The Future of Surveying Opened by RTK AR – Precision Positioning by AR Guidance Becomes the New Standard

Table of Contents

• Introduction

• What Is RTK AR?

• Benefits of AR-Guided Surveying

• Use Cases of AR-Guided Surveying

• Challenges and Countermeasures for Implementation

• The Future of Surveying Opened by RTK AR

• Simplified Surveying with LRTK

• FAQ

Introduction

In recent years, a new keyword—RTK AR—has been attracting attention in surveying and construction fields. RTK stands for the high-precision satellite positioning technology Real Time Kinematic, and AR stands for Augmented Reality. By combining these two, the RTK×AR technology is realizing a revolutionary surveying style that overturns conventional wisdom. In traditional surveying, experienced personnel would operate equipment as a team, performing layout work and staking on site. However, due to labor shortages caused by an aging population and workstyle reforms, methods that allow rapid and accurate surveying by a single person are being sought. Enter the fusion of RTK and AR—so-called AR-guided surveying. This article, under the theme “The Future of Surveying Opened by RTK AR,” explains in detail the mechanisms and benefits of high-precision positioning with AR guidance, practical use cases, and points to note when introducing the technology. At the end, we also introduce LRTK, a solution that lets you easily experience this new technology.

What Is RTK AR?

First, what does RTK AR mean? Simply put, it is a surveying method that combines high-precision GNSS positioning (RTK) with augmented reality (AR). RTK enables smartphones and tablets to obtain positions with centimeter-level accuracy (cm level accuracy, half-inch accuracy), and that position information is used to overlay 3D models and guide markers onto the real world (AR display). This makes it possible to work on site while visually confirming design drawings and measurement points. Specifically, a small RTK-capable GNSS receiver is attached to a smartphone or similar device, and by using RTK correction information (for example, data via a network RTK service), the device’s high-precision position is calculated in real time. At the same time, the AR app overlays virtual lines, points, and models onto the camera view to intuitively indicate the points to be measured or the locations to be installed. In other words, RTK AR solves the conventional AR problem of large GPS errors causing misalignment by using RTK’s high-precision positioning, thereby seamlessly fusing the virtual and the real. With this technology, field personnel can simply follow the on-screen guidance to accurately reach points shown on the drawings. When they arrive at a point to be measured, they hold up the smartphone, judge where the virtual marker on the screen corresponds in the field, and perform the necessary measurements or markings. Conversely, points measured on site can be immediately displayed in the AR space for cross-checking with design data. RTK AR, therefore, can be regarded as a next-generation surveying solution that combines centimeter-level position information and visual AR navigation.

Benefits of AR-Guided Surveying

AR-guided surveying using RTK AR technology offers many advantages over conventional methods. Here are the main benefits.

• Surveying with fewer people and in less time: Tasks that previously required a multi-person team and long hours with transit or GPS surveying can be completed by one person in a short time with RTK AR. Because high-precision GNSS simultaneously provides position measurement and target guidance, work efficiency dramatically improves.

• Intuitive and easy operation: The visual guidance provided by AR allows staff with limited specialized knowledge to intuitively find points and operate equipment. The burden of complex coordinate calculations and drawing interpretation is reduced, making surveying accessible to anyone.

• Immediate verification and sharing: Measurement results on site can be displayed in AR and compared with the design model for instant verification. By sharing photos or point cloud data to the cloud, stakeholders in remote locations can receive information in real time, enabling faster decision-making.

• Cost reduction: Compared to procuring specialized surveying equipment (expensive GNSS receivers or total stations), a configuration of a smartphone plus a small RTK receiver may lower initial investment in some cases. Rather than renting multiple devices or incurring high labor costs, one-person-one-smartphone surveying could allow operations to be carried out more economically.

• Improved safety: AR guidance enables indicating points or measuring from a safe distance in hazardous locations, allowing non-contact measurement and contributing to worker safety. It reduces the need for awkward positions at heights or on unstable footing, leading to reduced accident risk.

Use Cases of AR-Guided Surveying

So, in what scenes is RTK AR technology actually useful? Here are several concrete use cases of AR-guided surveying.

• Efficient single-person staking and layout: Traditionally, survey teams would walk the site to drive wooden stakes or mark lines. With RTK AR, virtual stakes and markers for reference points or boundary lines on the design can be displayed in AR. The worker simply moves to the point while looking at the smartphone screen and marks the exact location. In narrow areas or on slopes, you can avoid physically driving stakes, enabling fast single-person layout work.

• Overlaying design models in AR: 3D design models created with BIM/CIM can be overlaid on the site view. For example, by AR-displaying the completed shape of road embankments or structures, you can intuitively convey the final image to operators, construction crews, clients, and nearby residents. This helps prevent misunderstandings and reduces rework.

