RTK Receivers — Rental-Free On-Site DX: Streamline Point Cloud and Photo Recording with an Annual LRTK Contract

Table of Contents

• How Field DX Is Changing Surveying Conventions

• Challenges of the Traditional Method of Renting RTK Receivers

• What Is the New Smartphone-Based Surveying "LRTK"?

• Streamlining Point Cloud Measurement and Photo Documentation with LRTK

• Cost Savings from Implementation and Benefits Across Various Fields

• Towards the Future of Field DX in Surveying

• Frequently Asked Questions (FAQ)

How On-site DX Is Changing Surveying Conventions

In recent years, the wave of digital transformation (DX) has rapidly spread across the construction industry and surveying sites. In particular, new approaches to on-site positioning—leveraging smartphones, CAD, and cloud services—are attracting attention. As symbolized by policies such as i-Construction（アイ・コンストラクション）proposed by the Ministry of Land, Infrastructure, Transport and Tourism, companies are advancing on-site reforms that utilize ICT and smart devices. Tasks that traditionally relied on specialized surveying instruments and manpower have been streamlined by the introduction of digital technologies, and an era has arrived in which even one person can easily achieve centimeter-level accuracy. As on-site DX (the digitalization of worksites) progresses, the conventional wisdom of “renting an RTK receiver to perform surveying” is beginning to be reconsidered. In this article, taking into account the challenges of conventional methods, we explain the technology for high-precision positioning using smartphones and a new solution called LRTK that realizes it. Furthermore, by adopting LRTK under an annual subscription, we introduce the advantages of being able to streamline everything from point cloud measurement to photographic records, and explore how on-site DX can lead to cost reduction and operational improvements.

Challenges of the conventional approach to renting RTK receivers

Traditionally, performing centimeter-level positioning and surveying required the use of expensive RTK-GNSS receivers (positioning devices). Because purchasing the equipment in-house can require an investment on the order of several million yen, it is not uncommon to rent equipment only when needed or to hire specialized surveying companies. However, there are several challenges with these conventional methods.

• Cost and logistical burden: High-precision GNSS equipment has very high acquisition costs, and renting or outsourcing also incurs expenses each time. On sites that require frequent surveying, rental fees accumulate and create a heavy cost burden. In addition, advance arrangements such as booking equipment loans and coordinating pick-up and drop-off were time-consuming.

• Heavy workload: Conventional surveying often required multiple people to set up and operate equipment, with site staff and surveying specialists working together. Carrying and installing heavy tripods and receivers, and shuttling between the site and the office to transfer data, were time- and labor-intensive tasks.

• Dependence on skilled personnel: Operating RTK positioning equipment requires specialized knowledge and experience, and there were many cases where reliance on experienced surveyors was unavoidable. Because tasks such as device configuration, securing reference points, and interpreting positioning results depend on specific skills, there was a risk of work delays during personnel shortages.

• Data management and accuracy risks: Manually recording coordinate data in notebooks and later entering it into a computer to create CAD drawings inherently introduces the possibility of human error. Transcription mistakes or input errors could cause point shifts or drawing inaccuracies. Also, because measurement results could not be checked on the spot, inefficiencies arose when errors or insufficient data were discovered later and required re-measurement.

• Lack of real-time capability: It was also difficult to instantly share survey data obtained on site with stakeholders or reflect it in design data. Because data processing and drafting take time, even if conditions change on site, teams cannot respond in real time, resulting in time lags.

Thus, the conventional "rental equipment plus manual surveying" approach is costly and inefficient, and is increasingly ill-suited to the current on-site needs that demand DX. So, what kinds of technologies are emerging as solutions?

What Is LRTK, the New Surveying Method Completed on a Smartphone

A technology known as smartphone RTK, which has emerged in recent years, is beginning to significantly change conventional surveying. Smartphone RTK combines a smartphone with a compact, high-precision GNSS receiver and uses a method called real-time kinematic (RTK) to achieve centimeter-level positioning. Normally, standalone GPS positioning on a smartphone produces errors of about 5–10 meters, but RTK uses correction information from a separately installed base station or sent from satellites to cancel out those errors, enabling positions to be pinpointed to within a few centimeters of error.

The advantage of smartphone RTK is that it can replace the conventionally fixed, large-scale GNSS surveying equipment with a pocket-sized device. Because it can achieve accuracy comparable to expensive, large dedicated instruments using a smartphone plus a receiver that fits in the palm of your hand, on-site handling is dramatically improved. In addition, positioning results are automatically calculated and saved by smartphone apps and can be visually confirmed on maps, making for user-friendly operation. Specialized coordinate transformations are also processed automatically by the app, so surveying results can be used as-is even without advanced knowledge. Smartphone RTK, which enables "centimeter accuracy for anyone, anywhere," is truly an innovative technology that supports on-site digital transformation.

