Table of Contents

• What is tilt-compensated GNSS

• Why tilt compensation is needed (field challenges)

• How the technology that enables tilt compensation works

• Features of LRTK equipped with tilt-compensated GNSS

• Examples and use cases of field efficiency with 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

• Conclusion: Why we recommend adopting LRTK for surveying

• FAQ

What is tilt-compensated GNSS

Tilt-compensated GNSS is a technology in which sensors built into a surveying GNSS receiver detect the device's tilt and enable 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 automatically corrects 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 leans, the device measures the tilt angle and direction with internal sensors and corrects the position to where it would be if it were ideally vertical.

Traditionally, surveyors adjusted the pole bubble (spirit level) during measurement to keep the pole vertical and repeatedly repositioned the receiver until it was 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 becomes markedly faster and positioning becomes easier in narrow or difficult-to-access locations. In particular, advances in high-precision tilt detection using IMUs (inertial measurement units) have produced GNSS devices that can maintain accuracy within a few centimeters even for large tilts of about 30°–60°. Tilt-compensated GNSS can thus be regarded as a new generation of GNSS technology developed to combine high-precision positioning with improved work efficiency.

Why tilt compensation is needed (field challenges)

The demand for tilt-compensated GNSS stems from various challenges encountered at surveying sites. In traditional surveying, GNSS receivers and prisms must be kept vertical at all times, which caused the following problems.

• Sites with limited space or many obstructions: In places such as next to buildings or under trees where it is difficult to stand a pole vertically, accurate positioning was challenging. When there was no space to erect a pole or when a vertical overhead placement was impossible on a slope, conventional practice required either abandoning the measurement or measuring by detour.

• Increased workload and time: Adjusting the bubble on the level to keep the pole vertical at each point was time-consuming and physically demanding. Especially when measuring many points, repeatedly correcting posture increased the total surveying time.

• Manpower and communication: In traditional optical surveying (transit or total station), it was common for a surveyor and an assistant to work as a pair. One person held the pole while the other read and gave instructions, necessitating coordinated effort. Miscommunication could cause positional errors or mistakes.

• Marking effort: In construction surveying, it was necessary to first mark positions from the design drawings onto the ground (staking), then proceed with construction. This staged process—survey→mark→construct—was inefficient, and markings could shift or disappear. A method to locate and position directly was desired.

Because of these issues, there was demand for technology that would allow surveying to be done “more easily,” “by a single person,” and “reliably.” In fact, some reports indicate that modern GNSS surveying has reduced work time to about 1/6 compared to conventional methods. Tilt-compensated GNSS has attracted attention as a key technology capable of solving these problems. If strict attention to pole verticality is no longer required, one person can perform measurements efficiently and reliably, improving overall surveying productivity.

How the technology that enables tilt compensation works

How does tilt-compensated GNSS detect and correct tilt? The core is sensor fusion technology using an IMU (inertial measurement unit). An IMU combines accelerometers and gyroscopes, enabling high-speed measurement of three-dimensional motion (acceleration) and rotation (angular velocity). By integrating an IMU into a GNSS receiver and combining its data with GNSS position information, tilt compensation is achieved.

The basic mechanism is as follows.

• Measurement of tilt angles and heading: The IMU inside the surveying device measures the receiver body’s tilt angles (pitch and roll) and orientation (yaw) in real time. For example, it captures how many degrees the pole is tilted and in which direction in milliseconds.

• Calculation of the pole tip position: From the GNSS antenna position (the coordinates while tilted), 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 below and to the side the pole tip is offset 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 absolute positioning with IMU relative tilt detection, position estimates become more stable and accurate than either sensor alone.

• Use of magnetic sensors (in some cases): Some models include a magnetic compass (geomagnetic sensor) within the IMU to obtain an absolute heading reference. However, magnetic sensors are susceptible to errors from nearby metal and environmental influences, so recent high-precision GNSS receivers often estimate heading from a gyroscope-plus-accelerometer combination (self-calibration), simplifying magnetic calibration. Many modern devices achieve a calibration close to “mukan”—where a little movement at initial startup is enough to complete automatic calibration.

