Cloud processing for labor-saving on site! Drone surveying without high-spec PCs

Table of contents

• Challenges of drone surveying

• What is a cloud processing service

• Benefits of cloud processing

• Deliverables and functions that can be generated

• Use cases in construction and surveying

• Simple surveying using LRTK with a smartphone

• FAQ

Challenges of drone surveying

In recent years, 3D surveying using drones has been attracting significant attention in the construction industry as part of *digital transformation (DX)*. Supported by the Ministry of Land, Infrastructure, Transport and Tourism's *i-Construction* initiative, efforts to utilize data obtained by photographing sites from above are progressing. If you generate three-dimensional point cloud data (a model that represents the surface shape of an object with many point coordinates) from photos taken by a drone, you can accurately measure terrain and structures and use the results for as-built management and volume calculations. Compared with traditional manual surveying, it can capture current conditions over a wide area in a short time, making it a technology that greatly reduces on-site labor.

However, until now, creating high-precision 3D models from drone photos has required high-performance PCs and expensive dedicated software. For example, if you try to operate photogrammetry (SfM analysis) software in-house to generate point cloud data from photos, the initial investment of hundreds of thousands to millions of yen can be a heavy burden. In many cases, organizations that cannot provide high-spec PCs end up simply viewing the captured photos without taking the step to create 3D models.

In addition, processing over 100 high-resolution images to generate point clouds requires long computation times, during which the PC is tied up. While analysis is running, other work cannot be done, lowering productivity. Operating photogrammetry software and setting parameters also require specialized knowledge, and it can be difficult to handle without experienced technicians in-house. As a result, many companies have given up on creating detailed terrain models and calculating volumes by drone on their own and have been forced to outsource to external surveying firms.

When outsourcing, analysis can take several days to complete and costs can add up. On the other hand, if you can process data quickly in-house, you could confirm results on the same day the drone captured the images and use them to inform next steps. To meet the demand for “easily performing drone surveying data processing,” new solutions have emerged.

What is a cloud processing service

What has recently emerged is a cloud-processing drone surveying data analysis service. In Japan, cloud services are beginning to be offered that automatically generate 3D point cloud data and other outputs simply by uploading aerial photos taken on site to an online platform. By using these services, you can perform advanced data analysis easily without purchasing dedicated high-spec PCs or software.

The workflow is very simple. Access the service website via a web browser and upload the drone-captured photo data. Then the photogrammetry analysis is automatically executed on high-performance servers in the cloud. The analysis matches common points across multiple photos and calculates the 3D coordinates of each point using the principles of triangulation (the so-called *Structure from Motion* technology). Even datasets of hundreds of photos can be processed efficiently by parallel processing on the server side, and in some cases results can be obtained in less time than traditional PC-based processing. Once processing is complete, output data such as 3D point clouds and orthomosaic images are made available on the cloud, and users can view and download them via a browser. Because heavy computations do not need to be performed on a local PC, you can continue other tasks while analysis runs, avoiding a drop in work efficiency.

Also, cloud services provide workflows optimized for analysis, so users do not need to perform difficult configurations. As long as basic shooting quality such as the number of photos and overlap is ensured, high-quality point cloud data can be obtained without expert knowledge. By leveraging the cloud, advanced data processing for drone surveying is becoming much more accessible.

Benefits of cloud processing

There are many advantages to performing drone surveying data analysis in the cloud compared with traditional local PC processing. The main benefits are summarized below.

• Reduced initial cost: Since there is no need to purchase high-performance PCs or expensive analysis software, capital investment can be greatly reduced. Previously, introducing workstations and software could cost hundreds of thousands to millions of yen, but removing that burden makes adoption easier for small and medium-sized enterprises.

• Reduced load on local PCs: Because large-volume photo processing can be executed in the cloud, there is no worry that your PC will be frozen for a long time. You can proceed with other tasks in parallel and be freed from the stress of long processing waits.

• High-speed processing and scalability: Powerful servers and parallel processing in the cloud allow heavy analyses to complete quickly. Large numbers of photos or large survey areas are not a problem. For example, analyses that would take more than half a day on a normal PC may finish in a few hours in the cloud. The cloud also offers flexibility such as processing multiple site datasets in parallel within a single company.

• Usable anywhere: Because the service is accessible via the internet, you can upload data and check results from the office, the field, or while on the go. For example, you can send photo data to the cloud immediately after shooting on site and have analysis progress while traveling, so results may be ready by the time you return to the office.

• Easy data sharing: Generated point clouds and orthomosaic images are stored in secure cloud storage, making it easy to share online with stakeholders or view collaboratively. Large datasets are accumulated in the cloud and do not consume local disk space. Also, without installing dedicated viewers on each PC, 3D data can be visualized directly in the browser.