One concrete solution that realizes this smartphone RTK is LRTK. LRTK is an integrated surveying system consisting of a compact GNSS receiver device that attaches to smartphones such as the iPhone, a dedicated app, and cloud services. As a smartphone-sized surveying instrument weighing about 165 g and roughly 1 cm thick, it achieves high-precision positioning of approximately ±1–2 cm that cannot be obtained by standalone positioning. If you attach the LRTK device to your smartphone and launch the app in an environment with a clear view of the sky, it corrects satellite positioning data in real time to determine position. Within Japan, it also supports the Geospatial Information Authority of Japan’s network of Electronic Reference Points and the centimeter-level augmentation service (CLAS) provided by the Quasi-Zenith Satellite “Michibiki” (QZSS), enabling high-precision positioning even in mountainous areas without cellular coverage or at disaster sites. Actual validation has confirmed that coordinates obtained with LRTK differ hardly at all from measurements made with first-class GNSS equipment costing several million yen. Despite that level of accuracy, LRTK does not require special qualifications or personnel to use, and its major feature is that a single person can easily complete surveying work.

Streamline Point Cloud Measurement and Photo Documentation with LRTK

LRTK not only acquires high-precision positional information, but is also a versatile tool that can handle various on-site records and measurements with a single device. By adopting LRTK on an annual subscription, you can fully utilize the features below to streamline the entire process—from acquiring point cloud data to photo documentation and drafting support.

• High-precision positioning records: Coordinates of points obtained by GNSS positioning (latitude, longitude, altitude) are recorded with centimeter accuracy. Measured points are displayed on the map in real time, allowing you to confirm positions on the spot.

• 3D point cloud scanning: By combining the iPhone’s built-in LiDAR sensor and camera, the surrounding environment is rapidly scanned as three-dimensional point cloud data. The acquired point cloud is assigned global coordinates, so each point contains actual measured position information. Detailed 3D records that previously required dedicated 3D scanners or photogrammetry software can be completed with a single button using LRTK.

• Design data display via AR: Leveraging positioning accuracy, pre-prepared design models (BIM/CIM data, etc.) can be displayed in AR within the real-world site. With no misalignment in positioning, planned drawings can be accurately overlaid onto the site conditions, aiding as-built verification and preventing construction errors.

• Positioned photo function: When you take a photo with your smartphone camera, the shooting position’s coordinates and the camera’s orientation (bearing) are automatically recorded. Because it precisely records when, where, and in which direction a photo was taken, you can manage photos with high reliability for construction records and inspection reports.

• Coordinate navigation (stake-out support): If you input coordinate values from design drawings or past surveys as target points, navigation begins on the smartphone screen. By following arrows and distance indicators, you can move to the target and perform stake-out work alone. Positioning tasks that used to require multiple people can be completed solo and in a short time with LRTK.

• Cloud integration and data sharing: Measured points, tracks, photos, and point cloud data acquired with LRTK can be synced to the cloud from the field with a single tap. From an office PC you can instantly view field data via a browser and perform distance, area, and volume measurements or overlay drawing files. Because 3D data can be handled without installing software, information is shared seamlessly between the field and the office, speeding up the preparation of reports.

In this way, using LRTK provides all the functions required for surveying and recording in an all-in-one solution, eliminating the hassle of juggling multiple devices and tools. If you keep LRTK on-site under an annual contract, you can perform high-precision measurements and recordings yourself immediately when needed, freeing you from time spent waiting for rentals and cumbersome data management.

Cost Savings from Implementation and Benefits Across Sectors

The effects expected from implementing LRTK are not limited to improvements in surveying accuracy and work efficiency. By promoting on-site DX, significant benefits such as cost reduction and improvements in operational workflows can be realized. Here, we outline the points that are particularly effective from the perspectives of construction companies, surveying firms, and municipalities.

• Construction company site personnel: They will be able to perform the necessary surveying and as-built management with their own staff, without renting surveying equipment or relying on external survey teams. For example, height checks before foundation work and as-built inspections can be performed instantly with LRTK, and if the data is shared to the cloud on site, it can reduce construction waiting times and prevent rework. Because one person can grasp the current conditions alone, there is no need to adjust manpower deployment, enabling faster decision-making on site.

• Surveying firms: It becomes easier to cover multiple sites with a small team, improving mobility. Carrying LRTK allows survey tasks that previously required lengthy preparation to be addressed immediately, shortening lead times for requests. In addition, new services using point cloud data and AR become possible, enabling the proposal of high-value deliverables to clients beyond traditional plans and numerical data. It can be operated more cost-efficiently than renting high-precision equipment each time, contributing to improved profit margins.