Through these processes, the receiver can always compute the correct ground positioning point even when tilted. Importantly, IMU-based tilt compensation is highly effective for short durations and can yield results comparable to GNSS-only positioning. Sensor drift is periodically reset and corrected by GNSS signals, so within typical surveying operation times there is no need to worry about degradation of accuracy. Understanding this mechanism makes it clear why tilt-compensated GNSS can be trusted.

Features of LRTK equipped with tilt-compensated GNSS

LRTK is a cloud-integrated, modern GNSS solution and naturally a positioning device equipped with tilt-compensated GNSS functionality. The LRTK device is an ultra-compact RTK-GNSS receiver that attaches to a smartphone; despite its pocketable size—125 g weight and 13 mm thickness—it includes a battery. It is designed to snap on and off a dedicated smartphone case, allowing you to turn a phone into a high-precision positioning device whenever needed.

Main features of LRTK:

• Easy positioning with tilt compensation: It supports tilt compensation using an IMU, so when the LRTK device is mounted on a pole tip for surveying, moderate tilt is automatically corrected to obtain the coordinates directly beneath the tip. Even in narrow spots where it is hard to stand a pole vertically, LRTK can maintain accuracy. For example, you can accurately record coordinates of survey points next to buildings or the positions of road manholes simply by tilting the pole and placing the tip on the target.

• Centimeter-level high-precision RTK: LRTK supports RTK-based positioning and can obtain absolute coordinates with errors of a few centimeters on site. Field measurements show horizontal accuracy of about ±1–2 cm and vertical accuracy of about ±3 cm, and using averaging functions can further improve accuracy to a few millimeters per point. This is comparable to survey-grade GNSS equipment and is adequate for professional surveying tasks.

• Smartphone-integrated convenience: Heavy tripods and dedicated controllers are not required. The device attaches to a smartphone and can be carried in one hand, ready in your pocket to quickly convert your phone into a positioning tool when needed. With an optional monopod (dedicated pole), it supports more stable single-point measurements and stake-out 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 complicated calculations.

• Intuitive app operation: Installing the dedicated LRTK app on your smartphone clearly displays current coordinates and target points on the screen. Positioning starts with a single button and acquired data is automatically organized and saved. The app automatically calculates and displays not only latitude and longitude but also Japan’s plane rectangular coordinate system and geoid height (JGD2011 standard), and it records date/time and notes for each point. Coordinate transformations that previously required expert knowledge are handled by the app in the background, so anyone can operate it without making mistakes.

• Multi-frequency and offline support: The LRTK receiver supports multi-GNSS and multi-frequency and is compatible with the centimeter-level augmentation service (CLAS) provided by Japan’s quasi-zenith satellite “Michibiki” (QZSS). Therefore, even in mountainous areas or disaster sites without mobile reception, high-precision positioning is possible by receiving CLAS signals directly from Michibiki. Positioning can continue where internet-based base station corrections (VRS/Ntrip, etc.) are unavailable, increasing reliability in emergencies.

In this way, LRTK is an innovative device that maximizes the advantages of tilt-compensated GNSS while combining portability and high precision. Integrating with a smartphone improves usability, enabling one-stop workflows from positioning and measurement to data utilization.

Examples and use cases of field efficiency with LRTK

What specific efficiencies does LRTK bring to field work once introduced? Below are some concrete on-site use cases.

• Every worker becomes a surveyor on the spot: Tasks that previously required calling a surveying specialist or preparing heavy equipment can be handled immediately by workers with LRTK. For example, on road construction sites, supervisors and craftsmen can carry an iPhone + LRTK and measure and record coordinates at required points on the spot. With a high-precision positioning tool per person, losses from waiting for personnel and setup time are dramatically reduced.

