LRTK Makes It Possible! Dramatically Improve the Accuracy and Efficiency of One-Person Surveying

On construction and surveying sites, chronic labor shortages and demands for higher productivity have brought attention to “one-person surveying,” where a single operator completes surveying tasks alone. Imagine how much more efficient site work would be if you could perform accurate surveys entirely on your own, without anyone’s help.

Traditionally, surveying was typically done by teams of two, but advances in technology have made high-precision surveying by a single person possible. Particularly noteworthy is LRTK, which leverages the latest RTK-GNSS technology. This article explains how using LRTK can dramatically improve both the accuracy and efficiency of one-person surveying.

What Is One-Person Surveying?

One-person surveying, as the name implies, refers to surveying operations carried out by a single person. Normally, surveying is conducted by two people: one operating the instrument and another holding a staff or prism. For example, with a total station, one person looks through the telescope to aim at the target while the other holds a prism at a distant point. However, in one-person surveying, these steps are completed by a single operator. In recent years, total stations with auto-targeting and auto-tracking functions, as well as RTK-GNSS positioning devices that obtain high-precision positions in real time, have made it possible for one person to measure even at distant points.

Benefits of One-Person Surveying

The growing interest in one-person surveying stems from severe labor shortages and the need to cut costs in the construction and surveying industries. Traditional two-person surveying required time and expense to secure personnel and coordinate schedules, but if one person can finish the work alone, these burdens can be greatly reduced. The main benefits are summarized below.

• Reduced labor costs: Because only one person is needed for surveying, labor costs can be significantly lowered.

• Flexible scheduling: There is no need to arrange other personnel, so surveying can be performed whenever necessary, according to site conditions.

• Improved work efficiency: With no need for verbal cues or team coordination, work proceeds more smoothly. One person can work steadily even on large sites or in noisy environments, reducing time loss.

• Stable quality: When an experienced operator performs tasks consistently alone, surveying methods become standardized and data variability decreases. Having the same person measure each time yields consistently reliable results.

As described above, consolidating the personnel needed for surveying from two to one effectively doubles the workload per person and directly boosts overall site productivity.

Challenges of One-Person Surveying

On the other hand, there are several challenges (drawbacks) to one-person surveying. Although technological advances have made solo surveying possible, the following points require attention.

• Equipment preparation burden: A single operator must carry and set up all equipment such as surveying instruments and tripods, increasing the physical load. This can be especially concerning when installing equipment in places where securing safety is difficult, such as alongside roads.

• Need for specialized equipment: One-person surveying often requires advanced surveying instruments like auto-tracking total stations. Such specialized equipment tends to be more expensive than standard instruments, raising initial investment costs.

• Advanced skills and experience: Because one person performs all surveying steps alone, operators need high skills and extensive experience. Even automated equipment may have issues or limitations in certain situations, requiring flexible responses such as switching to manual operation.

Nevertheless, these challenges are being resolved one by one through new technologies. For example, the equipment burden can be eased with pocket-sized compact devices, and cost barriers can be lowered by using more affordable devices instead of expensive specialized instruments. The need for high operator proficiency can be mitigated by intuitive smartphone apps that assist operation. LRTK is precisely an example that embodies these solutions.

What Is LRTK?

LRTK is a pocket-sized, all-purpose surveying device developed by Lefixea, a startup originating from Tokyo Institute of Technology. It is an ultra-compact RTK-GNSS receiver that can be attached to a smartphone (iPhone/iPad), turning the phone into a surveying instrument with centimeter-level accuracy. Weighing about 125 g, it is very lightweight and can be attached to a dedicated smartphone case with one touch, allowing it to be taken out of a pocket and used anytime. It has a built-in battery for long continuous measurements in the field.

This small device can be used for a variety of purposes, from positioning (point measurements) to point cloud measurement (3D scanning using the phone’s LiDAR), layout staking, and displaying design data via AR (augmented reality). Acquired data are automatically calculated and recorded on the smartphone and can be uploaded to the “LRTK Cloud” with a single button for sharing. Using an optional monopod (pole) allows stable placement of the device and makes height offset correction easy to set within the app.

