Surveying × AR Civil Engineering: A New Era of On-Site Measurement with a Smartphone

Table of Contents

• Introduction

• Traditional Surveying Methods and Their Challenges

• What Is AR Technology?

• Advantages of Smartphone AR Surveying

• Examples of AR Use in Civil Engineering Sites

• Challenges to the Adoption of AR Surveying

• Promoting Simple Surveying with LRTK

• FAQ

Introduction

In recent years, leveraging smartphone AR (augmented reality) technology has made surveying work at civil engineering sites drastically easier. Surveying, which once required expensive and specialized equipment, has now entered an era where anyone can perform it easily with a single, familiar smartphone. This new technology is attracting attention for overturning the conventional wisdom that “surveying = difficult and arduous,” from veteran field engineers to beginners, and is expected to greatly reduce labor and improve efficiency. In this article, we explain the challenges of traditional surveying methods and how on-site measurement changes with the introduction of smartphone AR technology. We also present concrete examples of AR use in the civil engineering field, its benefits, and future challenges. Finally, we introduce LRTK, a high-precision simple surveying solution using smartphones, and propose a smooth pathway to adopting a new surveying style.

Traditional Surveying Methods and Their Challenges

First, let’s整理 how traditional civil surveying tasks were typically conducted, along with common procedures and issues. Conventional surveying generally used dedicated instruments such as total stations (TS), automatic levels, and tape measures, with multiple people measuring height and distance point by point. However, this analog-centric approach has been criticized for the following problems.

• Time and effort intensive: Because equipment must be set up and measurements taken painstakingly at each survey point, the larger the site the more time-consuming the process becomes. Including the time to record results and return to the office to reconcile drawings, it is not uncommon for as-built verification to take several days.

• Dependence on manpower and skilled technicians: Accurate surveying requires experienced surveyors and is usually performed by teams of two or more. The construction industry faces labor shortages and an aging technical workforce, making it difficult to secure adequate personnel at each site. As a result, reliance on the intuition and experience of a limited number of veterans becomes inevitable, increasing labor costs.

• Equipment cost burden: High-precision surveying requires expensive dedicated equipment such as TS or GPS surveying instruments (RTK-GNSS receivers), with initial investments running into the millions of yen. Small to mid-sized firms or sites often cannot afford to purchase equipment and thus outsource surveying. Equipment maintenance and theft prevention also impose costs and effort.

• Risk of human error: Manual surveying is prone to measurement errors and recording mistakes. Numbers can be transcribed incorrectly during on-site recording, or omissions can occur due to insufficient measurement points. If errors are discovered later, re-measurement becomes necessary, leading to additional rework.

• Difficulty working in hazardous areas: Surveying in hard-to-access places such as high slopes, the undersides of bridges, or narrow tunnels is challenging. Forcing access can endanger workers, so sometimes measurements are simply omitted; as-built verification for such locations remains a persistent problem.

• Data organization and reporting burden: After surveying, collected values must be compiled into drawings and reports, which demands substantial effort and time, burdening site supervisors. They often find themselves strapped with drawing creation and photo organization, working late into the night.

As described above, traditional surveying and as-built management require a lot of manpower and time while lacking real-time capability, and they heavily depend on specialized technicians. Ensuring safety while maintaining accuracy is not easy, and even well-measured data can be underutilized due to the time needed for organization and reporting. To address these issues, digital transformation (DX) in the construction industry is being vigorously promoted under keywords such as ICT construction and i-Construction. Among these, the application of AR technology is receiving particular attention.

What Is AR Technology?

AR (Augmented Reality) overlays digital information onto real-world images captured by a camera. Through a smartphone or tablet, you can composite and display 3D models, text, and other digital content onto the actual site view. Once an advanced research-stage technology, AR has evolved—thanks to improvements in mobile device performance—into a level usable in everyday field operations. For example, many modern smartphones are equipped with high-performance cameras and LiDAR sensors (laser-based distance measurement sensors), enabling intuitive on-site “visualization.”