• Faster stake-out work: For stake locations of bridge piers or building foundations, smartphone surveying with tilt-compensated GNSS can eliminate intermediate marking steps. Design coordinates for stakes shared in advance to the cloud can be pulled up in the app, and by following on-screen guidance you can reach the exact stake location simply by walking to it. You don’t need expensive GNSS equipment on heavy machinery; the worker’s phone screen will show “this is the stake location,” so anyone can place stakes without confusion. On one site, this method simplified stake-out procedures so that even without an experienced surveyor on site, stake installation achieved equivalent accuracy.

• Surveying in narrow or hazardous areas: Tilt compensation enables measurement of points that were previously impracticable. For instance, at cliff edges, next to retaining walls, or across channels where footing is poor and an overhead placement isn’t possible, you can insert the pole at an angle and touch the tip to measure, obtaining coordinates safely and accurately. This improves on-site survey coverage and reduces missed measurements and dangerous postures.

• Rapid situational awareness on disaster sites: LRTK’s light and compact form factor makes it highly deployable in emergencies. In major earthquake zones where bringing in large equipment is impossible, a single LRTK unit can measure and record conditions and share them via the cloud immediately. There have been cases where, even in areas without mobile reception, LRTK used Michibiki’s CLAS to achieve high-precision offline positioning and quickly convey local conditions to stakeholders. In situations where traditional surveying was unfeasible, LRTK enables rapid data collection and sharing.

• Point cloud scanning and as-built management: LRTK is useful not only for single-point surveys but also for obtaining high-precision 3D point cloud data when combined with a smartphone camera or LiDAR. For example, to calculate excavation volumes on-site, you can walk around while capturing images with the smartphone to generate a geo-referenced point cloud model. As-built management that once required specialists can now be handled in-house in a short time, dramatically shortening the PDCA cycle of construction management.

As shown above, LRTK’s efficiency benefits cover many aspects of field work. The advantage is not only reduction of effort in positioning but also overall efficiency gains including subsequent data processing and sharing. Field feedback includes comments like “we can’t go back to working without LRTK” and “it’s always in my pocket, so we find new uses depending on the idea,” reflecting high operational flexibility.

Data sharing and measurement flexibility through cloud integration

One major strength of LRTK is the data sharing and workflow flexibility enabled by integration with cloud services. Traditional surveying equipment required bringing field data back via USB or memory cards, importing it to a PC, and loading into CAD software—creating considerable friction. LRTK greatly simplifies these processes.

After positioning on site, you can upload data to the “LRTK Cloud” with a single button from the smartphone app. Uploaded survey point information can be shared immediately over the internet with office colleagues or clients. For example, newly measured coordinates or point clouds are plotted on a cloud map so stakeholders can view them instantly in a browser without logging in. Since measurements such as distances and areas between points can be calculated in the cloud, there is no need to perform these calculations back at the office.

Also, the cloud-based data sharing features make it easy to provide information to external parties or clients. Choose the data to share on LRTK Cloud and generate a shareable URL with one click. Providing that URL and a set password allows recipients to view and download data from the LRTK Cloud web interface. Supported formats include CSV and SIMA, which are convenient for immediate import into CAD or GIS. This eliminates cumbersome exchanges of measurement data (email attachments, physical drawings, etc.) and ensures project stakeholders always access the latest data.

Cloud integration goes beyond mere sharing. Real-time circulation of data between field and office creates new flexibility. For example, if design coordinate data is registered in the cloud during the design phase, field workers can call it up on their phones for position guidance (as in the stake-out example). Conversely, uploading as-built data from the field can automatically generate orthoimages or contour maps in the cloud for instant office sharing—processing that once required expensive software and high-performance PCs. By leveraging cloud computation, advanced measurement and analysis can be performed without burdening the device.

In short, LRTK and cloud integration create an environment where “measure in the field and share with everyone immediately” and “necessary measurements are available anytime, anywhere.” This is highly beneficial from a workstyle reform perspective, reducing information loss between field and office and dramatically improving the flexibility of surveying and measurement workflows.