On sites, LRTK is quietly creating a boom as a “surveying instrument that fits in your pocket,” and its affordable price is making it realistic to equip “one per person.” Previously, one-person surveying required expensive equipment such as auto-tracking total stations, but LRTK significantly lowers those barriers. Its pricing is very reasonable compared to traditional surveying instruments, enabling high-precision surveying while keeping introduction costs down—an important advantage for sites. Local governments and construction companies have already started adopting it, and it is proving useful in a wide range of applications, such as disaster-site surveying, infrastructure inspections, and land surveys.

Basic operations of LRTK are surprisingly simple. For a single-point measurement, for example, you attach the LRTK receiver to a pole, place the pole tip at the point to be measured, and tap the positioning button in the smartphone app. The latitude, longitude, and height of that point are then recorded instantly, and point names, measurement times, and satellite reception status are saved automatically. There’s no need to take notes in a paper field book; all data are managed digitally, preventing recording errors.

Example workflow for surveying with LRTK:

• Attach the dedicated case to your smartphone and mount the LRTK receiver on it.

• Launch the LRTK app and establish connection to a reference station (via an internet-based correction service or Michibiki CLAS).

• At the point to be measured, place the receiver at the specified position on the pole tip and tap the positioning button in the app.

• The measured latitude, longitude, and height data are automatically saved to the smartphone. Add point names or notes as needed.

• Upload accumulated data to the cloud and share with the office PC or stakeholders.

High-Precision Surveying Achieved with LRTK

One of LRTK’s outstanding features is its positioning accuracy. General smartphone GPS can have errors of several meters, but LRTK uses RTK-GNSS technology to achieve high-precision positioning with errors of only a few centimeters or less. RTK positioning employed by LRTK improves accuracy by using signals from multiple satellite positioning systems (GPS, GLONASS, GALILEO, and Japan’s Michibiki, etc.) and performing relative positioning with a reference station. Standalone GNSS positioning normally experiences meter-level offsets due to ionospheric or clock errors, but RTK can correct these in real time, reducing errors to just a few centimeters to a few millimeters. This is a reliable method used in specialized fields like civil engineering surveying, and by supporting RTK, LRTK achieves accuracy comparable to traditional surveying instruments. Vertical (elevation) accuracy is also on the order of a few centimeters, which is sufficient for typical construction management. In practice, LRTK positioning has shown horizontal errors of about 1–2 cm for single measurements, and averaging multiple observations can achieve sub-centimeter accuracy (for example, around 8 mm).

LRTK can also achieve high-precision positioning even without an internet connection by receiving the centimeter-level augmentation service (CLAS) broadcast from Japan’s quasi-zenith satellite Michibiki. Therefore, accurate surveying can be conducted even in mountainous areas or disaster sites where cellular signals do not reach. In fact, LRTK has been used in earthquake disaster area surveys and proved powerful for rapid surveying in situations where bringing in large equipment was impossible.

The LRTK app can convert the acquired latitude and longitude data in real time to the Geospatial Information Authority of Japan’s plane rectangular coordinate system and elevation (geoid height) and record them. Information such as point names, measurement date and time, and satellite reception status is saved automatically, making it easy to verify accuracy later or organize results. Such high-precision, reliable surveying becomes possible for a single operator thanks to LRTK.

Dramatic Improvements in Surveying Efficiency Enabled by LRTK

Introducing LRTK is expected to dramatically improve surveying efficiency on site. Compared with traditional surveying methods, the following efficiency gains can be realized.

• Mobility and ease: With an LRTK that fits in your pocket and a smartphone, surveying can be completed without carrying heavy tripods or large equipment. You can walk around the site and quickly measure any points of interest, even between tasks. Additionally, because LRTK uses GNSS positioning, it does not require a direct line of sight between the survey point and the instrument, making it easier to measure points that were previously difficult due to obstructions.

