On-site Earthwork Quantity Management Is Changing! A Surveying Revolution with AR and 3D Technologies

Table of Contents

• Introduction

• Traditional on-site volume calculation methods and their challenges

• What are AR and 3D technologies? Applications to field surveying

• How AR and 3D technologies change on-site volume calculation

• Benefits of AR and 3D technologies for earthwork quantity management

• The future of on-site DX and the "surveying revolution"

• What is simple surveying with LRTK?

• FAQ

Introduction

Performing volume calculations for embankments and excavations at construction sites is an essential task for progress management and cost control. However, traditional on-site volume calculations have required significant time and effort and have typically depended on specialized surveying technicians. Imagine being able to measure the volume of soil instantly simply by pointing a smartphone at it—what once seemed like a dream is now becoming reality. Recent advances in AR (augmented reality) and 3D measurement technologies are poised to dramatically change how earthwork quantities are managed on-site.

Compared with conventional, manual surveying, the new methods that leverage AR and 3D technologies deliver dramatic efficiency gains and higher accuracy—what can rightly be called a “surveying revolution.” An era has arrived in which familiar devices such as smartphones and tablets can immediately perform 3D measurements on-site. Behind this are improvements in device performance (high-resolution cameras and LiDAR sensors), advances in positioning technologies (improved GPS accuracy thanks to Japan’s quasi-zenith satellite system Michibiki), and industry-wide digitalization initiatives such as the Ministry of Land, Infrastructure, Transport and Tourism’s *i-Construction*. In this article, we explain the challenges of traditional on-site volume calculations and how AR and 3D technologies address them. We also describe the benefits of adopting these new technologies and introduce a concrete, currently notable solution: simple surveying with LRTK, while envisioning the future of construction sites.

Traditional on-site volume calculation methods and their challenges

In civil engineering and construction, managing soil volumes—such as excavation and embankment volumes—is a routine task. Traditionally, these on-site volume calculations required considerable manpower and time. Common methods include the cross-section method and the grid method. For example, a surveyor sets up surveying equipment (a level or total station) and measures ground elevations at regular intervals to create many cross-sections or grid-based elevation data, then calculates volumes from those. On small sites, tape measures and leveling rods (staffs) may be used to measure a few points and estimate volumes roughly. These tasks require skilled surveyors, and because measurements and records must be made at each survey point, a single volume calculation could take anywhere from half a day to several days.

Manual methods have several drawbacks. First, accuracy is limited because it’s estimated from a limited number of points. Increasing measurement points improves accuracy but also increases labor. Second, there is the possibility of human error inherent in manual work; wrong measurement points or recording mistakes can introduce significant errors into volume calculations. Third, there are safety concerns. Surveying on high or steep slopes may require workers to enter dangerous areas, increasing the risk of accidents. Additionally, compiling survey results, drafting drawings, and performing quantity calculations require specialized knowledge, making it difficult for site personnel to grasp earthwork quantities in real time. Thus, traditional on-site volume calculation methods have suffered from being “time-consuming,” “labor-intensive,” and raising “concerns about accuracy and safety.”

What are AR and 3D technologies? Applications to field surveying

AR and 3D technologies can address these challenges. AR (Augmented Reality) overlays virtual objects and information onto the real-world view captured by a camera. For example, on a smartphone or tablet screen, you can display markers from design drawings or virtual stakes for on-site verification, or visualize measured data immediately. 3D measurement technologies acquire the shape of objects or terrain as three-dimensional digital data. Typical methods include laser scanning (LiDAR) and photogrammetry. The former obtains high-density point clouds by emitting infrared laser pulses, while the latter reconstructs three-dimensional shapes from multiple photographic images.

Recent smartphones have improved camera performance and, in some models, include LiDAR sensors, enabling 3D scanning with a single device. GNSS (satellite positioning) has also advanced—multi-GNSS and Japan’s quasi-zenith satellite system have dramatically improved standalone smartphone GPS accuracy. By attaching an external RTK-GNSS receiver to a smartphone, users can achieve positioning accuracy on the order of several centimeters (a few inches). Built on these technological foundations, AR apps and 3D scanning apps for field use have emerged, creating an environment in which anyone can easily perform 3D measurements on-site. So-called “mobile scanning” (field measurement using portable devices such as smartphones) is gaining attention because it has the potential to transform surveying and measurement tasks that previously relied on specialized equipment and skilled personnel.

Concrete applications to field surveying include: combining a smartphone with a small GNSS receiver to precisely position control points on-site, then using that smartphone to scan surrounding terrain and features to generate point cloud data and 3D models in real time. With AR, you can overlay acquired 3D data or pre-construction design models onto the real scene to check the expected finish or excavation extents on-site. Examples include using AR to display the positions of buried pipes before excavation as a safety warning, or projecting the designed finished shape onto the site to inspect as-built conditions. AR and 3D technologies thus bring significant innovation not only in “measuring” but also in “showing and communicating” on-site information.

