i-Construction-era Surveying Innovation: Boosting Productivity with Drones & Smartphones

The construction industry is currently undergoing unprecedented innovation in the field of surveying. Under the momentum of i-Construction, promoted by the Ministry of Land, Infrastructure, Transport and Tourism, advanced surveying technologies that leverage familiar tools such as drones (unmanned aerial vehicles) and smartphones are increasingly being adopted on sites. These technologies have the potential to solve problems like labor shortages and heavy workloads, dramatically improving productivity. This article focuses on surveying: it explains the overview and background of i-Construction, the emergence of drone surveying and smartphone surveying (RTK technology), and how point cloud data processing, AR, and cloud usage are changing on-site practice. It also presents recent field cases demonstrating labor savings and shortened schedules, and concludes by touching on the advantages of the easy-to-adopt smartphone surveying solution LRTK.

What is i-Construction: Background and Objectives in the Surveying Field

i-Construction is an initiative proposed by the Ministry of Land, Infrastructure, Transport and Tourism since fiscal 2016 to revolutionize productivity at construction sites【[Ministry of Land, Infrastructure, Transport and Tourism i-Construction](https://www.mlit.go.jp/tec/i-construction/index.html)】. It aims to fully utilize ICT (information and communication technology) across the entire construction production process—from investigation and surveying to design, construction, inspection, maintenance, and renewal—to raise individual worker productivity and thereby achieve both operational efficiency and workstyle reform. Specifically, it seeks to advance safe and rapid construction through use of 3D data, introduction of new surveying methods such as drones and laser scanners, and deployment of ICT-equipped machines (machine guidance and machine control).

The background includes a decline in construction engineers due to an aging and shrinking population, issues with skills transfer, and a desire to transform the construction site image—traditionally associated with the three Cs ("tough, dangerous, dirty"), known in Japan as the 3K—into workplaces that appeal to younger generations. The government has set a goal of improving construction site productivity by 20% by fiscal 2025 and has also drawn up a roadmap aiming for 1.5× productivity (a 30% reduction in required manpower) by fiscal 2040 as "i-Construction 2.0." Surveying is particularly highlighted as a first step: digitizing and automating previously manpower-centered surveying work is expected to greatly reduce workload while maintaining both accuracy and speed.

Traditionally, on-site surveying has been dominated by skilled surveyors setting up transits or total stations (electronic distance meters) while staff hold rods to measure numerous points. Surveying large areas or complex terrain took days and many workers, and carried risks in hazardous locations. In the i-Construction era, this is changing dramatically. Innovative methods such as aerial photogrammetry using drones and smartphone surveying using RTK-GNSS now enable anyone to acquire accurate 3D site data quickly and safely. The next sections examine the basics and impacts of these new technologies in detail.

What is Drone Surveying? Basics and Benefits of Aerial Photogrammetry

An indispensable element when discussing i-Construction is drone (UAV) surveying. The core of drone surveying is mounting a high-resolution camera on a drone to take numerous aerial photos of a site, then using photogrammetry to process those photos into accurate terrain models and orthophotos. Captured images are tagged with GPS and RTK positional data, and specialized software or cloud services compute 3D coordinates from overlapping photos to generate high-density point clouds and detailed terrain maps. In some cases, drones are equipped with laser scanners (LiDAR) to directly capture 3D point clouds, but camera-based aerial photogrammetry is widely adopted in many sites because it is more cost-effective.

Advantages of drone surveying: Drone surveying can acquire terrain data for large sites—data that previously took people days to measure—in a short time (a few hours to a single day). For example, a site that required several days of ground-based point collection can yield tens of millions of points from the air, enabling construction of a detailed 3D terrain model in as little as half a day. This not only significantly shortens project schedules but also provides far higher point density than manual measurements, allowing accurate capture of subtle undulations and earthwork volumes.

Safety improvements are another major benefit. Drones can remotely record conditions in steep slopes, cliffs, or areas where heavy machinery operates—places hazardous for personnel. Because surveyors no longer need to enter dangerous locations or perform layout tasks next to operating heavy equipment, the risk of workplace accidents is reduced. In practice, adoption of drone surveying in sites with mountainous steep slopes has almost eliminated the need for workers to go onto high-angle terrain, markedly improving safety.

Moreover, precise 3D data obtained by drones supports subsequent design and construction management. Orthophotos (top-down photographic maps) can serve as current plan views, while point clouds allow extraction of arbitrary cross-sections and can be used for buried cultural property surveys or inspection of as-built shapes. The Ministry of Land, Infrastructure, Transport and Tourism has long prepared draft guidelines for as-built management using drone photogrammetry and has promoted drone use for earthwork measurement. As a result, volumes for fills and excavations can be computed from aerial data, streamlining earthwork quantity management that was previously performed manually.

The Rise of Smartphone Surveying and the RTK Positioning Revolution

Alongside drones, the emergence of smartphone-based surveying deserves attention. Recent smartphones have improved not only camera and sensor performance but also GNSS (global navigation satellite system) reception capabilities. Especially with the spread of RTK (Real Time Kinematic) high-precision positioning technology, smartphones are undergoing a revolution as surveying instruments.