Adoption of AR technology is progressing in construction and civil engineering as well. AR’s major advantage is its ability to visualize information that is hard to convey with drawings and numbers alone directly in the field. For instance, displaying a full-scale model of a planned structure over the actual site lets the client and all site staff share the same completion image visually. This reduces misalignment in understanding and dramatically speeds up consensus building and instruction. Since you can directly indicate locations from the drawing onto the site via the smartphone screen, AR greatly reduces communication loss with the adage “seeing is believing.”

Advantages of Smartphone AR Surveying

So how does combining smartphones and AR change on-site surveying? Considering the conventional challenges, smartphone AR surveying offers the following advantages.

• Labor savings and speed improvements: Measurements can be taken simply by walking around the site with a single smartphone, eliminating complex equipment setup and the need for multiple personnel. One person can measure wide areas quickly, dramatically shortening surveying time. In practice, tasks that used to take two days have in some cases been completed in half a day, contributing to significant reductions in work time.

• Real-time verification: Data obtained by AR measurement is recorded digitally on the spot and immediately visualized. Measured points appear instantly on the smartphone screen and can be shared with the office via the cloud, enabling on-the-spot validation and decision-making. Being able to check as-built accuracy immediately after construction reduces the risk of later-discovered problems and prevents rework.

• High intuitiveness and information density: Because measurement results and design models can be overlaid on the camera view, situations are easy to understand intuitively. For example, displaying the measured point’s height and position in AR lets you instantly see what was measured. Measuring the terrain comprehensively as point cloud data (a collection of many measurement points) reveals fine irregularities and overall form that single-point measurements cannot show. The result is high-information-density measurement that is easy to achieve.

• Cost reduction: In many cases, measurements can be performed with existing smartphones and an app without special surveying equipment, reducing the need for new equipment investment. This reduces the frequency of renting equipment or outsourcing surveying, lowering total costs. Additionally, devices are typically compact, lightweight, and powered by internal batteries, reducing carrying and management burdens.

By introducing smartphone AR surveying, “fast, simple, and easy-to-understand” surveying becomes possible, significantly enhancing on-site productivity and decision-making speed. The next section looks at specific scenarios in civil engineering where these advantages can be realized.

Examples of AR Use in Civil Engineering Sites

By using AR technology on smartphones or tablets, various new measurement and construction methods become possible on civil engineering sites. Below are representative application examples.

• 3D scanning and earthwork volume measurement: Using smartphone LiDAR and similar sensors, you can obtain point cloud data of surrounding terrain and structures simply by walking around the site. A single scan can record millions of measurement points, allowing complex slope shapes and expansive development sites—previously only partially measurable—to be visualized in full 3D. Distances, areas, and volumes can be calculated immediately from the acquired point cloud, enabling rapid on-site earthwork volume calculations and as-built quantity estimation.

• Immediate as-built verification and quality control: One strength of AR is the ability to verify whether the constructed shape matches the design on the spot. By comparing as-built data captured on a smartphone with a 3D design model in the cloud, a color-coded heat map of differences can be generated instantly. Displaying that heat map in AR on the smartphone makes it immediately clear which parts are higher or lower than the design. For example, if pavement thickness is insufficient, it can be identified immediately after construction and repaired right away. Such real-time inspection greatly contributes to preventing overlooked quality issues and reducing rework.

• AR-guided piling and layout marking: Traditionally, positions for structures were set out using batter boards and layout marking, but AR can display design positions directly on the screen, enabling installation guided visually. For example, if piling coordinates are pre-registered, the smartphone screen can show arrows or markers indicating “drive the pile here.” Less-experienced workers can pinpoint accurate positions without hesitation, and AR guidance helps locate points even when vegetation or snow obscures physical markers. This improves efficiency and reduces errors in layout and surveying tasks.