How AR and 3D technologies change on-site volume calculation

So how exactly will on-site volume calculations change with AR and 3D technologies? The major difference from traditional methods is that the entire workflow—from measurement to volume computation—can be completed on-site. Previously, survey data were taken back to the office for calculations and drafting, but new technologies allow accurate on-site volume assessment in a short time. A simplified workflow for the new method is as follows:

• Reference setup: Attach an RTK-capable GNSS receiver to a smartphone and correct the device’s position to known site control points or reference elevations. This provides accurate geolocation (latitude, longitude, elevation) to the scanned data.

• 3D scanning: Launch a dedicated scanning app and walk around the soil or terrain to be measured while capturing images. On LiDAR-equipped phones, simply moving the device will capture point cloud data on the spot. On phones without LiDAR, photogrammetry can generate 3D models by photographing the target from various angles. In a short time you can collect hundreds of thousands to millions of measurement points, recording the shape of embankments or excavations in full detail.

• Volume calculation: After scanning, the device automatically generates a 3D model (point cloud data). Volume is then computed from this point cloud—for embankments, by calculating elevation differences from surrounding ground surfaces, and for excavations, by differencing the pre-excavation ground model. Dedicated apps or cloud services immediately display calculation results numerically and with color maps so you can instantly see where and how much soil is present.

• Data sharing and utilization: Calculated volume data and 3D models can be uploaded to the cloud and shared with stakeholders on the spot. Site supervisors and office engineers can share information in real time, facilitating additional checks and decision-making. Shared data can also be viewed as AR overlays on other devices to visually confirm on-site how much embankment is lacking compared with the plan.

Using AR and 3D technologies, a single operator can complete on-site volume measurement and calculation in a short time. For example, what used to require several people and a half day to measure cross-sections for an embankment can now be done by one person walking around with a smartphone in several tens of minutes. Since volumes are automatically computed from the acquired 3D data, manual calculations and drafting are eliminated. This enables non-specialist staff, such as site supervisors, to grasp earthwork quantities whenever needed, allowing rapid adjustment of earthwork plans and speedy procurement of materials and equipment—dramatically accelerating on-site decision-making.

Benefits of AR and 3D technologies for earthwork quantity management

The new surveying methods enabled by AR and 3D technologies offer a range of benefits beyond simply “faster measurement.” Major advantages include:

• Significant improvements in work efficiency and labor reduction: Large areas can be measured quickly, and a single scan can provide point cloud data that reveals the whole site. Information that was once fragmented when collected manually can now be obtained comprehensively, greatly reducing the time required for surveying. Since operation is generally possible by one person, multiple personnel need not be assigned. As a result, even limited staff can manage earthwork efficiently, helping address severe labor shortages.

• Improved measurement accuracy and data quality: Acquired point cloud data are far denser than conventional local survey points and capture subtle surface undulations of the ground and embankments in 3D. Height differences and irregularities that are easy to miss are visualized, improving volume calculation accuracy and ensuring reliable as-built verification against design. With RTK-enabled measurements, global coordinates such as public coordinate systems can be attached to each point, minimizing registration errors between multiple datasets and yielding highly reliable survey results.

• Enhanced safety (non-contact and remote measurement): Because measurements can be taken from a distance without entering hazardous areas, worker safety is improved. For example, soil volume measurements on steep or potentially unstable slopes can be recorded remotely simply by operating equipment from a safe location. Reducing the time spent near high places or heavy machinery lowers the risk of falls and contact accidents. Moreover, shortening measurement time itself reduces the duration spent in danger zones, providing immeasurable safety benefits.

• Low cost and low barrier to entry: While cutting-edge technologies often evoke images of expensive equipment, the smartphone-plus-small-sensor approach is relatively low cost. Previously, laser scanners required investments of several million yen, but many sites already have smartphones, and additional devices often cost less than a few hundred thousand yen, making adoption feasible for small and medium-sized enterprises and municipalities. No specialized operator is required, and app operation is generally intuitive, keeping training costs low. New or young staff accustomed to smartphones can handle the tools after short training. As a result, tasks that used to be outsourced can be brought in-house, leading to overall cost reductions in some cases.

• Data sharing and promotion of DX: Acquiring digital 3D data transforms the earthwork management process itself into DX (digital transformation). With cloud sharing, point clouds and measurement results obtained on-site can be immediately shared with the office and stakeholders, allowing remote monitoring of site conditions and issuing instructions. Everyone can discuss using the same 3D model, reducing misunderstandings and smoothing consensus building. The Ministry of Land, Infrastructure, Transport and Tourism has drafted the “Guidelines for as-built management using 3D measurement (draft),” formalizing as-built management using point cloud data, and 3D scanning and AR usage are becoming the industry’s new norm. Accumulating 3D data at each stage of construction also helps quantitatively track progress and serves as future maintenance documentation. Information that is hard to convey in text or 2D drawings becomes clear in visual 3D, deepening understanding among all stakeholders and improving transparency and reliability of site management.

The future of on-site DX and the "surveying revolution"

The surveying revolution driven by AR and 3D technologies is expected to accelerate further. Currently, smartphone- and tablet-based methods dominate, but these could evolve into AR glasses and greater automation in the future. For example, site supervisors wearing AR-capable smart glasses might simply look around and see necessary survey data and design information displayed in their field of view. That would enable hands-free, real-time earthwork quantity awareness and immediate adjustments to construction plans.

