One-Person Surveying Revolution｜The Key to Improved Work Efficiency Lies in LRTK

In recent years, the common sense of surveying has been changing dramatically. A style called "one-person surveying," which allows surveying work to be completed without relying on others, has been attracting attention on job sites, and a movement that can rightly be called a surveying revolution is underway. Driven by technological advances and the need to solve on-site challenges, the era has arrived in which tasks that once required two or more people can now be handled by a single person. The cutting-edge solution expected to be the key to improving work efficiency is called LRTK. In this article, we explain in detail the background of why one-person surveying is needed now, the challenges of traditional surveying, the mechanisms and effects of one-person surveying, and the innovative technology of LRTK and how its introduction changes field work. Finally, we present the concrete workflow for solo surveying using LRTK and recommend adopting this revolutionary method in your surveying operations.

Why is one-person surveying needed now?

The construction and civil engineering industries are facing severe labor shortages and an aging of skilled technicians. Traditionally, surveying was carried out by teams of two or more people, but with fewer young personnel, there is pressure to cover many sites with a limited number of people. In addition, rising labor costs and the trend toward work-style reform mean that methods to efficiently perform tasks with fewer personnel are needed. Against this backdrop, the idea that "if one person can survey, that's even better" has spread, and interest in one-person surveying has grown year by year.

Furthermore, government-led *i-Construction* initiatives and the industry's push for DX (digital transformation) in construction are also supporting this trend. As measures to streamline on-site work through ICT technologies progress, ICT-driven one-person surveying is expected to be a solution that addresses both labor shortages and productivity improvement. With technological innovation and industry needs converging, now is precisely the time when one-person surveying is being demanded.

Traditional surveying work and its challenges

First, let's organize the problems that traditional surveying work has had. In conventional surveying, it was common to operate heavy equipment with a team, investing significant time and effort. The main issues that arose included the following:

• Burden of personnel and cost: Surveying typically required at least two people, and sometimes three or more (for example: with a total station, one person operates the instrument while another holds the prism at a distant point). This led to a large personnel cost burden and placed a heavy strain on sites suffering from chronic staff shortages.

• Long working hours: When there are many survey points across a large site, it was not uncommon for teams to spend an entire day moving around the site to take measurements. Even after surveying, plotting points on drawings and performing quantity calculations back at the office took time, so post-processing consumed time, and overall lead times tended to be long.

• Difficulty of real-time utilization: It was inefficient that data obtained on site could not be immediately used for construction or decision-making. Survey results had to be taken back and organized before they could be used, and measurement errors or omissions were sometimes discovered late, requiring re-surveying.

• Risk of human error: Tasks such as transcribing measurements into handwritten field books or later linking photos taken with the camera to survey points were prone to mistakes. Writing down numbers incorrectly, mixing up photos, or failing to record location information were common human errors.

• Dependence on skilled personnel: Operating advanced instruments like total stations requires specialized skills and tended to rely on certain veterans. If such a person was absent, construction could be delayed with a "surveying wait," leading to task dependence on individuals.

Given these issues of personnel shortages, inefficiency, and error risk in traditional surveying methods, one-person surveying that can be completed by a single operator has come to be expected as a trump card to solve on-site problems.

What is one-person surveying? Basic mechanism and benefits of introduction

One-person surveying is, as the name suggests, a method in which surveying work is completed by a single operator without an assistant beside the surveying instrument. The realization of this method is backed by recent dramatic advances in surveying technology. For example, with the advent of automatically tracking robotic total stations, the instrument can automatically track the prism, enabling one person to perform angle and distance measurements alone. Also, the development of GNSS positioning technologies (satellite positioning) is a major factor. Among these, RTK-GNSS (real-time kinematic positioning) combines correction data from a base station and a rover to achieve real-time positioning accuracy on the order of centimeters, making it possible for one person to measure positions with accuracy comparable to traditional surveying.