• Application to as-built and quality control: For as-built control, design cross-sections can be overlaid on the terrain in AR to compare the current ground shape with the planned lines. Differences between measured point cloud data and the design model can be visualized on site, making it possible to instantly grasp excesses or deficiencies in fill and cut. During inspections, AR can display markers for checkpoints to prevent oversights, and for fixed-point observations AR can guide the same camera position as before to record temporal changes easily.

• Point cloud scanning and volume calculation: RTK AR is also powerful when performing point cloud scans on LiDAR-equipped smartphones. Simple smartphone scans are often distorted due to ambiguous positioning, but assigning absolute coordinates to the acquired point cloud with RTK produces point clouds of sufficient accuracy for as-built measurement that can be acquired immediately. By measuring terrain before and after excavation and calculating differences on site, volume management—such as fill volume and spoil volume—can be easily performed by specifying the area according to AR guidance.

• Disaster response and remote support: In disaster zones where heavy machinery cannot enter, manual surveying is sometimes necessary. Even in such situations, a smartphone and a high-precision GNSS device can quickly measure local terrain and damage, and share it immediately via the cloud with office engineers. In Japan, some local governments have used iPhones with high-precision GNSS devices for disaster recovery, maintaining positioning accuracy even when communications infrastructure was disrupted by using satellite augmentation signals (such as CLAS from the QZSS). RTK AR is effective for initial rapid surveys in emergencies and for remote technical support.

Challenges and Countermeasures for Implementation

Although RTK AR surveying is convenient, there are points to note when introducing and using it. Here are potential challenges and countermeasures.

• Matching the required accuracy: RTK AR positioning accuracy is generally on the order of a few centimeters (a few cm), but it is not suitable for millimeter-level precision or deformation measurements. For high-precision tasks such as control point surveys or deformation monitoring, optical surveying instruments or high-precision laser scanners remain necessary. It is important to select the appropriate method that meets the required accuracy according to the application.

• Dependence on GNSS environment: In downtown areas with tall buildings, wooded areas, or tunnels, GNSS signals may be blocked and accuracy may degrade. In such cases, switch to local surveying from known points (offset measurements), or perform positioning in an open area and then continue with relative measurement modes (indoor modes) using the IMU or AR. For critical locations, perform prior verification and, if necessary, combine with conventional methods or conduct redundant measurements to ensure reliability.

• Handling equipment and power management: The smartphone plus GNSS receiver combination is convenient, but on-site use requires attention to dust/water protection and battery management. For long surveys, use external power like mobile batteries and attach straps to prevent dropping the devices—these basic handling measures are essential. Although initial operation requires acclimation, many UIs are intuitive, so short-term on-site training can achieve proficiency.

• Compatibility with existing assets: When integrating survey results with existing drawings or GIS data, pay attention to coordinate system consistency. In Japan, public surveys require handling plane rectangular coordinate systems and geoid height references for elevation. Confirm in advance whether the AR surveying system supports these, and check data compatibility by cross-referencing output coordinates with existing coordinates. Take care to avoid misconfigurations that could cause discrepancies.

While there are such challenges, most can be overcome with appropriate countermeasures. By understanding the limits of the technology and using it wisely, you can fully enjoy the benefits of RTK AR surveying.

The Future of Surveying Opened by RTK AR

With the advent of RTK×AR technologies, the surveying field is beginning to change significantly. It is truly an innovation that “opens the future of surveying.” An era is approaching in which anyone can perform high-precision surveying with just a smartphone, and tasks that once depended on the craftsmanship of specialists are being digitized and automated. DX (digital transformation) is demanded in the construction industry—exemplified by initiatives such as the Ministry of Land, Infrastructure, Transport and Tourism’s i-Construction—and RTK AR could become one of the trump cards. AR-guided surveying can contribute to improving on-site productivity, alleviating labor shortages, ensuring quality, and enhancing safety, potentially becoming the new norm in construction management methods. In Japan, in particular, the style of a one-person-one-smartphone surveying terminal enabling single-person high-precision surveying and as-built management is gradually spreading. This is a breakthrough that was unthinkable in the past; enabling each engineer to measure, decide, and share on site in real time raises the overall efficiency and quality of construction work. Of course, RTK AR will not replace all scenes—total stations and conventional GNSS surveying will still be suitable in some situations. However, in day-to-day civil surveying and construction management, RTK AR is likely to permeate as an everyday tool. With the progress of 5G and next-generation satellite positioning promising further improvements in accuracy and reliability, AR-guided precision positioning is no longer a near-future concept but a current, emerging new standard.

