The Ace in the Labor Shortage Era: Solo Surveying Enabled by LRTK

Table of Contents

• Why solo surveying is attracting attention: reasons and background

• What is LRTK? A revolutionary device that turns your smartphone into a surveying instrument

• Features of LRTK

• On-site benefits brought by solo surveying

• Simple surveying enabled by LRTK

• FAQ

Why solo surveying is attracting attention: reasons and background

In the construction and civil engineering industries, labor shortages and the aging of skilled technicians have recently become serious issues. With veteran surveyors retiring in succession, it has become increasingly difficult to maintain the traditional system of performing surveying tasks with multiple people. At the same time, job sites demand more accurate survey data than ever before, and a major theme is how to proceed efficiently with limited personnel. Against this backdrop, a new approach that allows small teams—or in the extreme case, a single person to complete surveying tasks—is attracting attention. By leveraging the latest satellite positioning technologies (GNSS/RTK, etc.), even less experienced workers can survey wide areas in a short time while achieving accuracy equal to or better than conventional methods—such possibilities are becoming realistic.

Traditional surveying relied on tape measures, leveling staffs, transits (optical surveying instruments on tripods), and the like, and it was common for at least two people to work together. For example, one person would look through the instrument while another stood at a remote point holding the staff and awaiting instructions, so many tasks depended on manual labor. Surveying large sites or performing staking-out (layout) often required multiple people to work all day. In addition, manual surveying work carries the risk of human error. Misreading or recording mistakes can cause rework in subsequent processes, leading to schedule delays and increased costs.

To address these problems, the entire industry—led by initiatives like the Ministry of Land, Infrastructure, Transport and Tourism’s *i-Construction*—is calling for more efficient and labor-saving surveying. In particular, the style of solo surveying is expected to be a trump card that can simultaneously resolve labor shortages and improve productivity. Within the trend of surveying DX (digital transformation), it is urgent to create an environment where each person can perform high-precision surveying. In fact, expectations for solo surveying are rising not only in construction sites but also in surveying consultancy, agriculture, disaster prevention and mitigation, and infrastructure maintenance and management.

What is LRTK? A revolutionary device that turns your smartphone into a surveying instrument

A key technology that makes this kind of solo surveying possible is LRTK. LRTK is a smartphone-attachable ultra-compact RTK-GNSS receiver developed by a startup originating from the Tokyo Institute of Technology. By simply attaching the dedicated device to a handheld iPhone or iPad, your smartphone instantly becomes a surveying instrument with centimeter-level precision. The device weighs only about 125 g and is pocket-sized with a thickness of about 13 mm (0.51 in), making it easy to carry and attach. It can be attached to a dedicated smartphone case with one touch and set up simply by connecting via Bluetooth or Lightning. Surveying and staking-out work that used to require carrying several-kilogram surveying equipment, setting up tripods, and working in pairs can now be completed by one person with just a smartphone.

By integrating the LRTK device with a smartphone, high-precision positioning using the correction technique called Real-Time Kinematic (RTK) becomes possible. Standard smartphone GPS suffers errors of several meters, but LRTK captures high-precision satellite signals with a dedicated antenna and receives RTK correction data via the network to shrink positioning errors down to a few centimeters. It also supports signals from Japan’s nationwide network of electronic reference points (Ntrip) and the CLAS (centimeter-level augmentation service) broadcast by the Quasi-Zenith Satellite System, so centimeter-level positioning is possible in real time anywhere nationwide as long as there is a communication environment. Even outside of communication coverage, an optional off-coverage antenna kit allows direct reception of CLAS signals from the Quasi-Zenith Satellite, enabling continued high-precision positioning in mountainous areas or disaster sites where mobile signals do not reach.

Features of LRTK

LRTK is designed to make surveying—previously requiring dedicated equipment and personnel—easy for anyone when used together with a smartphone. The main features include the following points.

• Simplicity (portability and quick deployment): The device itself is small and lightweight enough to fit in a pocket. You can quickly take it out, attach it to your smartphone, and start measuring immediately. There is no need to transport heavy equipment or perform complicated setup, offering literally “measure anywhere, anytime.” The convenience of being able to complete surveying and staking-out (layout) on-site single-handedly with just a smartphone is revolutionary.