• Municipal infrastructure departments: For infrastructure maintenance and management such as roads and rivers, LRTK enables rapid on-site inspection and recording. For example, if staff measure and photograph damage immediately after a disaster and upload it to the cloud, information can be shared in real time with supervisors in the office and other departments. Reducing reliance on external contractors while enabling decisions based on accurate data delivers both budget savings and faster operations. With LRTK that can provide positioning even in mountainous areas where radio signals do not reach by augmenting with satellite support, it becomes a reliable tool for any site.

By leveraging LRTK's annual contract in this way, you can achieve superior cost performance and operational efficiency across each field. Equipping your company with measurement tools that are ready to use whenever needed may be considered the new "on-site capability" for the coming era.

Toward the Future of On-Site Surveying DX

The previous practice of renting an RTK receiver for each job is entering a major turning point with the arrival of the DX era. By introducing smartphone-integrated high-precision positioning tools like LRTK, surveying work can be dramatically simplified, and anyone can obtain high-precision data whenever needed. Without relying on heavy, complex equipment or specialist contractors, field personnel themselves can perform simple surveying with a single smartphone and share information in real time via the cloud — this new form of on-site DX is becoming a reality.

LRTK combines advanced functions such as point cloud measurement, photographic documentation, and AR visualization while remaining simple to operate and designed to be intuitive even for first-time users. As a key to promoting DX at worksites, LRTK has the potential to become the future standard. If you have been spending time and money renting surveying equipment and dealing with complicated setups as before, why not consider simple surveying with LRTK? Equip yourself with an easy-to-use, highly accurate measurement tool to achieve productivity improvements and cost reductions through on-site DX. LRTK also offers demo experiences and trials before deployment, so it may be a good idea to start by testing it at a small site.

Frequently Asked Questions (FAQ)

Q. What is LRTK? A. LRTK is a high-precision positioning system that is attached to a smartphone (primarily iPhone) for use. By combining a compact GNSS receiver device, a dedicated app, and cloud services, it enables centimeter-level positioning, 3D scanning, and photo location recording all with a single device.

Q. Is there a difference in accuracy compared to conventional RTK receivers? A. In terms of accuracy, LRTK can achieve centimeter-level positioning comparable to conventional professional RTK-GNSS receivers. In real-world comparison tests, it has recorded positions with accuracy nearly indistinguishable from high-end GNSS equipment. However, depending on the surrounding environment (satellite visibility and radio signal conditions), it may take longer to obtain a fix.

Q. Do I need any special qualifications or knowledge to use it? A. No. LRTK is designed to be usable even by people who are not professional surveyors. By following the in-app guidance, even first-time users can intuitively perform positioning and point cloud scanning. Difficult settings, such as coordinate system conversions, are automated, so you do not need surveying expertise.

Q. In what situations does LRTK excel? A. LRTK is useful in a wide range of situations—not only for surveying work in construction and civil engineering, but also for infrastructure inspections, disaster surveys, and grasping current conditions for urban planning. For example, it has diverse applications such as as-built measurements for roadworks, maintenance inspections of bridges and tunnels, land-acquisition surveys and boundary verification, topographic surveys in forestry, and field measurements in agricultural civil engineering. Because it enables rapid and accurate on-site acquisition of positional information and records, it is expected to be a tool that promotes DX in any field that requires "measuring" work.

Q. Do you need a network connection for surveying? A. LRTK can receive correction information from base stations via the internet, but within Japan you can also perform positioning outside mobile coverage by using the Quasi-Zenith Satellite "Michibiki" augmentation signal (CLAS). Therefore, high-precision positioning can be maintained even at sites where cellular signals do not reach, such as mountainous areas. However, when synchronizing or sharing data to the cloud, you will need to upload it later from a location with network access.

Q. Can it be used with any smartphone? A. Currently the LRTK app supports iOS, and you can make full use of its features particularly on iPhones equipped with a LiDAR sensor (iPhone 12 Pro and later models). Models without LiDAR can still use positioning and regular photo recording functions, but the accuracy of the 3D point cloud scanning function is higher on LiDAR-equipped devices. For future supported OS versions and requirements, please check the product site's latest information.

Q. Are there standard formats for measurement data, and is it compatible with other systems? A. Data acquired with LRTK can be exported and shared in standard formats. For example, point cloud data can be exported in LAS or XYZ formats, lists of measured point coordinates in CSV format, and photos as JPEG files with embedded location information. LRTK Cloud also provides functions to generate DXF drawings and to import and overlay existing CAD data. Because it offers high data compatibility with other CAD software and GIS systems, it can be smoothly integrated into your existing workflows after implementation.

Q. How do I implement LRTK? A. LRTK is offered as an annual subscription service. When you sign a contract, it includes the loan of GNSS receiver devices or a purchase plan, along with access rights to the dedicated app and cloud. If you are considering adoption, please feel free to contact us via the inquiry form on the official website. We can also discuss usage methods tailored to your on-site challenges and provide demonstrations.