What Makes LRTK Lead the Frontline of One-Man Surveying?

Recently, a new style of surveying called "one-man surveying" has been attracting attention in the surveying world. This approach, which allows a single person to complete surveying tasks, is expected to help solve challenges in the construction and surveying industries such as labor shortages and an aging workforce. Advances in technology—like robotic total stations and high-precision GNSS positioning—have made it possible for tasks that once required multiple people to be completed by one person.

At the forefront of this one-man surveying trend is LRTK, a compact positioning device developed by Lefixea Inc., a startup originating from Tokyo Institute of Technology. By simply attaching it to a smartphone, LRTK enables centimeter-level precision positioning, promoting DX (digital transformation) on site and making solo surveying a reality. This article explains in detail why LRTK can lead the industry in one-man surveying and what its main strengths are.

Why One-Man Surveying Is in Demand

Traditionally, surveying work was carried out by a team of multiple people. For example, surveying with a total station (TS) required one person to operate the instrument while another held a prism at a remote point. A pair of a skilled surveyor and an assistant, and sometimes a recorder, was the basic setup—three people in some cases—and on large sites it was not uncommon for a team to spend an entire day on a job. Naturally, personnel and time costs were significant, and office work such as data整理 and drawing preparation remained after fieldwork. Under these conventional methods, sites already suffering from staff shortages faced even greater burdens, hindering efficiency.

However, amid population decline and shortages of skilled personnel, the challenge of "how to run sites efficiently with fewer people" has become critical, and expectations for one-man surveying are rising. Technological innovation underlies this shift. The advent of auto-tracking robotic total stations made it possible for a single operator to track and measure targets. In addition, advances in GNSS (satellite positioning) technology—especially the spread of real-time kinematic (RTK) methods—have made centimeter-level high-precision positioning possible for one person by using correction information from reference stations. National *i-Construction* initiatives and DX (digital transformation) in the construction industry are also supporting this trend, and the idea that "if one person can measure it, that's better" is gradually taking hold on job sites.

What Is LRTK? A Smartphone Positioning Device That Enables Solo Surveying

LRTK is an ultra-compact RTK-GNSS receiver used in combination with a smartphone. The device weighs about 165 g and is roughly 1 cm thick; it attaches to the back of an iPhone or similar device and connects to the phone via Bluetooth or Lightning. By doing so, the user’s smartphone instantly becomes a centimeter-level surveying instrument. Inside the device are a high-performance GNSS antenna and a battery; it operates under power and control from the smartphone. With just a pocket-sized device and a smartphone, positioning tasks that previously required setting up a tripod and multiple people can be completed by a single person. It is a groundbreaking solution that opens the era of "smartphone surveying."

The LRTK system supports network RTK, augmentation signals from Japan's quasi-zenith satellite system, and other services, enabling real-time high-precision positioning nationwide. It can receive correction data from reference stations via cellular networks using the Ntrip method, and in areas where network connection is difficult—such as mountainous regions—it can still obtain correction information directly from satellites (the CLAS signal from Michibiki) to reduce errors to a few centimeters.

Despite its simple design for easy smartphone use, the LRTK device is equipped with a battery that can sustain several hours of continuous measurement. By bringing an iPhone and LRTK to the field, you can immediately start high-precision solo surveying. The positioning accuracy is in a different class from typical smartphone internal GPS; with LRTK, you can achieve the centimeter-level accuracy required for surveying.

Key Strengths That Put LRTK at the Forefront

LRTK is garnering attention in one-man surveying because of many strengths in its features and usability. Here are the main points.

• Centimeter-level high-precision positioning: RTK GNSS positioning raises accuracy to within a few centimeters. While typical smartphone GPS has errors of around 5–10 m, LRTK provides the accuracy needed for surveying even when used by a single operator. High-precision location data can be confidently used for quality control and layout marking.