Integration with drones and robots is also conceivable. Aerial 3D surveying (UAV photogrammetry) is already used for large-scale earthworks; combining that with ground mobile scanning and AR would allow comprehensive data collection from both the air and ground. Advances in AI (artificial intelligence) are also noteworthy. AI could analyze massive point cloud datasets to automatically propose optimal earthwork plans or detect anomalies that warn of potential construction errors in advance.

Crucially, these technologies are being transformed from tools for specialists into tools that anyone on-site can use. The notion of “anyone can be a surveyor” is becoming realistic. As experienced technicians decline in number, intuitive digital tools will support sites so that the next generation can maintain high quality and safety. The surveying revolution is reshaping workflows across construction management, and its benefits will continue to expand. To avoid being left behind in on-site DX (digitalization), we must monitor trends in new technologies and adopt them proactively.

What is simple surveying with LRTK?

How can the AR and 3D technologies discussed above be actually used on-site? One answer is simple surveying with LRTK. LRTK (pronounced "el-arr-tee-kay") is a next-generation surveying solution that combines high-precision GNSS (RTK) and AR technologies using a smartphone. Specifically, by using a small RTK-GNSS receiver that can be attached to a smartphone and a dedicated app, the smartphone becomes a surveying instrument with centimeter-level accuracy (half-inch accuracy). On-site, simply carrying a smartphone + LRTK receiver set and walking around enables acquisition of high-precision 3D point clouds with positional information. Tasks that formerly required specialized equipment and experienced personnel can be performed intuitively by non-specialized site staff, enabling rapid surveying.

One feature of LRTK is the ability to display acquired point clouds and design data in AR on-site. For example, overlaying a point cloud model of a soil pile scanned with LRTK onto the real scene on a smartphone makes it easy to confirm differences between as-built and design shapes with a color-coded heat map. AR-guided virtual stake placement can guide marking accurate positions for control points. LRTK also integrates with cloud services, allowing on-site data to be uploaded instantly and shared with stakeholders. This enables remote verification of site 3D conditions and volume calculation results, dramatically accelerating information sharing.

In short, simple surveying with LRTK is a concrete solution that embodies the "surveying revolution through AR and 3D technologies" described in this article. Without purchasing special surveying instruments, you can enjoy state-of-the-art surveying simply by attaching a small receiver to your smartphone. For site personnel struggling with earthwork quantity management, LRTK is a powerful ally that delivers speed, safety, affordability, and simplicity. Experience this technological innovation that dramatically streamlines on-site volume calculations at many worksites.

FAQ

Q1. What can AR technology do? A. AR (augmented reality) overlays digital information onto the real-world view through a smartphone or tablet screen. On-site, you can overlay design shapes or survey data onto the actual scene for verification, or display virtual markings (stakes or lines) to guide work. In other words, AR enables you to intuitively grasp construction progress and as-built conditions on-site and to issue visually guided work instructions.

Q2. Can a smartphone really measure soil volume accurately? A. Even standalone smartphones with LiDAR or high-performance cameras can perform highly accurate 3D scans. Calculating volumes from point cloud data obtained by scanning embankments or excavations yields values far more accurate than manual estimates. However, for stricter accuracy requirements it is effective to perform position correction using RTK-GNSS and similar methods. For example, using an RTK-capable receiver such as with LRTK can reduce positioning errors to the order of a few centimeters (a few inches), greatly increasing the reliability of volume calculations.

Q3. Is the new AR/3D surveying usable by anyone? A. Yes—these systems are generally designed so that no special license is required. Dedicated apps have simple operations, and in many cases measurement is completed by following on-screen guidance while moving the smartphone. Compared with traditional surveying equipment, the user interfaces are more intuitive, allowing young site staff to learn quickly with short training. However, when preparing official as-built management documents, it is prudent to have a licensed surveyor review the final outputs as part of operational precautions.

Q4. How does this differ from drone surveying? A. Drone (UAV) photogrammetry can quickly acquire terrain data over wide areas, but aerial viewpoints may have blind spots and are not suitable for indoor or underground spaces where GPS is unavailable. Smartphone-based AR and 3D surveying (mobile scanning) measures details from ground level and performs well in confined sites or indoors. The two approaches complement each other: use drones for overall surveys of large sites and mobile scanning for detailed or indoor measurements.

Q5. What does LRTK stand for, and what are its benefits? A. LRTK is a product brand name derived from the company and its technical concept and is not an acronym for particular words (though it suggests a solution that utilizes Real-Time Kinematic (RTK) positioning). The main benefit of LRTK is that a smartphone becomes a high-precision surveying instrument. Without expensive dedicated equipment, you can achieve centimeter-level positioning and 3D scanning with simple devices, dramatically improving the efficiency of site surveying and volume calculations. Because positioning data, 3D data, and AR display functions are integrated, you can not only measure but also immediately verify and share results on-site. Ultimately, LRTK’s strength lies in simultaneously improving accuracy, saving time, and ensuring safety in earthwork quantity management.