LRTK Revolutionizes One-Man Surveying｜The Norms of Solo Work Are Changing!

Recently, the keyword "one-man surveying" has been attracting attention in the surveying industry. Driven by labor shortages and work-style reforms, the traditional view that surveying must be done by a team is being reconsidered, and a new style that allows a single technician to complete surveying tasks is in demand. This article explains the background behind the rising interest in one-man surveying and the issues with conventional methods, describes how solo surveying has been made possible by new technologies, and details the features and benefits of the cutting-edge tool at the center of this change: LRTK. Learn how LRTK is revolutionizing solo work and what changes it can bring to on-site efficiency.

Background: Why One-Man Surveying Is Drawing Attention and the Traditional Challenges

Surveying work performed at construction and civil engineering sites is an essential process for quality control and as-built verification. However, it has traditionally been carried out by multiple-person teams. For example, with total station surveying, one person operates the instrument while another stands at the target point holding a prism some distance away. Such manpower-dependent surveying has become a heavy burden amid worsening staff shortages and an aging workforce. The conventional approach also has the following problems:

• Personnel costs and availability issues: Because a two- to three-person setup is assumed, sites with insufficient staff often experience surveying delays. There is also the cost of assembling a skilled surveyor and assistants.

• Time and labor burden: On large sites where hundreds of points must be measured, even multiple people can take a full day or more. Data processing and drawing production at the office after surveying are also required, extending overall lead time.

• Risk of human error: Recording survey points and values on paper notes can lead to transcription mistakes, and photos may not be linked to the correct points. Sometimes errors go unnoticed on site and require re-surveying later.

• Skill concentration in individuals: Operation of advanced surveying equipment and experience tend to be concentrated in veteran staff, so if a particular person is absent, work can stall. Standardizing skills across the site has been a challenge.

Against this backdrop, demand for "completing surveys efficiently by a single person" has surged, and attention to one-man surveying is rapidly increasing.

Technological Innovations That Enable Solo Surveying

To complete surveying alone, the power of modern technology is indispensable. Fortunately, surveying technology has advanced dramatically in recent years, and a variety of solutions that support one-man surveying have emerged. Representative examples include the use of robotic total stations and GNSS (GPS) positioning.

• Robotic total stations: A total station with automatic tracking allows the instrument to follow the prism automatically, enabling distance and angle measurements without an assistant even when operated by one person. However, line-of-sight is required, the equipment is expensive, and skilled handling is necessary.

• RTK-GNSS positioning: Advances in satellite positioning technology are also supporting one-man surveying. In particular, GNSS using the RTK (Real-Time Kinematic) method combines correction information from a base station and a rover to achieve centimeter-level positioning accuracy in real time. Because it can provide high-precision positioning over wide areas without line-of-sight constraints, RTK-GNSS is suitable for single-person layout work and as-built measurements. National initiatives and the industry’s push for ICT utilization through i-Construction and DX (Digital Transformation) are promoting RTK-GNSS adoption, making single-person surveying using RTK-GNSS an emerging standard in the field.

More recently, solutions that combine smartphones with these high-precision positioning technologies have appeared, making one-man surveying even more accessible. The idea is to turn a ubiquitous smartphone into a high-precision surveying instrument. Leading the way is LRTK, a compact device developed by the Tokyo Institute of Technology spin-off company, Reflexia Inc.

What is LRTK? One-Man Surveying Using a Smartphone

LRTK is an ultra-compact RTK-GNSS receiver designed to be attached to a smartphone. Weighing only about 160 g and about 1 cm thick, the unit contains an antenna and battery and connects to a smartphone via Bluetooth or a Lightning connector. Start the compatible app and acquire satellites, and the palm-sized device plus a smartphone can deliver centimeter-level positioning. Where surveying once required tripods and stationary instruments, it can now be completed with a pocket-sized device + smartphone.