What is RTK positioning: Conventional GNSS positioning has meter-level errors, but RTK achieves centimeter-level accuracy by computing in real time the differences between satellite signals received simultaneously by a base station (reference) and a rover (receiver) to cancel out errors. Historically, RTK surveying required dedicated high-precision GNSS receivers costing hundreds of thousands of yen and radio equipment, and operation demanded specialized knowledge. Today, however, by attaching a compact RTK receiver to a smartphone or leveraging dual-frequency GNSS chips built into modern phones, a smartphone can effectively function as a high-precision GNSS survey instrument.

This smartphone surveying revolution is underpinned by a nationwide GNSS reference station network and services that deliver real-time correction data. If a smartphone receives networked RTK (VRS) correction information via mobile communication, centimeter-level positioning is possible without provisioning a dedicated base station. Japan’s quasi-zenith satellite system "Michibiki" also provides CLAS (Centimeter Level Augmentation Service), enabling reception of correction data from satellites even when outside terrestrial communication coverage, making smartphone RTK surveying feasible in mountainous areas. With this technological infrastructure, the environment in which "a smartphone alone can perform precise surveying" is becoming a reality.

Benefits of smartphone surveying: Its greatest advantages are ease of use and portability. Using a smartphone that fits in a pocket, surveying can be completed even by a single person. For example, GNSS surveys that formerly required two-person teams can now be performed by one person equipped with a smartphone and a small receiver. Heavy tripods and mounting rigs are unnecessary. Intuitive smartphone app interfaces make the workflow accessible to site staff who are not specialized surveyors. Because high-precision coordinates are available in real time, you can verify positions on the spot and proceed to the next task immediately, greatly speeding up the workflow.

Smartphones also integrate cameras, accelerometers, and electronic compasses, enabling combined data acquisition such as taking geotagged photos during positioning or overlaying virtual models onto measured locations with AR. Previously, field surveying required separate tools—survey instruments for measurements, cameras for photos, and notebooks for notes—but smartphone surveying can handle all of these in a single device, representing a wholesale transformation of surveying workflows.

Practical Changes from Point Cloud Processing, AR, and Cloud Utilization

With these new technologies, how surveying data is used and site management methods are changing considerably. In particular, the use of 3D point cloud data, AR (augmented reality), and cloud services are key to streamlining and enhancing surveying operations and subsequent processes. Below are the changes these component technologies bring to the field.

• Utilization of 3D point cloud data: Point clouds obtained from drones, terrestrial laser scanners, or smartphone photogrammetry are digital replicas of site terrain and structures represented by countless measured points. They contain vast detail beyond what plan or cross-sectional drawings can capture and are powerful for comparison with design drawings and as-built/finish management. For example, checking whether a completed embankment matches the designed slope can be done with point cloud data to instantly identify areas requiring correction. Point cloud processing software or cloud tools can display color-coded heat maps that visually indicate deviations from design data, improving quality control precision and simplifying as-built inspections.

• On-site use of AR technology: AR overlays 3D data onto live camera views on tablets or smartphones, enabling a real-world/digital fusion on site. By AR-displaying point cloud models of current conditions or 3D design models, teams can, for example, project buried utilities on the ground before excavation so operators can easily avoid digging at forbidden locations. AR can also superimpose planned structures onto the current site to share visualizations of the finished appearance with clients or neighboring residents. AR thus enables information that is hard to convey with drawings or numbers to be shared visually, reducing communication loss and accelerating decision-making.

• Integration with cloud services: Cloud utilization for surveying data is becoming commonplace. Previously, field-collected data had to be transported on USB drives and manually processed in the office. Today, smartphones and tablets can upload point clouds and survey data directly to the cloud for immediate sharing both inside and outside the organization. Remote office engineers can review the day’s data and make design adjustments the same day, and the site can download and apply updated data the next day—enabling real-time collaboration. Heavy processing tasks (e.g., converting photos to 3D or analyzing large datasets) can be run in the cloud, reducing dependence on on-site PC capabilities and allowing rapid deliverable creation. Accumulated cloud data can also be used in future maintenance, enabling temporal change comparisons and cross-site knowledge sharing. Cloud integration is transforming surveying into a seamless process that spans site and office.

Examples of Labor Savings and Schedule Reduction on Surveying Sites

What concrete effects have the innovations described produced on actual surveying sites? Here are some results from projects that adopted i-Construction early, showing how they achieved labor savings and shortened schedules.

• Significant reductions in working hours: In civil works utilizing ICT, the Ministry of Land, Infrastructure, Transport and Tourism reported an average reduction of about 30% in total man-hours from initial surveying to construction completion. Even considering only surveying, some cases achieved reductions to a fraction of previous durations. For example, an initial topographic survey that normally took around four days was completed in just half a day after introducing drone aerial photogrammetry. In another case, UAV use shortened the initial survey from one week to two days. Shorter surveying periods let construction start earlier, reducing overall project timelines.