• Sharing completion images and building consensus: Displaying the completed form at full scale in AR allows all stakeholders to share the finished-image on-site. For instance, showing how a new bridge or road will look within the surrounding landscape makes it easy for non-experts to understand. Using this during explanations to clients or nearby residents addresses the difficulty of imagining the finished result and smooths consensus building. Overlaying the model on the actual scenery increases persuasiveness and shortens the time needed for discussions and approvals.

As these examples show, the AR approach in civil engineering not only enhances surveying but also delivers major benefits in construction management and communication. Smartphone AR technology is becoming a new tool that simultaneously improves accuracy, reduces labor, and enhances safety across tasks such as earthwork management, as-built inspection, layout marking, and design explanation.

Challenges to the Adoption of AR Surveying

On the other hand, there are challenges to address when popularizing smartphone AR surveying at sites. The main points are listed below.

• Improving positioning accuracy: Standalone smartphone GPS accuracy can have errors on the order of several meters (several ft), which is insufficient for conventional surveying accuracy. Camera-based AR distance measurements can also have errors on the order of a few percent. High-precision positioning technologies such as RTK (Real Time Kinematic), which use correction information from base stations, are key to achieving high-accuracy positioning. Combining a small RTK-capable GNSS receiver with a smartphone can reduce positioning errors dramatically to below a few centimeters (a few in), bringing accuracy closer to surveying-grade.

• Familiarization and acceptance of the technology: AR surveying, as a new digital technology, may initially seem challenging, especially to workers accustomed to traditional surveying methods. Some may be unfamiliar with smartphone operation or app usage. However, current AR surveying apps are designed with intuitive interfaces, and basic operations are not difficult. They are structured so that anyone can master them with short training or trial use. For adoption at sites, it is important to provide in-house training and pilot implementations on small projects so users can gradually become accustomed.

• Operational environment constraints: When using smartphone AR on outdoor civil sites, you must consider weather and environmental impacts. Direct sunlight can make screens hard to see, rain requires waterproofing, and batteries drain faster in cold regions. In addition, because AR relies on the smartphone camera for position detection, alignment can be unstable in locations with few distinctive features. These issues can be mitigated by using sunshades, protective cases, spare batteries, and target markers.

• Regulatory and operational framework development: Introducing new technology requires standards and operational rules for treating the data officially. For example, accuracy management methods when conducting as-built management with smartphone point clouds, or standardizing data formats for electronic delivery, need industry-wide standardization. However, under the Ministry of Land, Infrastructure, Transport and Tourism’s i-Construction initiative, standards for the use of digital measurement are being developed, and it is expected that AR surveying data will increasingly be used formally for inspection and delivery.

Although these challenges exist, they are being addressed as technology advances. The miniaturization and cost reduction of RTK technology and improvements to apps are steadily resolving concerns about accuracy and usability. The LRTK introduced next is one smartphone surveying solution designed to overcome these challenges and enable easy adoption by anyone.

Promoting Simple Surveying with LRTK

Smartphone surveying is overwhelmingly more convenient than traditional surveying equipment, but as noted, achieving high accuracy requires RTK-capable GNSS receivers and dedicated apps. Enter LRTK, a solution that turns a smartphone into a centimeter-class surveying instrument (centimeter-level accuracy (half-inch accuracy)). LRTK is a system that equips a smartphone or tablet with a small, high-precision GNSS module and combines it with a dedicated app so anyone can easily perform high-precision positioning and measurement alone.

Features of LRTK:

• Achieves RTK positioning with a small GNSS receiver attachable to a smartphone, reducing outdoor position errors to about 1 cm (0.4 in). Connection via the smartphone’s Bluetooth, etc., requires no special settings or complicated operations.

• The dedicated surveying app provides an all-in-one workflow from point positioning to 3D scanning, piling position navigation, and AR-based as-built checks. Tap a point to record coordinates instantly, and walk around to perform area-based 3D measurements.

• Measurement data can be synchronized and stored to the cloud on-site, minimizing the need for post-site data processing in the office. Point cloud models and heat maps automatically calculated in the cloud can be checked while still at the site.