• Always enjoy the latest technology: Since the service provider continuously updates analysis algorithms and features, users can always use the latest analysis technology. Improvements in accuracy and new functions are automatically applied with updates, so users do not need to perform cumbersome software updates.

• Comprehensive support: For domestic cloud services, you can receive thorough support and implementation assistance in Japanese, providing peace of mind. You can quickly consult about operation questions or troubleshooting, so even beginners can start using the service with confidence.

Deliverables and functions that can be generated

Cloud-based drone surveying services automatically create a variety of deliverables useful for surveying and design, not just point clouds. Representative outputs are listed below.

• 3D point cloud data: Generate dense colored point clouds from multiple photos taken by a drone. By combining positioning information from RTK-enabled drones and ground control points, high-accuracy point clouds with absolute coordinates assigned to each point can be obtained. Generated point cloud data can be exported in standard formats (such as LAS) for use in other CAD software or analysis tools.

• Orthomosaic images: Stitch multiple aerial photos covering a wide area to create distortion-free orthophotos (true-orthographic images). These overhead-view images provide a bird's-eye perspective and include coordinate information, making them usable as survey plan views.

• Digital Surface Model (DSM) and contour lines: Extract surface elevation data from generated point clouds and automatically create gridded DSMs (Digital Surface Models) and contour maps at chosen intervals. These outputs can be used directly as topographic maps and are helpful for grading plans and drainage design.

• Various measurement functions: On the cloud point cloud viewer, you can measure distances between any two points, areas of enclosed regions, and calculate volumes, elevation differences, and slopes. For example, the volume of an embankment can be automatically calculated by setting a reference plane on the point cloud. Even without special CAD software, you can quickly read the required dimensional information on the web, improving efficiency in report preparation.

• Cross-section generation (DXF output): Extract cross-sectional shapes along arbitrary section lines from point cloud data and output them as CAD drawings. Generated cross-sections can be downloaded in DXF format and used directly for comparison with design drawings or in as-built reports.

• Overlay with design data: Overlay design models or drawing data on 3D point clouds to visualize differences between the as-built condition and design plans with color-coding. The service supports outputting color difference maps recommended by the Ministry of Land, Infrastructure, Transport and Tourism's as-built management guidelines (draft), helping to quickly identify construction defects. By intuitively showing deviations between the finished form and the as-built condition with colors, construction management and inspection tasks are strongly supported.

Use cases in construction and surveying

Cloud-complete drone surveying solutions are expected to be applied across various industries and uses. They are likely to be especially effective in the following fields.

• Construction and civil engineering: Using drone surveying for as-built management and volume calculations on construction sites can improve site management efficiency and reduce labor. For example, calculating embankment and excavation volumes from point clouds captured by drone during earthworks enables rapid and accurate progress management and as-built reporting. As-built measurements that previously took several days by hand can be completed the same day from drone shooting to cloud processing, enabling swift decision-making. This 3D surveying method also aligns with the Ministry of Land, Infrastructure, Transport and Tourism's *i-Construction* initiative and promotes DX (digital transformation) on construction sites.

• Surveying companies and construction consultants: Being able to create 3D deliverables quickly and at low cost improves operational efficiency and strengthens service competitiveness. Without owning expensive workstations or software in-house, large-scale surveying project data processing can be entrusted to the cloud, enabling shorter delivery times and cost reduction. Automated processing also stabilizes data quality, allowing less-experienced technicians to produce high-quality deliverables.

• Municipalities and public agencies: In infrastructure inspections and disaster response, quickly converting drone-acquired condition data into 3D models dramatically improves situation awareness and decision-making speed. Simply sending photos taken on site to the cloud can yield detailed terrain models and orthophotos within a few hours, making them immediately useful for assessing damage or managing facilities. For example, even in the case of a large landslide, drones can record the situation from above and the volume of collapsed soil can be calculated the same day to inform restoration planning. Municipalities without specialized departments will find more opportunities to respond in-house rather than outsourcing.

• Other fields: Applications are expanding to agriculture and forestry for surveying fields and forests from above, and to education and research for easily creating 3D models. From vast measurement areas to hazardous zones where people cannot enter, drone × cloud surveying can be applied to various fields depending on the idea.

Simple surveying using LRTK with a smartphone

In addition to cloud-based drone data analysis, smartphone-based simple surveying is attracting attention as a means to perform 3D surveying easily on site. Our LRTK Phone offers a groundbreaking system that enables 3D surveying with centimeter-level accuracy (half-inch accuracy) using only a smartphone. By attaching a dedicated small antenna to a smartphone and combining high-precision GNSS positioning with the built-in LiDAR scanner and camera, a single person can easily acquire high-precision point cloud data. Simply launch the dedicated app and walk the site holding the phone, and 3D point cloud generation is completed on the spot.

