RTK Receiver — Rental-Free On-Site Digital Transformation: Streamline Point Cloud and Photo Recording with an Annual LRTK Subscription

Table of Contents

• How Field DX Is Changing Surveying Norms

• Challenges of the Conventional Method of Renting RTK Receivers

• What Is LRTK, the New Surveying Method That Can Be Completed with a Smartphone?

• Streamlining Point Cloud Measurement and Photo Recording with LRTK

• Cost Reduction through Implementation and Benefits Across Various Fields

• Towards the Future of On-site Surveying DX

• Frequently Asked Questions (FAQ)

How On-site DX Is Changing Surveying Norms

In recent years, the wave of digital transformation (DX) has been rapidly spreading across the construction industry and surveying sites. Especially in on-site positioning technologies, new methods that utilize smartphones, CAD, and the cloud are attracting attention. As exemplified by policies such as i-Construction (ai-Construction) advocated by the Ministry of Land, Infrastructure, Transport and Tourism, on-site reforms leveraging ICT and smart devices are being advanced by many companies. Tasks that traditionally relied on specialized surveying equipment and manpower have been streamlined through the introduction of digital technologies, and an era has arrived in which even a single person can easily achieve centimeter-level accuracy (half-inch accuracy). As on-site DX (the digitalization of worksites) progresses, the conventional notion of “renting an RTK receiver to conduct surveys” is also beginning to be reexamined. 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, we introduce the benefits of adopting LRTK under an annual contract—such as streamlining everything from point-cloud measurement to photo documentation—and explore how this form of on-site DX can lead to cost reductions and operational improvements.

Challenges of the traditional method of renting RTK receivers

Traditionally, achieving centimeter-level positioning and surveying required the use of expensive RTK-GNSS receivers (positioning devices). Because purchasing the equipment would require an investment on the order of several million yen, companies often rent the equipment only when needed or outsource to specialized surveying firms. However, there are several issues with these traditional methods.

• Cost and logistical burden: High-precision GNSS equipment has very high acquisition costs, and even when renting or outsourcing there is a fee each time. At sites that require frequent surveying, rental fees accumulate and the cost burden becomes significant. In addition, pre-arrangements such as booking equipment loans and coordinating handovers were time-consuming.

• Heavy operational burden: Traditional surveying often required multiple people to set up and operate the equipment, with site personnel and surveying specialists working together. Tasks such as carrying and setting up heavy tripods and receivers, and shuttling data between the field and the office, demanded considerable time and manpower.

• Dependence on skilled personnel: Operating RTK positioning equipment requires specialized knowledge and experience, and there were many situations where it was necessary to rely on experienced surveyors. Because tasks like configuring equipment, securing reference points, and interpreting positioning results depended on specific skills, there was a risk of work stalling when personnel were scarce.

• Data management and accuracy risks: Manual workflows—such as jotting coordinate data in notebooks and later entering it into a PC to create CAD drawings—inevitably carried the possibility of human error. Copying mistakes or input errors could cause shifts in survey points and drawing inaccuracies. Also, because results could not be checked on site, inefficiencies arose from discovering errors or missing data later and having to re-measure.

• Lack of real-time capability: It was also an issue that it was difficult to instantly share surveying data obtained on site with stakeholders or to reflect it in design data. Because data processing and drafting take time, even if conditions on site changed, it was not possible to respond in real time, resulting in time lags.

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

What is the new smartphone-based surveying "LRTK"?

A technology called smartphone RTK, which has appeared in recent years, is beginning to greatly change the conventions of surveying. Smartphone RTK combines a smartphone with a compact, high-precision GNSS receiver and uses the real-time kinematic (RTK) method to achieve centimeter-level positioning (cm; inch-level accuracy). Normally, standalone GPS positioning on smartphones results in errors of about 5-10 m (16.4-32.8 ft), but RTK uses correction information from separately installed reference stations or sent from satellites to cancel out those errors, allowing positions to be determined with errors of only a few centimeters (a few inches).

The advantage of smartphone RTK is that it can replace the conventional, stationary, and bulky GNSS surveying instruments with a pocket-sized solution. Because it achieves accuracy comparable to expensive, large dedicated equipment using a smartphone plus a receiver that fits in the palm of your hand, on-site handling is dramatically improved. In addition, the smartphone app automatically calculates and saves positioning results and allows visual confirmation on a map, providing user-friendly operation. Specialized coordinate transformations are also handled automatically by the app, so you can use surveying results as-is without advanced knowledge. Smartphone RTK, which enables "centimeter accuracy for anyone, anywhere" positioning, is truly an innovative technology that supports on-site DX.

