Complete Survey Work Alone｜LRTK for Successful One-Man Surveying

In recent years, the work style called "one-man surveying" (single-person surveying) has been attracting attention at construction and civil engineering sites. This method, which allows a single person to complete surveying tasks without relying on multiple personnel, is becoming more widespread thanks to the synergistic effect of on-site needs for problem solving and technological advances. This article explains the basic concept of one-man surveying and the reasons it is gaining attention, the necessary equipment and site preparations, the concrete workflow of "measure, record, share," and the advantages and disadvantages. It also introduces the technical overview and benefits of a new surveying solution called "LRTK" in an easy-to-understand way for beginners, and provides concrete points for efficiently conducting site surveys alone.

Challenges of Conventional Surveying and Why One-Man Surveying Is Needed

Traditionally, surveying work has been done by teams of two or more people. Typically, one person operates the surveying instrument (such as a total station) while another person stands at the measurement point with a staff (rod) or prism at a distant location. In some cases a recorder is added to form a three-person team. Such manpower- and labor-intensive surveying can be a major burden for sites chronically short of personnel. In Japan in particular, experienced survey technicians are aging while younger workers are decreasing, increasing the need to operate sites efficiently with limited staff.

Conventional surveying also tends to consume a lot of time and effort. Equipment is large and heavy, and when measurement points number in the hundreds across a large site, it is not uncommon for a team to spend an entire day on the work. Even after fieldwork, a lot of desk work remains, such as plotting measured points on drawings and calculating quantities back at the office. Because field-acquired data cannot be immediately applied to construction, efficiency is poor, and measurement mistakes or data shortages that require rework are common. Moreover, operating advanced surveying equipment requires specialized skills, so teams tend to rely on specific veterans; if those people are absent, the risk of the entire construction stopping while waiting for surveying arises. As a means of transforming these issues of personnel shortages, operational inefficiency, and error risks inherent in traditional methods, expectations for surveying methods that can be completed by one person have been growing year by year.

One reason one-man surveying is gaining attention is the dramatic recent advances in surveying technology. For example, the advent of robotic total stations has enabled instruments to automatically track targets (prisms), making tasks that previously required two people easier for a single person to perform. Advances in GNSS (satellite positioning such as GPS) technology are also notable. In particular, the use of RTK-GNSS (real-time kinematic positioning) makes it possible to combine data from a rover and a base station to obtain centimeter-level positioning in real time, allowing even a single person to perform high-precision location measurements. Furthermore, initiatives such as the Ministry of Land, Infrastructure, Transport and Tourism’s i-Construction and the construction industry’s DX (digital transformation) are accelerating the use of ICT to improve on-site surveying efficiency. With these technological innovations and increasing industry needs, the idea that "if a single person can measure accurately, that is preferable" is gradually spreading.

Equipment and Site Preparations Needed for One-Man Surveying

• Surveying equipment capable of high-precision positioning: To perform surveying alone, portable equipment that can obtain high-precision location information is essential. A representative example is an RTK-GNSS receiver. For example, the pocket-sized high-precision GNSS device LRTK can be attached to a smartphone and strongly supports single-person surveying.

• Smartphone/tablet and dedicated app: A smartphone or tablet is required to display, record, and operate data obtained from the positioning device. A familiar device is sufficient. In the case of LRTK, a dedicated smartphone app (iOS/Android) is provided that allows you to start/stop positioning, save data, and connect to the cloud with a single tap. Because the smartphone can function as the controller, intuitive operation is possible even without special knowledge.

• Communication environment (network connection): To obtain high precision with RTK positioning, it is necessary to receive correction information from a base station in real time. Therefore, in many cases an internet connection (such as a mobile 4G/5G line) is required at the site. Devices like LRTK support Ntrip, a network RTK correction service, and can obtain correction data via the smartphone. In locations where the internet is not available, it is also possible to obtain correction information using the Quasi-Zenith Satellite System (QZSS) "Michibiki" satellite augmentation signal (CLAS), although there are limits depending on the region and situation.

• Other preparations: For ensuring measurement accuracy, devices such as monopods or poles (tripods) to stabilize the instrument are useful. For example, LRTK has an optional dedicated pole that helps when placing the device on a specific ground point for measurement. Also, for long work periods, carrying spare batteries for the smartphone and positioning device provides peace of mind.

Flow of One-Man Surveying (Measure・Record・Share)

• Survey preparations: Before starting surveying on the site, attach the positioning device (LRTK) to your smartphone and launch the dedicated app. On the app, check the current positioning mode and the reception status of correction information, and confirm that centimeter-level accuracy (fixed solution) is being achieved via RTK.

• Measuring points (Measure): Move the device to the point you want to measure and press the measurement button in the app at that point. For example, when measuring a point on the ground, place the tip of the pole at that point and simply tap the button on the smartphone screen. High-precision latitude, longitude, and elevation data at that moment are obtained.