• Easy to introduce and operate, even beginners without specialized knowledge can use it intuitively. It eliminates cumbersome calibration tasks typical of traditional surveying equipment; following the guided steps gets you measuring quickly. It is durable for on-site use, lightweight, and convenient to carry.

With LRTK, a single smartphone plus a small device can provide accuracy and functionality comparable to large surveying instruments. LRTK series products are already being introduced in the construction and civil engineering industries and are attracting attention as next-generation surveying solutions compatible with the Ministry of Land, Infrastructure, Transport and Tourism’s i-Construction. If you feel burdened by on-site surveying effort or accuracy issues, consider LRTK as a simple smartphone-based surveying option. It is likely to overturn the long-held image that “surveying is difficult” and must be left to specialists.

FAQ

Q1. How accurate can smartphone AR surveying be? A1. Standalone smartphone AR measurements can have errors on the order of a few percent and are not suited to millimeter-level precision. However, recent LiDAR-equipped devices have improved distance measurement errors to the order of several centimeters (several in) to several millimeters (several in). Combining high-precision GNSS (RTK) can yield planimetric positioning accuracy of about 1 cm (0.4 in) and vertical accuracy on the order of several centimeters (several in). In other words, with appropriate correction technologies, smartphone AR can achieve accuracy close to that of conventional surveying instruments. Because accuracy varies with environmental conditions and measurement methods, it is prudent to operate with safety margins for critical measurements or to verify with conventional instruments when necessary.

Q2. Can AR surveying be used without specialized knowledge? A2. Yes—basic operations can be learned by anyone. Many AR surveying apps have intuitive UIs designed for non-specialists, allowing measurements simply by aiming the smartphone camera and tapping. While understanding surveying principles and data interpretation enhances utilization, advanced expertise and manual calculations like those required for total stations are not necessary. With short training or by following manuals, site personnel can perform surveying tasks themselves. Solutions such as LRTK also offer robust support systems, making first-time adoption reassuring.

Q3. What kinds of sites and applications suit smartphone AR surveying? A3. Smartphone AR surveying is powerful for general on-site measurements in civil and construction works. Examples include topographic surveys and earthwork volume calculations at development sites, as-built inspections for roads and bridges, recording locations of buried objects, pavement thickness checks, and lot checks in land development. It is also useful for pre-construction condition surveys, interim inspections, and data collection for post-construction deliverables. However, millimeter-level precision tasks (such as precise control point measurements or displacement monitoring) and legally defined boundary surveys may still require traditional equipment and professional surveyors. By selecting the appropriate method for each use, most routine on-site surveying can be streamlined with smartphones while reserving conventional methods for specialized tasks.

Q4. What is needed to introduce AR surveying? A4. At minimum, an AR-capable smartphone or tablet and a surveying application are required. For higher accuracy, attaching a small RTK-GNSS receiver to the smartphone enables centimeter-level surveying. Products like LRTK supply a smartphone-mountable GNSS device and a dedicated app, allowing fast implementation of high-precision AR surveying on-site. Initial setup is not difficult—connect the device and app, and receive satellite correction information to stabilize positioning in a short time. Because existing smartphones can be utilized, adoption is easier than purchasing large new instruments.

Q5. How will AR technology develop in the civil engineering field in the future? A5. AR technology is expected to become indispensable as accuracy and convenience continue to improve. On the hardware side, smartphone camera and sensor performance will keep advancing, and AR glasses (wearable displays) are likely to become more common. This could enable workers to use headsets hands-free while checking AR information. On the software side, integration with AI and cloud services may allow automatic extraction of required dimensions from captured footage and real-time feedback for completion inspections. Government and industry initiatives promoting digital construction are ongoing, and an era where “digital measurement is commonplace for everyone” is drawing near. Familiarizing yourself with AR surveying now will undoubtedly help improve on-site capabilities in the future.