• AR navigation to assist stakeout: The dedicated LRTK smartphone app includes an AR-based coordinate navigation feature. For predefined target points, the screen shows real-time instructions like "move east by ○ cm" or "move north by ○ cm" from your current position, allowing one person to perform stakeout or layout marking accurately without getting lost. Traditional layout tasks that required several people can now be completed by a single person with a smartphone in hand.

• 3D surveying via LiDAR integration: By integrating with an iPhone’s LiDAR sensor and camera, you can easily scan the surroundings and obtain 3D point cloud data. Because LRTK assigns high-precision position coordinates to each point during scanning, you can walk around and sweep the smartphone to measure large areas of terrain and structures alone. The point cloud records details that sampling-based surveying might miss, supporting quality checks and the creation of digital twins.

• Automatic logging of positioning data and photos: Tapping the measurement button automatically saves latitude, longitude, and elevation with a timestamp. Point names are automatically numbered and listed, eliminating the need to write them down manually in a field book. Photos taken with the smartphone are automatically linked with positioning information, enabling photographic records of measured locations and reducing time spent on data整理 and human error.

• Immediate data use through cloud sharing: Survey data collected on site can be uploaded to the cloud and shared with stakeholders instantly. If you send the results from your smartphone right after measuring, supervisors and colleagues can already be reviewing the data by the time you return to the office. Coordinates and point clouds can be viewed and used on the cloud immediately, allowing rapid feedback for any missed measurements and enabling follow-up measurements on site. This minimizes rework and shortens lead times.

• Intuitive operation using a smartphone: Setting up the device is as simple as attaching the LRTK unit to a smartphone. No complicated initial configuration is required; even on a first-time site, it takes only a few dozen seconds from powering on to obtaining an RTK "FIX" status. The dedicated app has a simple, easy-to-understand interface, so less-experienced technicians can operate it intuitively. From smartphone-savvy younger staff to veteran technicians, anyone can master it with short training, enabling smooth on-site adoption.

• Affordable and easy to introduce: Low introduction cost is another major appeal of LRTK. Conventional high-precision GNSS surveying equipment with integrated antennas typically costs several million yen per unit, whereas a pocket-sized LRTK device is available for tens of thousands to a hundred thousand yen—an order of magnitude more affordable. The dedicated app is provided for free, and existing smartphones can be used, so there is no need for new dedicated terminals. There are communication fees when using high-precision positioning services, but overall initial investment and running costs are significantly lower than conventional equipment. The price range makes it accessible for small and medium-sized companies and municipalities, allowing them to enjoy improved accuracy and efficiency at low cost—another reason LRTK is chosen.

Simple Steps for One-Man Surveying with LRTK

One-man surveying with LRTK can be started by anyone following these steps.

• Prepare the device and app: Prepare the LRTK unit and attach it to the smartphone (iPhone/iPad, etc.) using the dedicated holder or case. Download and install the free "LRTK" app from the App Store or Google Play in advance.

• Set up on site: Upon arrival at the survey site, power on the LRTK device attached to the smartphone. Launch the LRTK app and connect to the device; satellite acquisition will begin and RTK positioning will start. When the app displays the RTK "FIX" status after several dozen seconds, you are ready to survey.

• Perform positioning and measurement: Move to the point you want to measure and tap the "measure" button in the app to record high-precision coordinates for that location. No assistants are required. If you need to measure a large area continuously, simply walk around while holding the smartphone—automatic point cloud scanning will occur and a 3D model of the surroundings will be generated. For stakeout tasks, use the coordinate navigation feature and follow the on-screen directions to mark target positions accurately by yourself.

• Check and share data: Measured coordinates and generated point clouds are displayed in the app immediately, and distance and area calculations can be performed on the spot. If desired, take site photos to save as records with attached positioning information. After finishing work, upload the data to the cloud with one tap from the app—stakeholders will be able to review the results by the time you return to the office. You can receive additional instructions or requests for re-measurement instantly, enabling efficient and reliable completion of surveying tasks.