Attach LRTK to a smartphone and it instantly becomes a portable "smartphone surveying device." For example, with an iPhone and LRTK, a single person can perform layout (stakeout), as-built management, and even 3D terrain scanning on site. It eliminates the need for expensive dedicated equipment and multiple personnel, and its portability allows quick, on-the-spot surveying anytime, anywhere. LRTK is attracting attention as a truly groundbreaking tool that revolutionizes one-man surveying.

Let’s look at the specific functions and features that LRTK offers.

Key Functions and Features of LRTK

• Centimeter-level high-precision positioning: LRTK’s biggest feature is GNSS-based positioning with errors of only a few centimeters. Standard smartphone GPS typically has errors of about 5–10 meters, but LRTK uses the RTK method for real-time corrections, achieving positioning accuracy sufficient for setting boundary stakes and as-built verification. Because it can acquire high-precision absolute coordinates, boundary surveys and fine as-built measurements that were difficult to perform solo are now possible.

• AR-guided stakeout coordinate navigation: The LRTK smartphone app includes a navigation function that guides users to pre-set target coordinates. Just move the phone according to real-time guidance displayed on screen—e.g., "5 cm east, 10 cm north"—to pinpoint the staking location accurately. The app can overlay virtual markers on the camera view via AR, enabling even first-time users at a site to set stake positions without confusion. Positioning tasks that previously required several people can be handled smoothly by a single person.

• 3D point cloud surveying using LiDAR scanning: LRTK can also work with the LiDAR sensor and cameras in iPhones to convert site terrain and structures into 3D point cloud data on the spot. By scanning the surroundings while walking with the smartphone, you can obtain a point cloud model with high-precision coordinates assigned to each point. This captures details that were previously overlooked, allowing comprehensive as-built understanding, volume calculations, and displacement monitoring. Wide-area 3D surveying is achievable with just a smartphone—no expensive laser scanners or drones required.

• One-tap positioning and automatic logging: At the point you want to measure, simply tap a button on the smartphone screen to record the latitude, longitude, and elevation at that moment. The LRTK app automatically saves date/time and positioning status in the background, automatically numbers point names, and manages them in lists. There is no need to copy notes into paper field books; when you take a photo, the image is tagged with location coordinates and orientation so you can always tell which point a photo corresponds to. This eliminates tedious recording and organization tasks and prevents missed records and mistakes.

• Immediate use via cloud sharing: Survey data collected on site can be uploaded to the cloud and shared in real time with stakeholders. With a single tap on the app’s share button, recorded coordinate lists and point cloud data sync to the LRTK cloud. Supervisors and colleagues can review results in a web browser before the surveyor returns to the office, viewing plotted points, photos, and notes instantly. You can even share data with clients via a URL without specialized software, enabling on-the-spot checks and additional instructions. Quick utilization of collected data reduces rework and accelerates decision-making across the project.

• The convenience of a smartphone-mounted device: Because LRTK mounts to a smartphone, it is overwhelmingly easier to carry and set up than traditional equipment. Even on a first use, preparation—from satellite acquisition to obtaining an RTK "FIX solution"—takes only tens of seconds. The dedicated app has an intuitive interface, allowing users with limited surveying experience to become proficient in a short time. Surveying know-how is baked into the app, standardizing procedures so anyone can measure with stable accuracy. With one device per worker carried in a pocket, the mobility to "take it out and measure whenever you need" is outstanding.

Benefits of Introducing LRTK

Adopting LRTK with the functions described above brings the following on-site surveying benefits:

• Labor savings and reduced personnel costs: Surveys that formerly required two to three people can be performed by one, enabling significant reductions in staffing. Limited staff can cover multiple sites, directly reducing labor expenses and alleviating personnel shortages.

• Significant reduction in working time: High-precision positioning and automated data processing dramatically shorten the time from surveying to drawing production, quantity calculation, and reporting. For example, as-built measurements that used to take two people a full day have been completed by one person in a few hours after LRTK introduction. Time savings of over 70% have been realized, greatly improving productivity.