• Centimeter-level accuracy (cm level accuracy (half-inch accuracy)): LRTK supports RTK and achieves positioning accuracy of approximately ±2–3 cm (±0.8–1.2 in) horizontally and ±3–4 cm (±1.2–1.6 in) vertically. While conventional GPS commonly had errors of 5–10 m, using LRTK reduces errors down to a few centimeters. This accuracy is sufficient for terrain surveys, boundary confirmation, and as-built verification (post-construction shape checks). When satellite reception conditions are good and an RTK fixed solution (Fix) is obtained, even higher stable accuracy such as horizontal ±1–2 cm (±0.4–0.8 in) and vertical ±2–3 cm (±0.8–1.2 in) can be consistently achieved.

• Cloud integration for data sharing: When you measure with the dedicated LRTK smartphone app, the positional coordinates, photos, and notes are immediately uploaded to a cloud map. colleagues in the office can check the latest measurement data in real time via a web browser, smoothing information sharing between the field and the office. Measurement result data can be exported in CSV, PDF, or SIMA formats for use in CAD drawings and reports. Also, by sending a shared URL issued on the cloud to stakeholders, clients and partners can access the data without logging in. Because information measured on-site can be shared and utilized on the spot, the time and effort required for post-survey data organization and notifying stakeholders are greatly reduced.

• Varied measurement and support functions: The LRTK system is not limited to measuring point coordinates; it includes a wealth of features that promote DX on site. For example, by linking with the LiDAR scanner built into iPhone or iPad, you can obtain dense 3D point cloud data simply by walking around for a detailed point cloud scan. Absolute coordinates (latitude, longitude, altitude) are automatically assigned to the acquired point clouds, enabling immediate 3D modeling of terrain and structures for earthwork volume calculations and drafting. There is also a photo positioning function that records the shooting position and orientation simply by taking photos with the smartphone camera. The photos are plotted on the cloud map so you can see at a glance where and in which direction they were taken. Furthermore, an AR (augmented reality) feature allows you to overlay measurement data or design drawing points onto the smartphone camera view. This makes it possible to visualize design positions in the real world, providing guided displays for staking-out positions or overlaying the completed image, enabling intuitive surveying and construction management even when working alone.

On-site benefits brought by solo surveying

By utilizing LRTK in this way, solo surveying becomes fully feasible. This brings significant benefits to how worksites operate. For example, even a young site supervisor, once familiar with the basic operations of LRTK, can perform minor as-built checks and quantity checks without requesting a veteran surveyor. Because anyone can “measure and see results on the spot,” decision-making speed improves dramatically. Moreover, if each person carries an LRTK as a one-per-person surveying tool, they can start measurements whenever needed, enabling rapid responses to design changes and speeding up as-built verification. Reducing unnecessary personnel arrangements and waiting times while ensuring quality and efficiency is the strength of solo surveying. In addition, because all measurement data are digitally recorded and shared, it also helps reduce recording and communication errors—common forms of human error.

Solo surveying with LRTK also offers significant cost advantages. You can avoid purchasing expensive dedicated surveying equipment, thereby keeping initial investment down. LRTK is a subscription-based product consisting of a dedicated device, a smartphone app, and cloud services that are continuously updated and expanded. With continual software updates and support, you can always use the system in optimal condition after deployment. The equipment you bring to the field is drastically reduced, eliminating the need to transport heavy tripods and complex gear, so you can move to any site lightly equipped. Because complicated setup and heavy equipment handling are unnecessary, on-the-job safety also improves. By achieving this labor-saving and light-equipment approach, surveying—previously entrusted to specialists—can become a routine task that “anyone can do,” further accelerating DX at construction sites.

Of course, the knowledge and skills unique to experienced surveyors are not rendered unnecessary. Tasks such as establishing critical control points and interpreting and evaluating data greatly benefit from prior experience. However, LRTK can also serve as a tool for sharing and utilizing experts’ know-how across the entire site. With an interface that is easy for beginners to use and the ability for veterans to share accumulated know-how as digital data, the whole team’s baseline capability improves. The spread of solo surveying means not just reducing manpower but enabling everyone on site to partially take on advanced surveying tasks. This reduces waiting times for surveying that have typically been a bottleneck and streamlines the entire construction cycle.

Simple surveying enabled by LRTK

As described so far, LRTK is equipped with advanced surveying and measurement functions yet is designed to be very easy to use. In other words, LRTK has ushered in the era of “simple surveying.” Anyone with a smartphone in hand can measure site conditions, immediately share data, and use it for the next actions—surveying, once reserved for specialists, is becoming part of routine on-site work with the advent of LRTK.

For example, even staff with limited field experience can complete minor surveys and as-built checks on their own once they get used to operating LRTK. Realizing “measure and know on the spot” without relying on veterans dramatically increases site responsiveness. Eliminating the effort to carry heavy equipment improves safety, and staff with reduced burdens can devote time to higher value-added tasks. Indeed, simple surveying with LRTK is becoming a new standard that boosts on-site productivity.

