burden on workers. Especially when measuring many points, repeatedly correcting posture increased the total time required for surveying.

• Manpower and communication: In traditional optical surveying (transit or total station), work was typically done by teams of two—a surveyor and an assistant. One person held the pole while the other recorded and gave directions, requiring coordination. Miscommunication could cause positional offsets or mistakes.

• Marking effort: In construction surveying, positions on design drawings were often first marked on the ground (layout) before construction. This multi-step process—surveying → marking → construction—was inefficient, and markings could shift or fade. A method that directly positions and measures was desired.

Because of these challenges, the field sought a technology that would allow surveying to be easier, doable by a single person, and reliable. In practice, reports show that the latest GNSS surveying methods have reduced work time to about one-sixth compared to traditional methods. Tilt-compensated GNSS attracted attention as a key technology that can solve these problems. If strict verticality of the pole is no longer necessary, one person can survey efficiently and reliably, improving overall surveying productivity.

How the technology that achieves tilt compensation works

So how does tilt-compensated GNSS detect tilt and correct for it? The core is sensor fusion technology using an IMU (inertial measurement unit). An IMU is a device combining accelerometers and gyroscopes that can rapidly measure three-dimensional motion (acceleration) and rotation (angular velocity). By embedding an IMU in the GNSS receiver and integrating its data with GNSS-derived position information, tilt compensation is achieved.

The basic mechanism is as follows.

• Tilt angle and heading measurement: The IMU inside the surveying device measures the receiver body’s tilt angles (pitch and roll) and heading (yaw) in real time. It captures, for example, how many degrees the pole is tilted and in which direction the tilt occurs on the millisecond scale.

• Calculating the pole tip position: From the GNSS antenna position (the coordinates in the tilted state), and using the tilt angles detected by the IMU and the pole length, the coordinates of the point where the pole tip contacts the ground are calculated. In other words, it triangulates how many centimeters the tip is offset downward and sideways from the receiver position.

• Sensor-fusion correction: GNSS positioning data and IMU tilt data are integrated to perform real-time correction to the point directly beneath the receiver. Crucial here is sensor fusion using advanced algorithms such as Kalman filters. By fusing GNSS’s absolute positioning with the IMU’s relative tilt detection, position estimation can be achieved with more stable accuracy than either sensor alone.

• Use of magnetic sensors (in some cases): Some models include a magnetic compass (geomagnetic sensor) in addition to the IMU to obtain an absolute heading reference. However, magnetic sensors are susceptible to errors from metal and surrounding environmental influences, so recent high-precision GNSS receivers often estimate heading using a gyro+accelerometer combination (self-calibration), simplifying magnetic calibration. Many modern devices achieve near “no-feel” calibration that completes automatically with just a little movement on first startup.

Through these processes, the receiver can always compute the accurate surveying point on the ground even when it is tilted. Importantly, IMU-based tilt compensation is highly effective over short periods and can yield results comparable to GNSS-only positioning accuracy. Sensor drift (accumulated error) is periodically reset or corrected by GNSS signals, so within typical surveying timeframes accuracy degradation is not a concern. Understanding these mechanisms helps explain why tilt-compensated GNSS is reliable.

Features of LRTK equipped with tilt-compensated GNSS

LRTK is a cloud-integrated, cutting-edge GNSS solution and, naturally, a positioning device equipped with this tilt-compensated GNSS functionality. The LRTK device is an ultra-compact RTK-GNSS receiver that attaches to a smartphone; despite its pocket size it has a built-in battery and weighs 125 g and is 13 mm (0.51 in) thick. It is designed for one-touch attachment/detachment to a dedicated smartphone case so you can instantly turn your smartphone into a high-precision positioning device when needed.

Main features of LRTK:

• Tilt-compensated easy positioning: It supports tilt compensation using an IMU, allowing automatic acquisition of the coordinates directly beneath the tip when the LRTK device is attached to a pole and the pole is somewhat tilted. Even in narrow locations where it is hard to stand a pole vertically, LRTK can maintain accuracy while positioning. For example, measurement points at the edge of a building or the position of a road manhole can be accurately recorded simply by tilting the pole and touching the tip to the point.

• Centimeter-level high-precision RTK: LRTK supports RTK positioning and can obtain absolute coordinates with errors of a few centimeters on site. In actual measurements, accuracies of about ±1〜2 cm (±0.4〜0.8 in) horizontally and about ±3 cm (±1.2 in) in elevation have been achieved, and using the averaging positioning function can improve accuracy to the order of a few millimeters per point. This level of precision is comparable to first-class GNSS equipment and is sufficient for full-scale surveying tasks.