Introducing one-person surveying brings many benefits. If one person can perform the work, it leads to labor savings and reduced personnel costs, and eliminates the need to wait for someone to be available, allowing measurements to be taken whenever needed. This reduces wasted time from waiting on scheduling, shortens construction periods, and speeds decision-making. In addition, by leveraging digital technology, high-accuracy data can be acquired and shared on-site, reducing errors associated with paper field books and manual processes and producing high-quality surveying results. The new norm that "if one person can measure accurately, that's preferable" is spreading, and the benefits of introducing one-person surveying directly translate into improved productivity across the site.

The emergence of LRTK and its innovativeness

A revolutionary tool that strongly supports such one-person surveying is LRTK. LRTK is an ultra-compact RTK-GNSS device developed by Reflexia Inc., a startup from the Tokyo Institute of Technology, and it is a solution that essentially turns a smartphone into a high-precision surveying instrument. The compact body, weighing approximately 165 g and about 1 cm (0.4 in) thick, houses a high-performance antenna and battery. By attaching this to a smartphone such as an iPhone or iPad (fixed with a dedicated case or magnet) and connecting via Bluetooth or Lightning, a handheld smartphone instantly becomes a surveying instrument capable of centimeter-level positioning (cm level accuracy, half-inch accuracy). Whereas conventional surveying required setting up tripods and installing equipment weighing several kg, surveying can now be completed with a pocket-sized device plus a smartphone. This is truly a groundbreaking arrival that ushers in the era of "smartphone surveying."

LRTK's innovation is not limited to ease of use. It supports advanced RTK methods, and in Japan it can utilize the Geographical Survey Institute's electronic reference point network through network RTK (Ntrip) or take advantage of the quasi-zenith satellite system "Michibiki" free centimeter-level augmentation signals (CLAS) to correct positioning errors in real time to within a few centimeters (cm level accuracy, half-inch accuracy) anywhere in the country. Even in mountainous areas or disaster sites without cellular coverage, as long as the sky is open, correction data can be received directly from satellites to enable high-precision positioning. Despite its simple smartphone-powered and -controlled design, it includes a battery that can endure several hours of continuous measurement, and the ease of being able to start centimeter-accuracy surveying simply by bringing a smartphone and LRTK to the site overturns conventional wisdom. LRTK, which makes it possible for one person to handle stakeout (layout), as-built management, and even 3D measurement, is the key technology of the one-person surveying revolution.

LRTK technologies that balance accuracy and speed (RTK-GNSS, smartphone integration, AR features, etc.)

LRTK can achieve both high accuracy and work speed by cleverly combining state-of-the-art technologies. Here are the main technical features.

• Centimeter accuracy via RTK-GNSS: LRTK's greatest feature is the improvement of GNSS positioning accuracy. Typical smartphone-built-in GPS has positioning errors of about 5–10 m, but LRTK reduces errors to a few centimeters by applying RTK corrections. By analyzing signals from multiple satellites and removing error factors through comparison with base station data, tasks that require strict accuracy such as boundary surveys and as-built verification can be handled by one person. Compared with standalone GPS positioning or manual tape measurements, LRTK offers substantially higher accuracy and delivers the reliability necessary to ensure measurement quality.

• Ease and mobility through smartphone integration: No special controller or complicated setup is required; simply attach the device to the smartphone you normally use and launch the app to prepare for surveying. Even on a first job, it takes only a few dozen seconds to acquire satellites and obtain an RTK fixed solution. The dedicated app's interface is simple and intuitive, so technicians with limited experience with specialized equipment can become proficient in a short time. Surveying know-how is aggregated and standardized in the app, enabling anyone to produce consistent results. Because each person can carry one in their pocket, the mobility to take measurements as needed is excellent. For example, using an optional lightweight pole (monopod) makes it easy to achieve height-direction accuracy, and an offset correction from the ground to the receiver can be set with a single button in the app. Compared with conventional surveying instruments, it is overwhelmingly easy to handle and dramatically improves on-site footwork.

• AR navigation to assist solo stakeout: LRTK's smartphone app includes a coordinate navigation function. For pre-set target coordinates, the app displays in real time how far and in which direction to move from your current location—for example, "east 5 cm (2.0 in), north 10 cm (3.9 in)." By making fine adjustments while holding the smartphone as directed, stakeout (layout) work that previously required multiple people can be accurately performed by one person. The app can also overlay guidance on the smartphone camera view in AR, so when looking at the site through the screen a virtual stake marker or arrow is displayed at the target point. As you approach the target, the marker locks into the intended place, allowing even first-time users to locate installation points accurately without confusion. This AR navigation feature intuitively guides even inexperienced personnel to target coordinates and strongly supports solo stakeout and layout tasks.