One concrete solution for realizing smartphone RTK is LRTK. LRTK is an integrated surveying system composed of a compact GNSS receiver device that attaches to smartphones such as the iPhone, a dedicated app, and cloud services. Weighing approximately 165 g and about 1 cm (0.4 in) thick, it is a smartphone-sized surveying instrument that achieves high-precision positioning of about ±1-2 cm (±0.4-0.8 in) that cannot be obtained with standalone positioning. By attaching the LRTK device to a smartphone and launching the app in an environment with a clear view of the sky, it corrects satellite positioning data in real time to determine the location. In Japan, it supports the Geospatial Information Authority of Japan's electronic reference point network and the centimeter-level positioning augmentation service (CLAS) provided by the Quasi-Zenith Satellite System “Michibiki” (QZSS), enabling high-precision positioning even in mountainous areas or disaster sites where mobile signals are unavailable. In actual verifications, coordinates obtained with LRTK have been confirmed to differ little from results measured with Class-1 GNSS equipment costing several million yen. Despite that level of accuracy, a major feature of LRTK is that it does not require special qualifications or personnel to use, and allows a single person to complete surveying work easily.

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 the various records and measurements required on site with a single unit. With an annual subscription to LRTK, you can fully utilize the functions below to streamline the entire workflow—from acquiring point cloud data to photo documentation and drawing support.

• High-precision positioning records: Coordinates (latitude, longitude, height) of points obtained by GNSS positioning are recorded with cm level accuracy (half-inch accuracy). Survey points are displayed on the map in real time, allowing immediate position confirmation on site.

• 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 one button using LRTK.

• AR display of design data: Leveraging positioning accuracy, pre-prepared design models (BIM/CIM data, etc.) can be displayed in the real-world site via AR. With no alignment offset, you can precisely overlay the planned drawings onto the actual site, aiding as-built verification and preventing construction errors.

• Geotagged photo function: When you take photos with your smartphone camera, the coordinates of the shooting position and the camera’s orientation (azimuth) are automatically recorded. Because the photos accurately record when, where, and in which direction they were taken, you can reliably manage photos for construction records and inspection reports.

• Coordinate navigation (staking support): Enter coordinate values from design drawings or previous surveys as target points and navigation starts on the smartphone screen. By following arrows and distance indicators, you can perform staking—placing markers on the ground—alone. Tasks that traditionally required multiple people can be completed quickly and solo with LRTK.

• Cloud integration and data sharing: Survey points, tracks, photos, and point cloud data obtained with LRTK can be synced to the cloud from the site with one tap. Office PCs can instantly view site data via a browser, and measure distance, area, and volume or overlay drawing files. Because 3D data can be handled without installing software, information is seamlessly shared between site and office and report preparation becomes speedy.

In this way, by using LRTK the functions required for surveying and recording are all provided in one, eliminating the need to switch between multiple devices and tools. If you keep LRTK on site with an annual subscription, you can immediately perform high‑precision measurement and recording yourself when needed, so you will be freed from rental wait times and cumbersome data management.

Cost reductions from implementation and benefits in each sector

The effects expected from introducing LRTK are not limited to just improved surveying accuracy and work efficiency. By promoting on-site DX, significant benefits such as cost reduction and improvement of business workflows can be realized. Here, we outline the points that are particularly effective from the perspectives of construction companies, surveying companies, and local governments.

Construction company site staff: You will be able to perform the necessary surveying and as-built management with your own staff, without renting surveying equipment or relying on external surveying teams. For example, you can perform height checks before foundation work and as-built inspections on the spot with LRTK, and if you share the data to the cloud immediately, it will reduce waiting times and prevent rework. Because one person can grasp the current site conditions alone, there is no need to adjust personnel assignments, enabling rapid on-site decision-making.

Surveying contractors: It becomes easier to cover multiple sites with a small team, improving operational mobility. If you carry LRTK, surveys that previously required lengthy preparation can be handled immediately, shortening lead times for requests. You can also offer new services using point cloud data and AR, proposing high-value deliverables to clients beyond traditional plans and numerical data. Since it can be operated more cost-effectively than renting high-precision equipment each time, it also contributes to improved profit margins.