• Smartphone-integrated convenience: Heavy tripods and controllers are unnecessary. By attaching to a smartphone and carrying it by hand, you can keep it in your pocket and quickly take it out for positioning when needed. Using an optional monopod (dedicated pole) enables more stable single-point positioning and stake-driving tasks. When using a pole, the height offset can be corrected with a single button in the app, allowing tip coordinates to be obtained without cumbersome calculations.

• Intuitive app operation: Install the dedicated LRTK app on your smartphone to clearly display current coordinates and target points on the screen. Positioning starts with one button, and acquired data is automatically organized and saved. In addition to latitude and longitude, Japan’s plane rectangular coordinate system and geoid heights (JGD2011 standard) are automatically calculated and displayed, and date/time and notes can be recorded for each point. Coordinate transformations that previously required specialist knowledge are all handled by the app behind the scenes, so anyone can use it without mistakes.

• Multi-frequency and offline support: The LRTK receiver supports multi-GNSS and multi-frequency and is compatible with the centimeter-class augmentation service (CLAS) provided by Japan’s quasi-zenith satellite “Michibiki.” Therefore, even in mountainous or disaster sites where mobile signals do not reach, Michibiki correction signals can be received directly for high-precision positioning. Positioning can continue even where internet-based base station corrections (VRS/Ntrip, etc.) are not available, increasing reliability in emergencies.

Thus, LRTK is an innovative device that maximizes the advantages of tilt-compensated GNSS while balancing portability and high precision. Its smartphone integration improves usability, enabling one-stop handling from positioning and measurement to data utilization.

Case studies and use cases of site work efficiency using LRTK

How does site work actually become more efficient when LRTK is introduced? Here are some concrete on-site use cases.

• Each worker instantly becomes a surveyor: Situations that used to require calling a specialist or preparing heavy equipment can be handled by the worker on site with LRTK. For example, on road construction sites supervisors and craftsmen can each carry an iPhone + LRTK and measure and record coordinates at required points on the spot. With each person carrying a high-precision positioning tool, losses from waiting for personnel and setup time can be drastically reduced.

• Speeding up stake-driving: For locating piles for bridge piers or building foundations, smartphone surveying plus tilt-compensated GNSS can eliminate intermediate layout steps. With pile design coordinates pre-shared in the cloud, workers can call them up in the app and reach the exact location by following on-screen guidance. Even without expensive GNSS equipment on heavy machinery, the worker’s smartphone screen will show “this is the pile position,” so anyone can place piles without confusion. In one site, this method simplified the pile positioning process so that the same level of accuracy could be achieved even in the absence of experienced surveyors.

• Surveying in narrow or hazardous locations: Tilt compensation enables measurement of points that were previously abandoned. For example, at cliff edges, alongside retaining walls, or across waterways where footing is poor and the device cannot be placed directly overhead, a worker can insert the pole at an angle and touch the tip to take safe and accurate coordinates. This improves survey coverage and reduces missed measurements and unsafe postures.

• Rapid situational assessment at disaster sites: LRTK’s lightweight compactness offers mobility for emergency deployment. Even where large equipment cannot be brought in, a single LRTK unit can measure and record disaster site conditions and instantly share them via the cloud. In a disaster area out of mobile service, LRTK used Michibiki’s CLAS signals to achieve high-precision offline positioning and quickly relay site information to stakeholders. LRTK enables rapid data collection and sharing even in situations where surveying was previously impractical.

• Point cloud scanning and as-built management: LRTK can be used not only for single-point surveying but also for acquiring high-precision 3D point cloud data in combination with smartphone cameras or LiDAR. For example, to calculate excavated volume on-site, a worker can walk around photographing the surroundings with a smartphone to generate a georeferenced point cloud model. As-built management that used to be outsourced can now be done in-house in a short time, dramatically shortening the construction management PDCA cycle.

As shown above, the efficiency benefits of LRTK in the field are diverse. It not only reduces effort in positioning but also provides total efficiency gains including subsequent data processing and sharing. Site feedback includes comments such as “we can’t go back to working without LRTK” and “I always keep it in my pocket and discover new uses depending on ideas,” indicating high operational freedom in the field.

Data sharing and measurement flexibility through cloud integration

One of LRTK’s major strengths is data sharing and workflow flexibility enabled by integration with cloud services. With traditional surveying equipment, data collected on site had to be brought back via USB or memory card and imported into a PC and CAD software, which was time-consuming. LRTK greatly simplifies these processes.

After positioning is completed on site, data can be uploaded to the “LRTK Cloud” with one tap from the smartphone app. Uploaded survey point information can be instantly shared over the internet with office colleagues or clients. For example, newly measured coordinates or point clouds are plotted on a cloud-based map, and stakeholders can view them immediately in a browser without logging in. Measurements such as distances or areas between points can be performed in the cloud, eliminating the need to perform calculations after returning from the field.