For example, areas that are difficult for drones to capture, such as the underside of bridges or the ground surface inside forests, can be scanned in detail simply by walking with the LRTK Phone in hand. Since the obtained ground point cloud data have absolute coordinates, they can be automatically integrated with airborne point cloud data generated by drones. By complementing drone-captured blind spots with smartphone measurements, you can achieve more comprehensive condition assessment.

Also, for routine simple measurements, you can complete the task with just a smartphone without flying a drone. Because you can quickly acquire 3D data on site when needed, productivity will greatly improve at sites where surveying tasks are frequent. By using cloud drone point cloud services and LRTK Phone according to the application, you can establish a seamless workflow that covers everything from wide-area mapping to detailed measurements in confined spaces.

Thus, with the emergence of cloud-complete services and smartphone surveying technologies, 3D surveying using drones is becoming even more accessible. Why not introduce a new workflow on site that is not dependent on high-spec PCs and ride the wave of DX? You will be freed from cumbersome PC-based analysis tasks and able to use on-site data more quickly. Our LRTK platform robustly supports your surveying workflow reform through these cutting-edge technologies. Cloud analysis technologies are advancing rapidly, and our LRTK platform also plans further feature expansion in the future. Actively adopt the latest technologies and realize on-site labor savings and productivity improvements.

FAQ

Q: What kind of users is this service suitable for? A: It is suitable for a wide range of people who want to use 3D data from drone surveying, including construction site engineers and civil surveying staff, construction consultants who handle spatial data, and municipal staff involved in infrastructure management. Small operators without a dedicated department can easily introduce the service, so it is recommended for any site that wants to make effective use of drones. It is also useful for individual drone operators and small businesses as a cost-effective way to achieve advanced 3D surveying.

Q: What deliverables can I get by using the service? A: You will automatically receive 3D point cloud data (colored point clouds), high-resolution orthophotos (overhead images), digital surface models (DSM) and contour maps, cross-sections (DXF format), and other deliverables needed for surveying and design. Various measurements (distance, area, volume, etc.) can be performed on the acquired data, so the outputs can be used widely from site assessment to report preparation.

Q: How long does the analysis take? A: It depends on the number of photos and cloud server congestion, but as a guideline, point cloud generation for about 100 photos often completes in around one hour. Large-scale projects with around 500 photos can be processed in a few hours to half a day. Generally, you can obtain results on the same day of shooting, and you can acquire 3D models much more quickly than with PC-only processing.

Q: Do I need special equipment or software to start using the service? A: All you need is a general PC (or tablet), an internet connection, and a drone body. Cloud services are accessible via web browsers, so there is no need to install dedicated software. As long as the browser runs on your OS—Windows or Mac—you can use the service without a high-spec PC (all processing is performed on the server side).

Q: Can I use any drone? A: In principle, photos taken with commercially available aerial drones can be analyzed regardless of the model. However, drone camera performance and shooting methods are important for high-quality point cloud generation. Take high-resolution, sharp photos with sufficient overlap to achieve accurate models. Using an RTK-equipped drone improves positioning accuracy, which in turn raises the surveying accuracy of the generated point cloud data.

Q: How accurate is the surveying accuracy of the generated point cloud data? A: Accuracy varies depending on drone GPS accuracy, flight altitude, and whether ground control points are set. Even with a standard GPS-equipped drone, relative errors of several centimeters to around a dozen centimeters (several in to around a dozen in) can be achieved under good conditions, which is practically sufficient for many uses. By using RTK-enabled drones and ground control points, errors can be reduced to within a few centimeters (within a few in). With appropriate accuracy control, the results can meet the quality level to be used as deliverables compliant with the Ministry of Land, Infrastructure, Transport and Tourism's "3D Surveying Guidelines."

Q: Do I need specialized knowledge or skills to operate it? A: No. As long as you understand the basic procedure for uploading photo data, advanced analysis is automatically executed in the cloud, so image analysis expertise is unnecessary. The interface and manuals are available in Japanese and are designed to be intuitive, so even first-time users can operate smoothly by following the guides. If you have questions, our support team will provide careful follow-up, so you can start using the service with confidence.

Q: I'm worried about entrusting data to the cloud. Is security adequate? A: This service implements robust security measures for communications and data storage. Uploaded photos and generated point cloud data are encrypted and safely stored on cloud servers. Access rights can be set for each user, so only authorized members within your organization can view the data. The cloud servers are operated in reliable domestic data centers, so you can use the service with confidence even for projects requiring confidentiality.