• 3D point-cloud measurement via LiDAR scanning: With LRTK, one person can easily perform surrounding three-dimensional measurements. By linking with an iPhone's LiDAR sensor and camera functions and walking around while scanning terrain and structures, you can obtain high-accuracy 3D point-cloud data with attached positional coordinates. Thanks to the precise positioning information provided by LRTK, the captured point cloud can be used directly as a detailed three-dimensional model of the as-built condition. Large areas can be efficiently covered, and details that manual surveying might overlook can be recorded. Point-cloud data can be effectively used for overall as-built understanding, earthwork volume calculations, and displacement monitoring. Whereas professional laser scanners or drone surveying required expensive equipment and post-alignment work, LRTK enables anyone to quickly capture point clouds with just a smartphone, a major advantage.

• Automatic recording of positioning data and photo linkage: Survey results obtained with the LRTK app are all automatically recorded digitally. By tapping the measurement button, the latitude, longitude, and height at that moment are saved with timestamps and satellite reception status, and point names are automatically numbered and accumulated in a list. There is no need to transcribe numbers into paper field books. Photos taken with the smartphone are automatically tagged with capture coordinates and orientation, making it immediately clear later which location and direction each photo corresponds to. This prevents human errors such as miswriting measurement values, omitting records, or failing to link photos to points, and ensures on-site data are recorded accurately and completely.

• Real-time utilization through cloud sharing: Another strength of LRTK is the ability to quickly share positioning data to the cloud on site. With a one-tap operation in the app, coordinate lists and point-cloud data can be uploaded to the cloud immediately, and the positioning information acquired on site is plotted on an online map. Colleagues in the office or clients can view the latest survey results via a browser before the surveyor returns. Uploaded data can be immediately inspected on the LRTK web cloud service; survey points are plotted on a map and each point's coordinates, notes, and photos can be viewed. 3D point-cloud data can be displayed in three dimensions in the browser, so details can be understood without being on site. No specialized software is required: sharing a URL allows clients or remote teams to access the latest information. Being able to use measured data immediately in the next process prevents rework and speeds decision-making. Seamless connection between site and office enables total speed improvements including post-survey data utilization.

As shown above, LRTK makes it possible to "quickly and easily acquire and share high-accuracy data" through cutting-edge technologies, supporting productivity improvements for one-person surveying.

How LRTK changes on-site operations (assumed scenarios)

So, what changes on-site when LRTK is introduced? Here, we introduce changes one-person surveying brings to field operations using hypothetical scenarios and case examples.

In one construction site case, LRTK introduction reportedly greatly improved surveying efficiency. What used to take two-person teams a full day to measure as-built conditions was completed by one person in a few hours after introduction. This was roughly a 70% or more reduction in working time, significantly reducing labor costs. Furthermore, because LRTK can obtain dense high-accuracy measurement data in real time, even fine details were measured without omission, preventing rework due to missed measurements. Survey results were immediately shared to the cloud, allowing supervisors to review and issue instructions before the surveyor returned to the office, smoothing coordination between site and headquarters.

Local government applications have also begun to appear. For example, Fukui City was quick to introduce the LRTK system for damage surveys at disaster recovery sites in 2023. When staff discover damaged areas, they can immediately start smartphone surveying on site, eliminating multiple trips between the field and the office and enabling detailed damage records to be produced in a shorter time than before. As a result, the speed of drafting restoration plans improved and initial response was accelerated. In this way, one-person surveying that allows measurements whenever needed is starting to show its power in disaster response and infrastructure inspection work.