• Improved surveying accuracy and data quality: Precise measurements delivered by RTK-GNSS produce low-error data that contribute to quality assurance. Dense point cloud measurements capture the entire site without omissions, reducing the need for re-surveys or corrections and enabling smoother project progress.

• Improved safety: Shorter surveying times reduce on-site exposure for workers, lowering risks such as heatstroke in hot environments and accidents in high or high-traffic areas. Finishing tasks quickly as a single person minimizes time spent in hazardous conditions.

• Prevention of human error: Because measurements and photos are recorded automatically in digital form, handwriting mistakes and data transcription errors are eliminated. Centralized cloud management removes concerns about missing records, ensuring work is always based on accurate data and yielding reliable deliverables.

• Ease of learning and reduction of skill dependence: The smartphone-app-centered, simple operation makes it possible for anyone to handle the system after a short training period. Systematized surveying know-how reduces reliance on particular individuals, allowing sites to be operated with consistent accuracy even without veterans present. This helps standardize skills across the organization and supports knowledge transfer within teams.

LRTK Effects Seen in Case Studies

Let’s look at the actual effects observed when LRTK was introduced on real sites.

Construction site example: At a certain civil engineering site, LRTK implementation led to major efficiency gains in surveying. As-built measurements that previously took two people a full day could be completed by one person within a few hours using LRTK—achieving about a 70% time reduction. In addition to labor cost savings, the entire site was measured at high density, improving quality. The 3D point cloud data captured areas that were missed by sample checks, helping to detect construction errors early and prevent rework.

Local government example: Municipalities have also started using LRTK as part of their on-site DX efforts. For instance, in 2023 Fukui City quickly adopted the LRTK system for disaster recovery field surveys. Staff can immediately start surveying disaster sites with a smartphone upon discovery, reducing the need for repeated trips between field and office and enabling faster, more detailed recording of damage. This shortened the lead time from planning restoration to starting work, contributing significantly to early recovery and cost savings. Because LRTK’s initial cost is relatively affordable, it is easier for local governments to adopt, allowing them to internalize surveying work previously outsourced—reducing costs and building in-house capabilities. LRTK-based solo surveying is producing results in the public sector, and other municipalities are now considering adoption.

How to Start One-Man Surveying with LRTK

With so many advantages, LRTK is also very easy to introduce and use. Finally, let’s review the basic steps to begin solo surveying with LRTK.

• Prepare the device and app: First, obtain the LRTK device and attach it to a compatible smartphone (for example, an iPhone). Install the dedicated "LRTK" app on the phone (available for free download from the App Store or Google Play).

• Set up on site: Upon arrival at the survey site, power on the LRTK attached to the phone and launch the app. Once the device and phone connect, GNSS satellite reception begins. After waiting tens of seconds for the RTK "FIX solution" (high-precision reception state) to be obtained, you’re ready to go.

• Measure and acquire data: Move to the point you want to measure and tap the app’s "position" button to automatically record the point’s high-precision coordinates. For wide-area continuous measurements, simply walk while holding the phone to perform the previously mentioned point cloud scanning. For stakeout tasks, you can follow the on-screen guidance to accurately identify target positions on your own.

• Share and utilize results: Confirm measured points and point cloud models on the phone, attaching photos as needed. When surveying is complete, upload the data to the cloud with one tap from the app. Stakeholders can review the results before you return to the office and provide additional instructions or confirmations on the spot. This enables smooth progression to the next stage without rework.

With these steps, surveying work that once required multiple people can be smoothly completed by one person. LRTK is a powerful partner that changes the norms of "solo work." By leveraging this high-precision yet easy-to-use tool, the old notion that "surveying requires a team" will become a thing of the past. For sites struggling with labor shortages or seeking productivity improvements, now is an excellent time to introduce LRTK-enabled one-man surveying. Bring cutting-edge technology to your site, innovate your surveying practices, and update the norms together.