Municipal infrastructure departments: Even for infrastructure maintenance such as roads and rivers, LRTK enables rapid on-site inspection and recording. For example, if the person in charge measures and photographs damage immediately after a disaster and uploads it to the cloud, information can be shared in real time with supervisors and other departments in the office. By reducing reliance on external contractors while making decisions based on accurate data, you achieve both budget savings and faster operations. An LRTK that can obtain positioning via satellite augmentation even in mountainous areas without radio reception will be a reliable tool for any site.

By leveraging an annual LRTK subscription in this way, you can achieve better cost performance and operational efficiency across various fields than before. Having measurement tools readily available in-house when you need them may be considered a new kind of "on-site capability" for the coming era.

Toward the Future of DX at Surveying Sites

The conventional practice of renting an RTK receiver for every 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, allowing anyone to obtain high-precision data whenever they need it. 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.

While LRTK is equipped with advanced functions such as point cloud measurement, photographic recording, and AR visualization, its operation is simple and designed so that even first-time users can handle it intuitively. As a key to promoting on-site DX, LRTK has the potential to become the future standard. If you are spending time and costs on renting surveying equipment and on complicated adjustments as before, why not take this opportunity to consider simple surveying with LRTK. Adopt an easy-to-use, high-accuracy measurement tool to achieve productivity gains and cost reductions through on-site DX. LRTK also offers demos and trials before deployment, so it may be a good idea to start by trying it out on a small-scale site.

Frequently Asked Questions (FAQ)

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

Q. Are there any accuracy differences compared with conventional RTK receivers? A. In terms of accuracy, LRTK is capable of centimeter-level positioning comparable to conventional professional RTK-GNSS receivers. In actual comparative tests, it has recorded positions with accuracy almost indistinguishable from high-end GNSS equipment. However, depending on the surrounding environment (satellite visibility and radio signal conditions), positioning may sometimes take longer.

Q. Do I need any special qualifications or knowledge to use it? A. No. LRTK is designed to be used without being a professional surveyor. By following the instructions in the app, even first-time users can intuitively perform positioning and point cloud scanning. Complex settings, such as coordinate system conversions, are automated, so you don’t need surveying expertise.

Q. In what situations is LRTK useful? A. It is useful not only for surveying work in construction and civil engineering, but also in a wide range of situations such as infrastructure inspections, disaster surveys, and understanding current conditions for urban planning. For example, applications include as-built measurements for road works, inspection and maintenance surveys of bridges and tunnels, land acquisition surveys and confirmation of land boundaries, topographic surveys in forestry, and even field measurements in agricultural civil engineering. Because it can quickly obtain accurate positional information and records on site, it is expected to be a tool that promotes DX in any field where “measuring” work is required.

Q. Is a network connection required for surveying? A. LRTK can receive correction information from a reference station via the Internet, but within Japan it is also possible to perform positioning without cellular coverage by using augmentation signals (CLAS) from the Quasi‑Zenith Satellite "Michibiki". Therefore, you can maintain high-precision positioning even at sites such as mountainous areas where cellular signals do not reach. However, when synchronizing or sharing data to the cloud, you will need to upload it later from a location with network connectivity.

Q. Can it be used with any smartphone? A. The LRTK app currently supports iOS, and you can take full advantage of its features especially on iPhones equipped with a LiDAR sensor (iPhone 12 Pro and later models). Models without LiDAR can still use positioning and regular photo-recording features, but the accuracy of the 3D point cloud scanning feature is higher on LiDAR-equipped devices. For future supported OSes and requirements, please check the product website for the latest information.

Q. Is there a format for measurement data and compatibility with other systems? A. Data acquired with LRTK can be output and shared in common formats. For example, point cloud data can be exported in LAS or XYZ formats, surveyed point coordinate lists in CSV format, and photos as geotagged JPEG files. LRTK Cloud also provides features to generate DXF drawings and to import and overlay existing CAD data. Because data compatibility with other CAD software and GIS systems is high, it can be smoothly integrated into existing workflows after implementation.

Q. How can I implement LRTK? A. LRTK is offered as an annual subscription service. When you subscribe, it includes either a loaned GNSS receiver device or a purchase plan, plus access 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 application methods and provide demonstrations tailored to the challenges at your site.