• Labor savings and more effective personnel deployment: New technologies also reduce required personnel and allow better allocation of labor. In the aforementioned road project, two workers had previously been tied up for 1.5 days each week for surveying and layout, but ICT adoption made such manual tasks nearly unnecessary. The freed personnel could be reassigned to other tasks, improving the general contractor’s operational efficiency and work environment. Survey automation and labor reduction make it possible for sites with labor shortages to operate with fewer people, helping alleviate workforce constraints and reduce overtime.

• Improved safety: Drones and remote surveying equipment have dramatically raised on-site safety. On a site that included a steep slope, using a terrestrial laser scanner (TLS) allowed completion of surveying without sending people into hazardous high areas. Consequently, the risk of worker falls approached zero, and the surveying period was reduced from 17 days to 9 days (about a 50% reduction), achieving both safety and efficiency. During construction, ICT-equipped machines and 3D design data have eliminated the need for layout work around heavy machinery, allowing operators to work with confidence that no personnel are nearby—improving on-site safety awareness and productivity simultaneously.

• Ensured quality and accuracy: Immediate use of digital surveying data also directly improves construction quality. For example, real-time monitoring of fill and cut volumes using detailed as-built point clouds from drones or smartphones enables quick corrections so work conforms to design. Instead of conducting post-construction cross-section surveys for quantity settlements, measuring during construction reduces rework and material waste. Reports also indicate that younger engineers can achieve accuracy comparable to veteran staff by using 3D design and surveying guidance functions, suggesting digital technology supports skills transfer.

Examples of Advanced Initiatives by Local Governments and Companies

As the benefits described have been demonstrated across many sites, municipalities and construction firms nationwide are increasingly adopting advanced measures. The Ministry of Land, Infrastructure, Transport and Tourism annually recognizes outstanding i-Construction case studies with awards like the "i-Construction Awards," and momentum for ICT adoption is rising among local governments and small-to-medium construction companies.

Municipal initiatives: One local government encouraged and supported contractors to use drone surveying and ICT-equipped machines for road maintenance projects, achieving shorter schedules and cost reductions. In disaster response, municipalities are increasingly using drones and 3D surveying to assess affected areas. For instance, following a major landslide, a site that previously took days to survey manually was surveyed by drone in a single day, enabling rapid restoration planning. Such government-led ICT adoption has spillover effects on local construction firms, spreading the concept of "digital-capable sites" nationwide.

Corporate initiatives: Beyond large construction firms, small and medium companies are actively adopting advanced technologies. Some forward-looking contractors have established in-house ICT teams to train employees in drone operation and point cloud processing. They have distributed tablets to sites and standardized 3D design data, promoting company-wide digital talent development and on-site support. This has created a virtuous cycle: firms that excel in ICT-enabled projects gain competitive advantages in bidding. Another contractor reported that young staff using smartphone surveying and AR could manage sites and ensure quality and safety without relying on veteran experience, contributing to a workstyle change that overturns traditional norms.

A common factor in successful examples is a "willingness to start early and share know-how across the entire organization." Organizations that do not spare investment and education in digitalization achieve both productivity improvements and better working conditions. In the i-Construction era, technology won’t be adopted by waiting; real transformation happens when each site member experiences and recognizes the benefits of new tools.

Conclusion: Easy Surveying DX with Smartphones × RTK

The future envisioned by i-Construction is no longer limited to a few large-scale projects. Surveying solutions using drones and smartphones are evolving daily and have reached a stage where they are accessible to everyone in terms of cost and technology. The important thing is to "try it on-site, even small-scale, first." A perfect first step is adopting smartphone surveying tools that enable high-precision measurement easily.

For example, LRTK is a groundbreaking solution that allows anyone to achieve centimeter-level positioning simply by attaching a compact RTK-GNSS receiver to a smartphone. With a pocket-sized device, users can perform coordinate measurement, 3D point cloud scanning, stakeout tasks, and even AR overlay of the finished image—making it an all-in-one surveying tool. Captured data can be shared in real time via the cloud, allowing immediate sharing of site-measured information with the office or subcontractors and on-the-spot calculations of distances, areas, and volumes. The app is designed for intuitive use by staff without specialized training, and by equipping each worker with a personal surveying device—"one survey instrument per person"—teams can lift overall productivity. Because the introduction cost is lower than for traditional surveying equipment, small sites and budget-limited projects can also adopt it easily.

Surveying is undeniably changing now. By leveraging familiar technologies such as drones and smartphones, objectives like reduced working hours and labor savings—once considered out of reach—are attainable. In the i-Construction era, competitive advantage depends on how quickly new technologies are adopted and used on site. Take this opportunity to experience the benefits of simple surveying with smartphones × RTK. Adopting easy-to-use tools like LRTK can let your site take the first step toward productivity improvement as soon as tomorrow. Embrace cutting-edge surveying technology and help shape the future of construction sites together.