• Recording data (Record): When the measurement button is pressed, positioning data are automatically recorded on the smartphone. The record includes date and time, point number, and positioning status (e.g., fixed solution (FIX) or float solution (FLOAT)). The LRTK app also performs conversion to Japan’s plane rectangular coordinate system and automatic calculation of geoid height, so you can obtain practical coordinate values immediately on site. You can name points or add notes as needed, allowing detailed record management without a paper field notebook. When measuring multiple points consecutively, you can continue to accumulate data simply by repeating the button operation.

• Uploading and sharing to the cloud (Share): After measuring a certain number of points, you can upload the data to the cloud with one tap from the app. The system is linked to LRTK’s cloud service, and positioning information obtained on site is immediately plotted on a cloud map. Colleagues or other stakeholders in the office can also check the latest surveying results from a browser. Without the hassle of bringing data back on a USB stick or transcribing handwritten notes, you can seamlessly share information between the site and the office.

• Utilizing the data: Survey data shared to the cloud can be used directly for the next steps such as drawing creation, volume calculations, and report preparation. For example, you can measure distances between points or the area of an enclosed region on the cloud, or immediately generate as-built drawings from acquired point cloud data. This greatly reduces the time spent processing data after returning to the office and leads to overall workflow efficiency.

Advantages of One-Man Surveying

• Labor savings and reduced personnel costs: If surveying can be completed by one person, tasks that previously required two or more people can be handled with fewer personnel. This helps alleviate labor shortages and reduces personnel costs.

• Increased efficiency and rapid response: Without waiting to arrange personnel, surveys can be performed whenever needed. With one-man surveying, you can respond immediately when you want to measure a point on the spot. Reduced waiting time for arrangements contributes to shorter construction schedules and faster decision-making.

• High-precision data acquisition: Surveying using RTK-GNSS provides data far more accurate than conventional simple GPS measurements. Because centimeter-level accuracy (half-inch accuracy) can be obtained immediately, it is suitable for tasks requiring precision such as as-built management and checking against design drawings.

• Real-time information sharing: Cloud integration allows acquired data to be shared in real time with the office or other devices. Since you can share information before returning from the site, you can ask superiors or colleagues to check and receive next instructions on the spot. This reduces communication loss and helps prevent rework.

• Portability and ease of use: Devices like LRTK are small and lightweight, making them easy for workers to carry. The convenience of keeping it in a pocket and taking it out to measure when needed is a major advantage. This enables "opportunistic surveying," allowing small measurements that tend to be postponed to be completed immediately.

• Multifunctional use: The latest devices for one-man surveying are not limited to measuring points; they have a variety of functions. For example, by combining a smartphone camera or LiDAR you can capture surrounding point clouds (3D data), or use AR functionality to project planned lines from drawings onto the site for stakeout. This allows a single person to perform both surveying and site documentation/verification simultaneously, reducing redundant work and further improving efficiency.

Disadvantages and Precautions of One-Man Surveying

• Dependence on the positioning environment: High-precision positioning is affected by satellite signals and communication conditions. In places where GNSS signals are difficult to receive, such as in the canyons between buildings or mountain areas, sufficient accuracy may not be achieved. In areas without network coverage, network-based RTK corrections cannot be received (while LRTK supports satellite augmentation signals, there are limits depending on region and conditions). It is important to understand the measurement area environment before work and, if necessary, prepare to combine conventional methods.

• Power management and durability of equipment: One-man surveying relies entirely on the smartphone and positioning device, so if the battery dies or the device malfunctions, work will be interrupted. For long surveys, carry spare batteries and fully charge devices in advance. Pay attention to device management in the field, such as waterproofing for rainy conditions and heat prevention in direct sunlight.

• Initial investment and learning curve: Introducing new surveying equipment and software requires some initial cost. However, products like LRTK are more affordable compared to traditional expensive surveying equipment, making it easier to equip one device per person. Although convenient, you will need to become familiar with device operation and data processing at first. It is advisable to have a trial operation period and practice sufficiently before using the equipment for actual work.

• Safety management: Just because work can be completed by one person does not mean safety considerations should be neglected. Always pay attention to the surroundings during surveying and take appropriate safety measures in hazardous locations. Working alone carries the risk that discovery and rescue may be delayed in the event of an accident. Share the work schedule with other staff in advance and keep regular contact to ensure thorough precautions and proceed with safety as the top priority.

• Verification of survey results: Even if one person can perform all tasks, it is important to ensure systems for checking accuracy and preventing mistakes. In multi-person surveys, people could cross-check each other to prevent errors; in one-man surveying, important control points should still be measured and cross-checked by conventional methods if necessary, or have supervisors double-check data on the cloud. Incorporating processes to ensure quality provides reassurance.

Steps to Introduce One-Man Surveying and Success Stories

• Identify needs and create a plan: First, identify where one-man surveying could be used within your company or department. Pick out tasks where relieving manpower shortages is urgent or surveying tasks that occur frequently, and consider the priority for introducing one-man surveying.

• Select and prepare equipment: Next, select appropriate equipment. Prepare a high-precision GNSS device (for example, LRTK) and a compatible smartphone/tablet, as well as any necessary data communication contracts (such as a data SIM). Before purchasing, it is effective to borrow a demo unit or try the actual equipment at an exhibition to confirm usability on site.