Simplified Surveying with LRTK

Finally, as a solution that allows easy experience and introduction of RTK AR technology, we introduce LRTK. LRTK is a high-precision GNSS positioning platform developed by a startup originating from Tokyo Institute of Technology. With the concept of turning a smartphone into a surveying instrument with centimeter-level accuracy (cm level accuracy, half-inch accuracy), it provides a set of a dedicated small receiver, an app, and cloud services. For example, the palm-sized RTK receiver called the “LRTK Phone” is attached to a smartphone for use. Weighing only a few hundred grams and built with dust- and water-resistant specifications and an internal battery, it connects to the smartphone via Bluetooth or Lightning and supports RTK corrections over the network as well as Japan’s Quasi-Zenith Satellite System (QZSS: CLAS signal), enabling real-time positioning to within a few cm (a few in) anywhere in the country. Using the dedicated “LRTK app,” basic functions such as single-point measurement, continuous positioning, and averaging of measured points for improved accuracy are available, along with AR-specific features such as point visualization and navigation, and photo measurement (obtaining coordinates of objects captured by the camera). Measured points are plotted on a map on site, and photos are saved with high-precision position and orientation tags. In addition, cloud integration allows immediate sharing of survey data and photos with the office, and data management such as 3D display and downloading in a browser later can be done with a single tap. By utilizing LRTK, simple surveying with just a smartphone is possible without special expensive equipment. Covering everything from layout to recording and data sharing in an all-in-one solution, LRTK offers ease of introduction and cost advantages for small- to medium-scale construction sites and surveying projects. From the field, voices are heard such as “Thanks to LRTK, one-person-one-smartphone surveying has become a reality,” making it a driving force behind the normalization of RTK AR technology. If you are interested, please check LRTK’s official information.

FAQ

Q: What exactly is RTK AR? A: RTK AR is a new surveying method that combines high-precision GNSS positioning (RTK) with augmented reality (AR). RTK technology brings smartphone positions to centimeter-level accuracy, and those positions are used to overlay virtual markers and models onto real-world images. This enables surveying on site while visualizing design drawings and points.

Q: What equipment is required for AR surveying? A: Basically, you need a mobile device such as a smartphone or tablet, an RTK receiver that supports high-precision GNSS, and a surveying app that supports AR display. A small RTK receiver attachable to the smartphone is used to receive correction information from a base station over the network. An AR app that uses the device’s camera and sensors provides position guidance and data display. With these combined, one person can perform AR surveying.

Q: What level of positioning accuracy can be achieved? A: With RTK, under ideal conditions, horizontal accuracy of about 2–3 cm (0.8–1.2 in) can be expected. Actual field accuracy varies with satellite reception conditions, but it is a dramatic improvement over traditional standalone positioning (errors of several meters). Because AR surveying secures this centimeter-level accuracy, you can work at a level where you hardly feel any discrepancy between drawing points and the field. However, for millimeter-level precise measurements, other methods such as electronic distance measurement are required.

Q: What if GNSS is unavailable in a location? A: In places where satellite signals are hard to receive—such as in the shadow of buildings in urban areas, mountainous regions, or indoors—RTK positioning may be difficult. In such cases, switch to relative measurement methods from nearby known points, or fix RTK in an open area temporarily and then continue measurement using IMU and AR relative positioning. If augmentation signals from Japan’s quasi-zenith satellites (CLAS) can be used, accuracy can be maintained even outside communication zones. It is important to use the appropriate tools depending on the situation, sometimes combining with conventional surveying equipment.

Q: Can anyone handle AR surveying? Is specialized knowledge required? A: AR surveying systems provide intuitive user interfaces, and basic operations are not difficult. You can reach points by simply following on-screen instructions. However, knowledge of GNSS and coordinate systems makes it easier to use the system effectively, and proficiency in achieving accuracy and noting precautions comes with official training and on-site experience. Certification is not always mandatory, but for important surveying tasks, it is desirable to perform work under the supervision of licensed surveyors or other qualified personnel.

Q: Are introduction and running costs high? A: A setup of a smartphone, small RTK receiver, and app is often lower in cost than newly introducing total stations or conventional high-precision GNSS equipment. Especially if you already own tablets or smartphones, you may only need to bear the cost of the receiver and service fees. However, if you use satellite communication services or internet-based services (such as Ntrip) to obtain RTK corrections, usage fees may apply. There are solutions like LRTK that offer low-cost subscriptions or free augmentation signals, so consider your budget and frequency of use when deciding.

Thank you for reading to the end. RTK AR technology is transforming how surveying is done, and practical examples are expected to increase going forward. Take this opportunity to experience AR-guided precision positioning and explore the potential for improving your operations.