Also, the cloud-based data sharing function makes it easy to provide information to subcontractors or clients. You can select data to be shared on LRTK Cloud and issue a shareable URL with one click. By giving the URL and a set password, recipients can view and download data via LRTK Cloud’s web interface. Supported formats include business-friendly formats like CSV and SIMA, allowing direct import into CAD or GIS. This eliminates cumbersome exchanges such as email attachments or handing over paper drawings and ensures everyone in the project can always reference the latest data.

Cloud integration goes beyond simple sharing. Real-time circulation of data between the field and the office creates new flexibility. For instance, if design coordinates created during the design phase are registered in the cloud, field workers can call them up on a smartphone for on-site guidance (as in the pile-driving guidance case). Conversely, uploading as-built data from the field to the cloud can automatically generate orthophotos or contour maps for immediate sharing with the office—advanced processing that previously required expensive software and high-performance PCs. By leveraging cloud computing resources, such advanced measurement and analysis can be performed without burdening the device.

In short, LRTK and cloud integration enable a workflow where “measure on site and instantly share with everyone” and “perform necessary measurements anytime, anywhere.” This is highly beneficial from the perspective of work-style reform, reducing information transmission loss between the field and office and dramatically improving the flexibility of surveying and measurement work.

Compatibility and potential of tilt-compensated GNSS with cloud integration

The two keywords—tilt-compensated GNSS and cloud integration—are an excellent combination for on-site DX (digital transformation). Each is useful on its own, but together they create the following synergistic effects and possibilities.

• Real-time progress sharing: By quickly acquiring many positioning points with tilt-compensated GNSS and sharing them via the cloud in real time, the entire team can instantly grasp site progress. For example, measuring daily fill volumes on an earthwork project with tilt-compensated GNSS-equipped devices and uploading to the cloud allows the remote office to confirm as-built conditions on the same day, minimizing time lag between field and office.

• Centralized data management and utilization: Accumulated survey data in the cloud can be integrated and managed with the project’s GIS map or BIM model. Overlaying precise point clouds and coordinate information obtained by tilt-compensated GNSS in the cloud makes it easy for stakeholders to align their understanding. Online comparisons with design drawings and construction plans help detect rework or errors early. In the future, accumulated data could be AI-analyzed to optimize construction processes or monitor terrain changes.

• Fusion with new surveying methods: Tilt-compensated GNSS + cloud makes combining with other technologies easier. For example, integration with AR (augmented reality): calling up cloud-based design data on a smartphone and overlaying it on the real scene creates intuitive AR guides to support on-site work. Since tilt compensation ensures accurate positioning even with a tilted pole, AR overlays remain aligned with the real world. This enables construction support that non-experts can understand intuitively.

• Expansion into machine guidance: While large sites often equip heavy machinery with GNSS, similar capabilities can be realized on small- to medium-scale sites with smartphone + LRTK. Cloud-synced tablets carried by workers can display the operator’s position and design lines, enabling guided construction. Reference points obtained with tilt-compensated GNSS can be shared in the cloud and referenced by machinery, enabling flexible on-site IoT integration. The ability to achieve machine-guidance-like construction precision with inexpensive equipment could broaden adoption across the construction industry.

Thus, tilt-compensated GNSS and cloud integration amplify each other’s strengths. The Japanese government’s initiatives like “i-Construction” and “ICT construction” emphasize GNSS and cloud utilization. In that context, integrated systems like LRTK that include tilt-compensated GNSS are solutions well matched to current needs and will likely see expanding applications.

The overall picture of simple, high-precision positioning with LRTK

As described so far, LRTK fuses tilt-compensated GNSS technology with the cloud to provide a total package for simple and high-precision positioning. The overall solution consists of the following elements.

• Hardware: A smartphone-mounted compact RTK-GNSS receiver (LRTK device). This handles tilt-compensation-enabled high-precision GNSS positioning. It is portable, can be mounted on a pole or monopod as needed, runs for long periods on an internal battery, and enables agile surveying anywhere.

• Software (smartphone app): A dedicated app for iPhone/iPad processes position data received from the device in real time. It provides intuitive UI controls for starting/stopping positioning, saving points, toggling averaging and continuous modes, photo capture with position recording, AR guidance, and more. The app seamlessly connects to the cloud for one-tap data sync and sharing.

• Cloud service: On LRTK Cloud, uploaded survey data is organized and stored per project. You can view survey points on a map, recreate the site using a 3D point cloud viewer, and automatically generate deliverables (plans, cross-sections, volume reports, etc.) from measurement data. URL sharing facilitates smooth external data provision. The cloud is not just storage but a place to immediately turn field data into valuable information.