Compatibility and potential of tilt-compensated GNSS with cloud integration

The combination of tilt-compensated GNSS and cloud integration is an excellent match for field DX (digital transformation). Each technology is useful on its own, but combined they produce the following synergistic effects and possibilities.

• Real-time progress sharing: Rapidly acquired large numbers of survey points from tilt-compensated GNSS can be shared via the cloud in real time so the whole team can immediately grasp site progress. For example, if daily embankment volumes are measured with a tilt-compensated GNSS-equipped device and uploaded to the cloud, the office can check as-built results on the same day. This can reduce the time lag between field and office to nearly zero.

• Centralized data management and utilization: Survey data accumulated in the cloud can be integrated into project-wide GIS maps or BIM models. Overlaying precise point clouds and coordinate data from tilt-compensated GNSS in the cloud makes it easier for stakeholders to align their understanding. Online comparisons with design drawings and construction plans facilitate early detection of rework or errors. In the future, accumulated data could be analyzed by AI to optimize construction processes or monitor terrain changes.

• Integration with new surveying methods: Tilt-compensated GNSS + cloud enables easy combination with other technologies. For example, linking with AR (augmented reality) technology allows calling up cloud design data on a smartphone and overlaying it on the real scene as an intuitive AR guide for field work. Since tilt compensation maintains accurate positioning even when the pole is tilted, AR overlays remain precisely aligned with real objects. This enables construction and surveying support that is easy for non-experts to understand.

• Expansion to machine guidance: While GNSS on heavy machinery is common on large sites, similar capabilities can be replicated on small-to-medium sites using a tablet + LRTK. Creating an environment where a machine operator can view their position and design lines on a cloud-synced tablet allows precise construction guidance. Sharing reference point information obtained with tilt-compensated GNSS through the cloud and referencing it from machinery creates flexible on-site IoT integration. Providing machine guidance-like accuracy with affordable equipment could broaden GNSS adoption across the construction industry.

Thus, tilt-compensated GNSS and cloud integration amplify each other’s strengths. The Japanese government’s initiatives such as “i-Construction” and “ICT construction” emphasize GNSS and cloud utilization. In this context, integrated systems like LRTK that combine tilt compensation and cloud functions match contemporary needs, and their application scope is expected to expand.

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

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

• Hardware: A smartphone-mountable compact RTK-GNSS receiver (LRTK device). This unit handles tilt-compensated high-precision GNSS positioning. It is portable, can be attached to a pole or monopod as needed, has an internal battery for long operation, 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 offers intuitive UI controls for starting/stopping positioning, saving points, toggling averaging or continuous measurement modes, recording photos with location, AR guidance, and more. The app connects seamlessly with the cloud for data sync and sharing with one tap.

• Cloud service: On LRTK Cloud, uploaded survey data is organized and stored per project. You can view points on a map, reproduce on-site conditions with a 3D point-cloud viewer, and automatically generate deliverables (plans, cross-sections, volume calculation reports, etc.). URL sharing makes it easy to provide external access. The cloud is not merely a storage location but a place that converts field-collected data into immediately valuable information.

• Workflow integration: By combining the hardware, software, and cloud, the formerly fragmented flow of surveying→data processing→sharing→utilization becomes continuous. For instance, share baseline coordinates obtained with LRTK at the start of the day via the cloud, have team members upload measurement data throughout the day for aggregation, and by evening compile the results for as-built checks and reporting—facilitating smooth information circulation within a single day. No paper field books or USB drives are needed; the field and office remain continuously connected by data, which is the essence of LRTK’s simple positioning.

From this overall picture, it becomes evident that LRTK is not merely a replacement for a surveying instrument but a solution that reforms the surveying workflow itself. Making high-precision positioning accessible to everyone accelerates field DX and allows tasks previously outsourced or left to later stages to be handled in real time. In other words, LRTK’s simple, high-precision positioning not only streamlines the act of “measuring” but also transforms how “measured data is immediately utilized,” enabling holistic on-site process optimization.