From a cost perspective as well, LRTK brings major advantages over traditional surveying styles. There is no need to stock multiple dedicated instruments or spend heavily on labor; a smartphone and a small device per person suffice, significantly reducing initial deployment and operating costs. Because the subscription model ensures continuous software updates, once introduced you can continuously enjoy the latest features—an economic benefit. Miniaturization of equipment also makes movement lighter, allowing flexible対応 to any site with agility—a major strength for the future. That surveying has been simplified to this extent undeniably contributes to industry-wide digitalization and efficiency improvements.

From beginners to professionals, LRTK provides value according to the user’s level and application. It is simple and intuitive for first-time users and a reliable partner that dramatically enhances efficiency and accuracy for experienced practitioners. Please consider adopting LRTK Phone on your sites and experience a surveying workflow that overturns conventional wisdom. From now on, let simple surveying with LRTK open up the future of on-site operations.

FAQ

Q. What kinds of surveying and measurement tasks are possible with LRTK? A. LRTK can handle various surveying and measurement tasks required on-site. For example, it supports accurate point coordinate measurement (single-point positioning), 3D point cloud measurement and photo positioning using the smartphone’s LiDAR and camera, support for staking-out (layout) based on design drawings, and AR overlay display for as-built image superposition, covering a wide range of uses with a single device. It also has functions to calculate distances, areas, and volumes from acquired data, enabling tasks that previously required separate instruments or multiple people to be completed by one person with only LRTK.

Q. Which smartphones are compatible with LRTK? A. Currently, LRTK (LRTK Phone) supports Apple iPhone and iPad (iOS devices). A dedicated mounting case is provided for iPhone use, and when using an iPad, a separate holder is used to secure it. Unfortunately, Android devices are not supported at this time.

Q. Can high-precision positioning be performed in mountainous areas where there is no mobile coverage? A. Yes. Normally, network-type RTK services (such as Ntrip) via the smartphone’s data connection are used to receive correction information, but even in areas without mobile signals, high-precision positioning is possible using the off-coverage kit (CLAS-compatible antenna). The LRTK device can directly receive the centimeter-level augmentation service (CLAS) signals broadcast by Japan’s Quasi-Zenith Satellite “Michibiki” and use them for real-time corrections, maintaining centimeter-level positioning accuracy in mountainous regions, remote islands, or disaster sites where communications are unreliable. However, because it is necessary to receive signals from satellites, having an open sky (clear line of sight) is a condition.

Q. How accurate is the positioning in practice? A. When environmental conditions are favorable and RTK functions properly, a typical accuracy guideline is horizontal ±1–2 cm (±0.4–0.8 in) and vertical ±2–3 cm (±0.8–1.2 in). Considering that standalone smartphone GPS previously had errors of several meters, this is a dramatic improvement. However, accuracy varies with satellite signal reception conditions. In urban areas with tall buildings or locations with many trees, accuracy may temporarily decrease, but moving to an open area or waiting for some time generally restores high accuracy. The LRTK app also includes an averaging positioning function that averages multiple measurements to improve accuracy. When measuring important control points, using this function and averaging dozens of measurement samples can stably achieve millimeter-level accuracy.

Q. How long does the internal battery last? A. The LRTK device runs on a rechargeable battery and provides continuous use for about 6 hours on a full charge (may vary depending on usage conditions and temperature). For long surveys, it can be used while being charged by a mobile battery. Charging is done via the included USB Type-C cable and can be powered by a general USB power adapter. The device is splash-resistant (equivalent to IPX3), so minor rain is unlikely to cause failure; however, avoid using it in heavy rain or charging it while wet, and ensure proper drying and maintenance. In normal field environments, the battery life is sufficient for worry-free use.

Q. Can I operate it without surveying expertise? A. Yes. LRTK is designed to be intuitive to operate even without specialized knowledge. For basic point recording, you simply follow the on-screen prompts and press buttons, so you can achieve high-precision measurements without understanding complicated theory. Single-point positioning and photo-attached survey records are especially straightforward for anyone familiar with smartphone apps. Advanced functions such as point cloud scans and AR-based layout are also guided step by step by the app, providing reassurance. However, interpreting and applying the acquired data (for example, comparing with drawings to verify as-built conditions) can benefit from conventional surveying experience and knowledge. Start with basic functions and gradually challenge advanced features to build proficiency comfortably. LRTK is a tool you learn by using, and the more you use it, the more you will feel its reliability on-site. Please don’t hesitate to apply it in the field.