• Workflow integration: By combining the above hardware, software, and cloud, the formerly segmented workflow of surveying → data processing → sharing → utilization becomes continuous. For example, share baseline coordinates obtained by LRTK at the start of the day via the cloud, aggregate measurement data collected throughout the day, and in the evening compile as-built checks and reports—creating a seamless daily data cycle. No paper field books or USBs are needed; the field and office are constantly connected by data, which is the essence of LRTK’s simple positioning.

From this perspective, LRTK is not merely a replacement for surveying equipment but a solution that transforms the surveying workflow itself. When high-precision positioning becomes available to everyone, field DX accelerates and tasks previously delegated to specialists or later processes can be handled in real time in-house. In short, LRTK’s simple, high-precision positioning optimizes the entire process—from measuring to immediately utilizing measured data—transforming on-site operations.

Summary: Why we recommend introducing LRTK for surveying

Finally, here is a summary of why we strongly recommend introducing LRTK.

LRTK combines the work-efficiency and high-precision benefits of tilt-compensated GNSS with the data-utilization power of cloud integration to bring new value to surveying and construction sites. Survey tasks that used to take two people and much time can now be completed quickly by one person using LRTK, and the data obtained is immediately shared on the cloud for team-wide real-time use.

LRTK’s intuitive smartphone app enables advanced positioning by non-specialists, addressing workforce shortages in the construction industry and allowing anyone to maintain accuracy in site operations. Its compact, lightweight, and cost-effective configuration makes it accessible to small- and medium-sized sites and local governments that previously avoided expensive equipment. The ability to adopt surveying DX while keeping initial and maintenance costs down is a major attraction.

Future-proofing and expandability are also notable. LRTK will continue to receive updates to expand functionality, and features such as AR construction support, photo records, and indoor positioning mode are already implemented. LRTK is more than a surveying instrument; it is a platform that continues to evolve. Once introduced, you don’t stop at that point—you can continuously enjoy the latest features.

In summary, introducing LRTK’s simple surveying can improve “efficiency,” “accuracy,” and “sharing” all at once. LRTK enhances site productivity and safety and enables data-driven construction management for everyone. It will become a standard on-site tool going forward. We encourage surveyors, construction managers, infrastructure inspectors, and municipal staff to experience this new positioning solution. We hope LRTK’s adoption will propel your sites to the next stage.

FAQ

Q: Can you really position accurately while keeping the pole tilted? A: Yes. The latest tilt-compensated GNSS devices including LRTK can maintain high precision at the centimeter level even when the pole is somewhat tilted. Built-in IMU sensors detect tilt angles and orientation and correct positioning data in real time. However, extreme angles or large movements may degrade accuracy, so using a monopod or combining short-term averaging positioning functions as needed is recommended to ensure precision.

Q: Can people without surveying expertise operate LRTK? A: Yes. LRTK is designed to be user-friendly for beginners. The dedicated smartphone app clearly displays current location and target points and is operated intuitively with buttons. Coordinate system settings and calculations are automated, so non-experts can obtain accurate results. There are cases where untrained workers used LRTK to place piles correctly without problems.

Q: How can data measured on site be shared? A: Data acquired with LRTK can be uploaded to the cloud from the smartphone on site. Data stored in the cloud can be shared instantly over the internet with office PCs and other team members. Using the cloud’s sharing features, you can send a one-click generated URL to stakeholders so they can view and download data. This eliminates cumbersome file exchanges and reporting and ensures everyone can always access the latest data.

Q: Can LRTK be used in mountainous areas or indoors where there is no mobile signal? A: High-precision positioning is possible even in mountainous areas without mobile coverage. The LRTK receiver can receive CLAS correction signals from Japan’s quasi-zenith satellite Michibiki, so it can obtain correction information directly from satellites and maintain centimeter-level accuracy without internet connectivity. However, satellite visibility (open sky) is required. In places where GNSS signals cannot reach, such as indoors or underground, an “indoor positioning” mode allows you to obtain a reference position outdoors once and then continue short-term positioning using IMU-based dead reckoning.

Q: If we introduce LRTK, will conventional surveying equipment become unnecessary? A: In many cases, LRTK alone can cover everyday surveying and measurement needs, from reference point surveys to as-built management and pile-driving guidance. However, for ultra-long-distance precision traverses or cases requiring special accuracy management, conventional total stations may still be suitable. LRTK can serve as the main tool for field surveying, but combining it with existing equipment and using each where appropriate will create a more efficient and robust surveying system.