• Trial operation and training: Once equipment is ready, conduct a trial operation before deploying it in actual work. Test one-man surveying procedures on company premises or a small site to check data accuracy and operability. It is desirable to practice with not only the responsible person but also other staff so the whole team gains understanding.

• Full implementation and operation: If the trial goes well, integrate one-man surveying into daily operations in earnest. Start with lower-priority tasks and gradually expand the application scope to reduce risk. Also establish rules for data storage and sharing of field-collected data (such as which cloud service to use) to build an environment for smooth operation.

Success stories already exist of organizations that have introduced one-man surveying and achieved results. For example, at a civil engineering construction site that adopted LRTK for single-person surveying, a task that previously required three people and about 20 minutes was completed by one person in approximately 10 minutes. This represented about 50 minutes of labor saved per point, resulting in shortened overall construction time and significant cost reductions. A certain municipality equipped disaster sites with single-person surveying devices and reported that a small team was able to quickly measure and share data for affected locations. In this way, effective use can lead to dramatic efficiency improvements in some cases.

What is LRTK? Technology and Advantages of a Smartphone-Attached RTK System

LRTK is a cutting-edge surveying solution that strongly supports one-man surveying. It is a smartphone-attached RTK-GNSS receiver developed by a startup (Lefixea Inc.) from Tokyo Institute of Technology. Traditionally, RTK-GNSS equipment capable of centimeter-level positioning was very expensive and large, and required operation by specialized operators. However, LRTK is a compact receiver weighing approximately 125 g and only 13 mm thick (0.51 in), and by simply attaching it to a smartphone anyone can easily perform high-precision positioning. It can be attached with one touch to a dedicated smartphone case and has a built-in battery, making it easy to carry.

Technically, LRTK’s high-sensitivity antenna receives signals from multiple satellites (GPS, GLONASS, Galileo, Michibiki, etc.), and the smartphone app combines those signals with correction data obtained from base stations via the internet (or CLAS augmentation signals via satellite) to correct positioning errors in real time. This enables calculation of position coordinates with horizontal and vertical errors on the order of a few centimeters. The smartphone is not just a display terminal but collaborates with the positioning engine to perform necessary computations and coordinate transformations, presenting results to users in an easy-to-understand format.

One of the biggest advantages of using LRTK is its overwhelming ease of use compared to conventional surveying equipment. No special dedicated controller or complex settings are required—just start the app on your everyday smartphone and press a button when you want to measure. Because it can be handled without advanced specialized knowledge, personnel outside a surveying department can autonomously perform quick measurements on site.

In terms of cost, LRTK is also excellent. Whereas in the past a single integrated-antenna high-precision GNSS device could cost several million yen, an LRTK device is available at a far more affordable price. A compact LRTK Phone unit can be purchased for tens of thousands to a few hundred thousand yen, and the dedicated app is provided free of charge. With just a smartphone, you can start high-precision surveying, eliminating the need for expensive dedicated controllers or a permanent base station. The price range makes it feasible for everyone on site to have a unit, overturning the conventional wisdom that surveying equipment must be one set per team.

Furthermore, LRTK is not merely a GNSS receiver; through software integration it provides an all-in-one surveying platform. By combining a dedicated app with cloud services, it seamlessly enables everything from point surveying to data record management, integration with drawings and photos, and sharing. For example, using AR features you can project the positions of structures contained in design drawings onto the site for accurate stakeout, or use a smartphone’s LiDAR scanner to convert terrain or structures into point cloud data and instantly generate 3D survey drawings—advanced tasks that a single person can perform. You can calculate earthwork volumes from acquired point clouds on the spot or compare terrain before and after construction easily. LRTK truly realizes the one-stop concept of "measure, record, share" as a versatile surveying tool.

Conclusion: Start One-Man Surveying with LRTK

In an era of labor shortages, one-man surveying is becoming a trump card for improving efficiency and reducing manpower in surveying tasks. By leveraging the latest technology, a single person can now perform faster and more precise surveying than ever before. Tools like LRTK, introduced in this article, enable a single person to smoothly execute the series of processes—measure, record, share.

Although preparation and practice are required at the start, the barrier is not high. Once you start using it, you will likely feel that "tasks that used to require multiple people have become remarkably easier." This helps reduce on-site burdens and supports workstyle reform, allowing freed personnel to be assigned to other productive tasks.

Surveying and construction personnel considering improved operational efficiency and strengthened accuracy control should positively consider the potential of one-man surveying. Devices such as LRTK continue to evolve and are becoming easier to introduce. As a way to begin, combine advanced surveying tools with your own smartphone and take on new challenges in the field. You will surely be surprised by the convenience and efficiency, and you can become the driver of the next on-site transformation, establishing a smart and productive surveying style.

The LRTK series enables centimeter-level GNSS positioning in construction and civil engineering, significantly reducing work time and improving productivity. It supports the Ministry of Land, Infrastructure, Transport and Tourism’s i-Construction initiative and is an ideal solution for promoting the digitalization of construction sites. For product inquiries, estimates, or consultations about introduction, please feel free to contact us via the following form: https://www.lrtk.lefixea.com/contactlrtk. Take your site to the next stage with LRTK.