• Challenges and limits of conventional point cloud surveying

• Advantages of smartphone point cloud surveying

• Benefits of sharing point cloud data in the cloud

• Improved work efficiency through real-time collaboration between site and office

• Simple smartphone surveying enabled by LRTK

• FAQ

Manage site point cloud data with your smartphone! Improve work efficiency through cloud integration

In recent years, measurement and construction management using point cloud data has attracted significant attention in construction and civil engineering sites. Point cloud data are three-dimensional data that digitally record objects such as buildings and terrain as innumerable points, and once acquired you can freely measure dimensions or check cross-sections on the point cloud. However, traditionally obtaining high-precision point cloud data on-site required specialized equipment and advanced techniques such as expensive 3D laser scanners or drone photogrammetry. As a result, the initial costs were extremely high, and adoption progressed mainly at large-scale sites.

Thanks to technological advances, we have now entered an era where anyone can easily perform 3D scanning with only a smartphone and acquire high-precision point cloud data. Because the initial cost is dramatically lower than that of dedicated equipment, using 3D measurement has become realistic even for small sites. The attention on this “point cloud surveying with smartphones” is driven by the need to improve on-site productivity and ensure quality, as well as the construction industry’s broader push for DX (digital transformation). By utilizing 3D point cloud data, construction status can be recorded and understood in detail and with accuracy, dramatically improving as-built control and quantity calculation efficiency. In fact, some sites that adopted smartphone point cloud systems reported that surveying work time was reduced by as much as 90%, and point cloud technology is becoming a trump card for productivity revolutions on site. In addition, with the Ministry of Land, Infrastructure, Transport and Tourism promoting *i-Construction*, the use of 3D models (BIM/CIM) in public works has been made essentially mandatory from fiscal year 2023. As the industry-wide shift from 2D drawings to 3D data advances, workflows for smartphone-based point clouds—affordable and easy to use—are increasingly expected to become essential solutions for both field operations and management departments.

Another advantage of smartphone-based point cloud processing is that processing can be completed on-site without using a PC. Traditionally, processing and analyzing point cloud data required high-performance PCs and specialized software, meaning data captured on-site had to be taken back to the office for PC-based analysis. If smartphone and cloud integration allows processing to finish on the spot, the need to return to the office for processing is eliminated, and results can be immediately checked and shared. For these reasons, workflows that handle point clouds on-site with “PC-less, smartphone-only” setups are now drawing considerable attention. This article reviews the challenges and limits faced in conventional point cloud surveying and explains in detail the benefits of a new point cloud data management method using smartphones and the cloud. We will cover concrete points that dramatically improve on-site work efficiency and, at the end, introduce a solution called LRTK that enables simple smartphone surveying.

Challenges and limits of conventional point cloud surveying

First, let’s organize the challenges encountered when acquiring and utilizing point cloud data using conventional methods. Historically, 3D site measurement has been dominated by specialized equipment such as optical surveying instruments like total stations and large 3D laser scanners. These devices are very expensive and heavy, making them difficult to bring to the site. For example, total stations require tripod setup and typically two-person teams, and they require periodic calibration and maintenance, which involves sending them back to the manufacturer. Also, typical GNSS positioning (GPS) has errors of about 5-10 m (16.4-32.8 ft) without correction, making it difficult to use for high-precision surveying. On the other hand, ground-based laser scanners and UAV (drone) photogrammetry for point cloud surveying require specialized operators and high-performance PCs, and data processing takes time. Acquired point cloud data may include hundreds of thousands to hundreds of millions of points, resulting in very large file sizes that are difficult to display or edit without dedicated software and workstation-class PCs.

For these reasons, even if detailed 3D data were obtained, it was difficult to utilize or share immediately on-site, and staff had to return to the office to process and analyze the data and recompile it into 2D drawings or reports as needed. Naturally this introduced time lags, delaying detection of on-site problems, and often resulting in inefficient re-visits when additional measurements were found necessary. Due to cost and effort, many small sites gave up on 3D point cloud surveying altogether and continued managing with traditional tape measures and levels and 2D drawings. In short, conventional point cloud surveying and utilization had limits such as “equipment is expensive and heavy,” “specialized knowledge is required,” “data processing requires time and high-performance PCs,” and “data sharing is not smooth.”

Advantages of smartphone point cloud surveying

So, what are the advantages of point cloud surveying using smartphones? With smartphone performance advances, site staff can now simply take a smartphone from their pocket and scan the surroundings to perform easy 3D surveying. Specific benefits include:

• Ease and labor saving: Point clouds can be acquired using a smartphone and common apps, so there is no need to transport or set up heavy equipment. Surveying can be completed quickly by one person, greatly improving tasks that previously required two or more people and half a day. The convenience of being able to measure whenever needed is ideal for routine recording and progress management.

• Low cost: By utilizing existing smartphone hardware (built-in LiDAR sensors or cameras), the initial cost is significantly lower than purchasing a dedicated 3D scanner. Even when using external devices, inexpensive, compact GNSS receivers and poles as minimum necessities can produce results comparable to costly conventional equipment.