Conclusion: Why we recommend adopting LRTK for surveying

Finally, summarizing the points above, here are the reasons we recommend adopting LRTK.

Combining the work-efficiency and high-precision benefits of tilt-compensated GNSS with the data-utilization power of cloud integration, LRTK brings new value to surveying and construction sites. Tasks that previously required two people and significant time can be completed quickly by one person with LRTK. Moreover, collected data is immediately shared via the cloud and can be utilized by the whole team in real time.

LRTK’s intuitive smartphone app enables advanced positioning even by non-specialists. This addresses workforce shortages in the construction industry by allowing anyone to reliably ensure measurement accuracy on site. Additionally, the device’s small, lightweight, and cost-effective configuration makes it easier for small-to-medium sites and municipal bodies—previously reluctant to invest in expensive equipment—to adopt LRTK. The ability to lower initial and maintenance costs while achieving surveying DX is a major attraction.

The future expandability and extensibility of LRTK are also notable. Planned updates will continue to enhance functionality, and features such as AR-assisted construction support, photo records, and indoor positioning modes have already been implemented. LRTK is not just a surveying instrument but a platform that will continue to evolve; adopting it gives you ongoing access to the latest capabilities. This continuing improvement is another reason to recommend it.

In summary, introducing simple surveying with LRTK can simultaneously improve “efficiency,” “accuracy,” and “sharing.” LRTK enhances site productivity and safety and enables data-driven construction management for everyone. It is likely to become a standard on-site tool going forward. Surveyors, construction managers, infrastructure inspectors, and municipal staff alike should experience this new positioning solution. We expect that adopting LRTK for surveying will help your sites take the next step forward.

FAQ

Q: Can you really position accurately while the pole is tilted? A: Yes. Modern tilt-compensated GNSS devices including LRTK can maintain centimeter-level accuracy even when the pole is moderately tilted. Built-in IMU sensors detect tilt angles and orientation and correct positioning data in real time. However, extreme angles or large movements can reduce accuracy, so when necessary use a monopod or combine with short-duration averaging to ensure precision.

Q: Can LRTK be used without surveying expertise? A: Yes. LRTK is designed to be user-friendly for beginners. The dedicated smartphone app displays the current location and target points in an easy-to-understand manner, and operation is intuitive with simple button presses. Coordinate system settings and calculations are automated, so accurate results can be obtained without specialized knowledge. There are cases where inexperienced workers used LRTK to carry out stake-out tasks successfully.

Q: How can field data be shared? A: Data acquired with LRTK can be uploaded to the cloud directly from the smartphone on site. Cloud-stored data can be shared instantly over the internet with office PCs or other team members. Using the cloud’s sharing feature, you can generate a URL with one click and send it to stakeholders for viewing or downloading. This eliminates complicated file exchanges and reporting, allowing everyone to always access the latest data.

Q: Can LRTK be used in mountainous areas without reception or indoors? A: High-precision positioning is possible even in areas without mobile reception. LRTK receivers can receive CLAS correction signals from Japan’s quasi-zenith satellite Michibiki (QZSS), so they can obtain direct satellite-based corrections and maintain centimeter-level accuracy without internet connectivity. However, a clear satellite visibility (open sky) is required. For indoor or underground areas where GNSS signals are unavailable, an “indoor positioning” mode allows obtaining a reference position outdoors first and then using IMU-based dead reckoning to continue positioning for a short time.

Q: Will LRTK make conventional surveying instruments unnecessary? A: In many cases, LRTK can cover routine surveying and measurement needs. It can handle tasks from reference point surveys to as-built management and stake-out guidance. However, for extremely long-range precision traverses or cases requiring special accuracy control, conventional total stations may still be more suitable. LRTK can serve as a primary field surveying tool, and combined use with existing instruments in an appropriate manner will create a more efficient and robust surveying system.