• Improved personnel efficiency: Since one person can survey, there is no need to allocate other personnel, allowing surplus staff to be assigned to other tasks. Not tying up multiple people for surveying increases overall team productivity.

• Real-time data sharing: Measurement data can be uploaded to the cloud immediately and shared with office staff in real time. Cloud-stored positioning data can be downloaded in CSV or SIMA format, making it easy to import into existing design and surveying software. Sharing the cloud data access URL with stakeholders enables them to view the results directly, facilitating smooth information sharing with subcontractors and clients. The ability to confirm and report measurement results on site reduces rework and waiting times and leads to quicker decision-making.

• Time savings through multifunctionality: LRTK supports not only point surveying but also point cloud scanning, photographic records, and AR display of drawing data. Because you don’t need separate devices or steps, you can perform the entire workflow together, resulting in significant time savings.

• Easy operation: The dedicated app automates positioning and various calculations with simple button operations, making it easy to use even without advanced expertise. Even those unfamiliar with complex machinery can become proficient quickly and perform accurate surveys. Using familiar smartphones also reduces resistance among younger workers, facilitating smoother skill acquisition and succession.

By leveraging LRTK in these ways, surveying operations can be streamlined across the board, contributing significantly to overall site productivity improvements and cost reductions.

For example, scanning a work area with LRTK and a smartphone’s LiDAR can allow on-the-spot volume calculations for progress management, or using AR to overlay design lines on the real ground to confirm stake-out positions can be done easily by one person. Tasks that formerly required specialized surveying equipment or multiple personnel can be completed quickly with LRTK.

Also, baseline surveying that previously required two people using a total station can now be done by a site supervisor alone, walking between points with drawings in hand and performing successive measurements with a smartphone. There is no need to carry heavy equipment and set it up or to send signals back and forth with a partner; all required coordinates can be acquired quickly, leading to substantial time savings.

Case Studies: Efficiency Gains Achieved with LRTK

Voices from actual sites attest to LRTK’s effectiveness. At a medium-sized construction site, surveying that had taken a two-person team over half a day before LRTK was introduced can now be completed by one person in about two hours, significantly reducing the person-hours spent on surveying. Site supervisors reported, “There’s no waiting for surveying anymore, so we can focus on other tasks,” and “I can measure points myself while checking the drawings, so arrangements go smoothly.”

At another civil engineering site, scheduling had been difficult because surveying specialists had to be called in each time, but after equipping the site with LRTK, site technicians could perform surveying during downtime. This allowed surveying to be inserted between operations, eliminating waits and shortening construction periods. In this way, on-site personnel highly evaluate one-person surveying with LRTK as a “tool that changes site norms.” These examples demonstrate that LRTK is making labor-saving and efficiency improvements in surveying a reality on the ground.

Conclusion

One-person surveying is expected to become increasingly widespread as a new surveying style that contributes greatly to alleviating labor shortages and improving work efficiency. Among solutions, LRTK expands the possibilities of one-person surveying by solving traditional challenges with innovative technology. By using LRTK, surveying tasks that previously required two people can be transformed into simple surveys that a single person can perform safely and accurately.

With a lightweight, compact device and a smartphone app enabling high-precision surveying, the barrier to surveying is lowered, bringing an era in which anyone can quickly take measurements on site whenever needed. Because site staff without special qualifications can obtain high-accuracy surveying data with LRTK, this technological innovation will also accelerate DX (digital transformation) in the construction industry.

Adopting one-person surveying technology like this is expected to greatly contribute to productivity improvements across the construction industry, which faces severe labor shortages.

LRTK dramatically improves the accuracy and efficiency of one-person surveying and is poised to change on-site work styles significantly. If you are interested in productivity improvements through one-person surveying, be sure to check details on the [LRTK official site](https://lrtk.lefixea.com). LRTK may bring new possibilities to surveying on your site.