• High-precision positioning: While standalone smartphone GPS accuracy is on the order of several meters, linking the smartphone to a small GNSS device that supports RTK (real-time kinematic) enables positioning accuracy of several centimeters (a few inches). This allows the acquired point cloud to be precisely overlaid with plans and design data. Achieving surveying precision comparable to conventional equipment with just a smartphone plus a small receiver is a major advantage.

• Real-time processing: Scanned data are generated and displayed as 3D point cloud models within the smartphone app on-site. Thanks to improved smartphone CPU/GPU performance and cloud services, point cloud processing that used to take hours on a PC can now be completed in a short time. Being able to check the point cloud on the smartphone screen immediately after scanning lets you notice missed areas and perform additional measurements on the spot, preventing return visits for re-measurement.

• Simplicity anyone can use: Even without operating specialized equipment or expert knowledge, point cloud surveying is possible by following intuitive smartphone app UIs. Because 3D surveying can be done as easily as taking photos or videos, less experienced workers can handle it, reducing training costs. With site staff themselves able to acquire data, communication losses are reduced and responses become faster.

As described above, smartphone point cloud surveying combines “speed and ease,” “low cost,” “sufficient accuracy,” “immediate feedback,” and “simple operation,” and has the potential to significantly overhaul conventional methods. Even smartphones without LiDAR can generate point clouds using photogrammetry by taking multiple photos with the camera. In other words, not only the latest high-end devices but also smartphones that many site staff already own can be utilized.

Benefits of sharing point cloud data in the cloud

Point cloud data acquired with a smartphone truly shine when integrated with cloud services. Uploading and sharing data in the cloud offers the following advantages:

• Immediate on-site sharing: If on-site point cloud data, photos, and measurement point information are uploaded to the cloud via mobile networks, distant office PCs and stakeholders can check the site status in real time. Managers who previously had to wait for reports or later drawings from the site can immediately view the latest 3D data in the cloud.

• Viewing large-volume data: Cloud viewers can display large point cloud datasets of millions of points smoothly. Even without installing dedicated software on a PC, you can freely rotate and zoom the point cloud in a 3D viewer using a web browser to inspect details. Lack of a high-performance PC is no longer an issue.

• Easy measurement and analysis: Cloud tools often allow one-touch measurement of distances, areas, volumes, and more on uploaded point cloud data. For example, embankment or excavation volumes can be automatically calculated from point clouds. You can also analyze slope gradients and cross-section shapes on the spot, expanding the range of point cloud applications.

• Secure data management: Data synchronized to the cloud are automatically backed up and stored securely. After synchronization, it is safe to delete data from the on-site smartphone without concern, reducing the risk of data loss from device loss or failure. Because the latest data are always in the cloud, everyone accesses the same information regardless of device.

• Integration with other data: On cloud platforms, uploaded point clouds can be overlaid with design drawings and 3D models. For example, if BIM models or CAD drawings (DWG files, etc.) used in design are uploaded to the cloud, it becomes easy to compare the design model with on-site point clouds to detect deviations. Some services also provide simple editing functions in the cloud to remove noise or clean point clouds, enabling necessary processing without ever passing data through third-party CAD software.

By enabling “sharing and utilizing large point cloud data among everyone” through cloud sharing, information flow between site and office becomes markedly smoother. Huge files that cannot be attached to emails can be shared via the cloud without stress, and centrally managed data are always up-to-date and consistent. As a result, the barriers to using point cloud data are lowered, leading to improved on-site productivity.

Improved work efficiency through real-time collaboration between site and office

Workflows that share smartphone-acquired point clouds in the cloud enable real-time information collaboration between the site and headquarters/offices, allowing tasks to proceed with unprecedented speed. For example, construction managers or clients can check 3D point cloud data from the office for remote sites and immediately approve the as-built condition or issue additional instructions on the spot. Where previously the site staff would prepare a report, submit it, and a supervisor would later visit the site for confirmation, sharing data in the cloud can allow decisions and instructions to be completed the same day. This reduces the need for managers to frequently visit sites, cutting travel time and business trip costs. A single manager can simultaneously check progress at multiple sites from the office, enabling overall optimized management.

Also, because acquired data are digitally stored in the cloud from the start, it contributes to the streamlining of administrative tasks such as creating as-built management forms and surveying reports. Software exists that automatically generates cross-sections from point clouds or outputs record charts in required formats, significantly reducing the effort to prepare inspection materials and delivery documents. Thus, smartphone + cloud point cloud solutions improve not only on-site productivity but also office data processing, reporting efficiency, and quality. Transitioning to workflows in which the site and management departments share data in real time is expected to speed up projects as a whole and improve accuracy.