Main Benefits of Introducing LRTK

The benefits that one-man surveying with LRTK brings to the field include the following points.

• Labor savings and reduced personnel costs: Tasks that traditionally required two to three people can be performed by one, helping to alleviate labor shortages and significantly reduce personnel costs. It becomes possible to cover multiple sites with limited staff, directly improving productivity.

• Shorter work time: Fast positioning and data processing dramatically shorten lead times from surveying to drawing creation, quantity calculations, and reporting. Because on-site data can be shared to the cloud immediately, tasks such as quality confirmation that previously took several days can be completed the same day.

• Improved surveying accuracy and data quality: RTK-GNSS enables centimeter-level measurements that meet accuracy requirements. Point cloud measurements capture the entire site densely, providing high-quality results without omissions. Smaller errors reduce the need for re-measurement and rework.

• Improved safety: Shorter surveying time on site reduces workers’ exposure, lowering risks such as heatstroke and accidents. Nighttime surveys and measurements on busy roads can be completed quickly, minimizing time spent in hazardous conditions.

• Reduced human error: Measurement values and photos are recorded digitally and automatically, eliminating transcription mistakes and errors from handwritten notes. It also prevents missed or unrecorded measurements, enabling reliable deliverables.

• Easier skill acquisition and reduced dependence on experts: Smartphone-centered operation is easy to understand and can be learned quickly by anyone. Because surveying know-how is systematized, tasks can be performed to a consistent level of accuracy without relying on specific veteran personnel. This reduces dependence on individual experience and allows organizations to maintain stable surveying capabilities.

Proven Efficiency and Quality Improvements on Site

The effects of introducing LRTK have already been proven in the field. For example, at a civil engineering site, LRTK introduction led to a major efficiency improvement in surveying. What used to take two people a full day for as-built measurements was completed by one person in a few hours after adopting LRTK—achieving about a 70% reduction in work time. Labor costs were significantly reduced, and because LRTK enables real-time acquisition of high-density survey data, the entire site could be thoroughly measured, improving accuracy and quality. The detailed point cloud data obtained allowed confirmation of areas that sampling-based surveys had missed, contributing to early detection of construction mistakes and prevention of rework.

Local governments have also started using LRTK for DX in field surveying. For example, Fukui City quickly introduced the LRTK system in 2023 for on-site disaster recovery surveys. Because staff can immediately start smartphone-based surveying as soon as they discover damaged areas, the need to shuttle between sites and the office is reduced and detailed damage records can be compiled more quickly than before. As a result, the lead time from planning recovery measures to starting construction was shortened, significantly contributing to faster recovery and cost savings. The relatively low introduction cost was also attractive to the municipality, allowing them to perform surveying in-house rather than outsourcing and thereby cutting costs and building internal technical capacity. In this way, one-man surveying with LRTK is producing solid results even in the public sector, and other municipalities are now considering adoption based on these outcomes.

Conclusion

LRTK is changing conventional field practices with its many strengths that make one-man surveying possible. It enables anyone to handle centimeter-accurate positioning easily, turning surveying tasks that once required multiple people into surprisingly simple operations. LRTK supports smart working styles—measuring the site efficiently alone and sharing data instantly for immediate use—and is a reliable partner leading on-site DX at the forefront. In addition, the LRTK series is compatible with the Ministry of Land, Infrastructure, Transport and Tourism’s *i-Construction* initiatives, strongly supporting digitalization in the construction industry.

Use the highly accurate yet easy-to-use LRTK to achieve labor and efficiency savings at your site. If you’re interested, please visit the [LRTK official site](https://www.lrtk.lefixea.com) and feel free to contact us via the [inquiry form](https://www.lrtk.lefixea.com/contactlrtk). Experience LRTK’s "simple surveying" that you can start with just a smartphone, and take your site to the next stage.