The introduction of one-person surveying transforms site operations. Even if the surveyor is occupied with other tasks, anyone who brings an LRTK to the site can immediately perform surveying. The traditional delays—"let's call the surveying team later" or "let's wait for a surveyor to arrive"—disappear, and the ability to obtain required data when needed improves overall site efficiency and flexibility. Consequently, shorter construction periods, thorough quality control, and faster on-site decision-making occur across the board, and one-person surveying with LRTK fundamentally revolutionizes how on-site operations are conducted.

Introduction steps: Workflow for solo surveying using LRTK

As we have seen, LRTK strongly supports one-person surveying. So how is one-person surveying using LRTK actually carried out? Below is the basic workflow step by step.

• Survey preparation: Before starting work on site, attach the LRTK device to your smartphone and launch the dedicated app. On the app, check the current positioning mode (GNSS reception status) and the reception status of correction information to confirm that centimeter-level accuracy (RTK "Fix" solution) is being achieved. No special equipment settings are required; turning on the power and launching the app completes preparation in a short time.

• Point measurement (measure): Move to the point you want to measure with the device and press the app's "Measure" button at that point. For example, when measuring a point on the ground, place the pole tip (stone tip) supplied against that point and tap the button on the smartphone screen. At that instant, high-accuracy latitude, longitude, and height data are obtained. If there are multiple points to measure, simply move and tap repeatedly to measure them one after another.

• Data recording (record): When you press the measurement button, the positioning data is automatically saved on the smartphone. The record includes date/time, point number, positioning status (e.g., Fix solution = high accuracy or Float solution = somewhat reduced accuracy), and more. The LRTK app also performs coordinate transformation to Japan's plane rectangular coordinate system and automatic geoid height calculation, so practical coordinate values are available on site immediately. You can name each point or leave notes as needed, enabling detailed point management without paper field books.

• Upload and share to cloud (share): After measuring a set of points, upload the data to the cloud with one tap from the app. Integrated with web services like LRTK Cloud, the positioning information obtained on site is instantly plotted on an online map. Colleagues in the office or clients can view the latest survey results via a browser, eliminating the need to bring data back via USB or transcribe handwritten notes; site and office information can be shared seamlessly.

• Data utilization: Surveying data shared to the cloud can be used directly for drawing creation, volume calculations, report writing, and other subsequent tasks. For example, you can measure the distance between two points or the area of an enclosed region on the cloud, download point-cloud data and import it into design software, and smoothly hand off data to the next stage. Photos taken on site are also saved with precise positional information, allowing you to review situations later while cross-referencing photos and points.

With this workflow, LRTK enables all steps—measure → record → share → utilize—to be completed by a single person. Because data can be shared immediately after measurement, you can proceed to the next task right away, greatly shortening overall lead times. There is no complicated post-processing or waiting for data transfer, and the real-time connection between site and office delivers workflow efficiency that, once experienced, becomes indispensable.

Conclusion and recommendation for introduction

The one-person surveying revolution underway in the world of surveying is indeed a boon for industries struggling with labor shortages. By adopting cutting-edge technologies like LRTK, one person can perform safe, high-accuracy surveying, achieving both reduced personnel costs and improved work efficiency. Without relying on manpower-heavy approaches as before, digital capabilities enable precise data to be acquired, shared, and used instantly, dramatically enhancing site productivity and quality control.

LRTK is designed with a low barrier to entry. The dedicated app is provided for free, and the device itself is far more affordable than conventional large GNSS survey equipment. There is no need to purchase expensive dedicated controllers or stationary units, and with just a smartphone in hand, you can start solo surveying today. The affordable price point makes it realistic for small- and medium-sized companies and municipalities to adopt one device per worker. LRTK overturns the traditional notion of "one set of surveying equipment per team" and creates an environment in which "each person has one device and can measure anytime."

By dramatically improving surveying efficiency and flexibility through one-person surveying, you can perform detailed measurements and previously deferred record-keeping that were once impossible due to labor shortages. The revolution is already underway on sites, and voices attesting to the difference from conventional methods are increasing. As the norms of surveying change, consider introducing LRTK-based one-person surveying at your sites. By incorporating the latest technology, you can strengthen on-site capabilities while balancing efficiency and accuracy, taking a decisive step toward next-generation construction practices. Embrace the one-person surveying revolution and gain a significant advantage in future site operations.