Simple smartphone surveying enabled by LRTK

As seen so far, leveraging smartphones and the cloud can dramatically improve on-site point cloud surveying and data sharing. One noteworthy solution gaining attention in recent years is LRTK. LRTK is a groundbreaking system that allows everything from high-precision positioning to 3D point cloud scanning, cloud data sharing, and AR display to be completed with a single smartphone. It is used by attaching a pocket-sized GNSS receiver device to the smartphone, enabling centimeter-level positioning using real-time kinematic (RTK) methods. Combined with a dedicated smartphone app and cloud service in an all-in-one configuration, it is designed so that anyone can easily acquire and utilize precise surveying data.

With LRTK, a site worker can hold an iPhone and scan the surroundings to instantly generate a 3D point cloud model with positioning coordinates. Acquired data are stored in the app and can be uploaded to the cloud and shared within the company with a single tap. For example, scanning excavation terrain at a foundation work site with LRTK allows on-site calculation and verification of excavation volumes, and the 3D data can be shared via the cloud with office engineers. Supervisors or clients in remote locations can open a 3D viewer in a web browser to check details, enabling rapid approvals and decisions. LRTK’s app also includes AR features that let you overlay uploaded design drawings or BIM models on the real site view. This makes it possible to intuitively grasp deviations between the as-built and the design model on-site and to detect and correct errors early.

Furthermore, LRTK is designed for ease of use so that people without specialized surveying knowledge can operate it. Positioning and scanning are performed by following guidance on the smartphone screen and pressing buttons, so even first-time users will find it easy to use. Simple measurement tasks that traditionally required licensed surveyors can be handled by site staff with LRTK, reducing the need to outsource or consult specialized departments and accelerating day-to-day operations while saving labor. The LRTK series is compatible with the Ministry of Land, Infrastructure, Transport and Tourism’s i-Construction initiative and is expected to be a practical solution supporting the construction industry’s DX.

In this way, LRTK enables unprecedentedly fast and high-precision simple surveying with just a smartphone. As a tool that dramatically improves on-site surveying accuracy and work efficiency, LRTK is expected to grow increasingly prominent. If you want to “make on-site point cloud data easier to use” or “try surveying with a smartphone,” it is worth considering a modern solution like LRTK.

FAQ

Q: What is point cloud data? A: Point cloud data are three-dimensional data represented by a collection of many points that make up objects or spaces. They are acquired by laser scanners, LiDAR, photogrammetry, etc., and each point includes coordinates and color information. Entire buildings or terrain can be digitally recorded, and once acquired you can later measure distances or create cross-sections as needed.

Q: Can smartphones really perform accurate 3D surveying? A: Yes, with the latest smartphones combined with auxiliary devices, high-precision 3D surveying is possible. Built-in LiDAR sensors in smartphones can capture high-density point clouds at short range, and using RTK-capable small GNSS receivers improves positional accuracy to a few centimeters (a few inches). While standalone smartphone GPS alone has errors of several meters, correction technologies can achieve accuracy approaching conventional surveying instruments. Although achieving millimeter-level precision or long-distance measurement like specialized laser scanners may be difficult in some cases, the accuracy is sufficient for many uses such as as-built verification and quantity checks.

Q: What are the benefits of sharing point cloud data in the cloud? A: Cloud sharing enables people in different locations to instantly share and view 3D data. Large point cloud files are optimized for cloud viewers and can be smoothly reviewed, and measurements and analyses can be done in a browser without dedicated software. Because the latest data are always in the cloud, there is no worry about passing files with USB drives or losing track of the most recent version. Automatic cloud backup also reduces the risk of data loss and provides security. In short, cloud sharing creates an environment where “anyone, anywhere” can utilize point cloud data, improving speed and efficiency.

Q: Can I use smartphone point cloud systems without specialized knowledge? A: Smartphone point cloud systems are designed to be easy to use even for those without specialized knowledge. Even without experience operating surveying instruments, you can complete measurements by following guided steps in the smartphone app and pressing buttons. The intuitive interface allows 3D scanning like taking a photo with your phone, and results are automatically calculated and displayed on-site, so complex data processing is not required. Some familiarization is needed, but with training site staff can competently use the system.

Q: What is needed to introduce a smartphone point cloud system? A: Basically, you can get started with a smartphone, a dedicated app, and a connection to a cloud service. LiDAR-equipped smartphones can capture denser point clouds, but even without LiDAR you can often generate point clouds from photos. For high-precision surveying, it is recommended to attach and use an RTK-capable small GNSS receiver to the smartphone. Using an integrated service like LRTK, which combines an RTK device for smartphones, an app, and cloud services, makes installation smooth because the necessary hardware and software are bundled. Internet connectivity is required, but if mobile communication is available on-site no special infrastructure is needed.

Q: Can costs be reduced compared to conventional 3D laser scanners and surveying? A: Yes, costs can often be significantly reduced. Conventional 3D laser scanners can cost several million yen or more, and their operation required skilled technicians and PC software. In contrast, smartphone point cloud systems leverage existing smartphones, and required investments such as small devices and app subscriptions are orders of magnitude lower. Reducing reliance on external surveying contractors also lowers labor costs and time. Overall, from initial investment through daily operation, total costs are typically much more economical compared to conventional methods.