Dramatic Improvement in Work Efficiency with Ortho Generation! Why Civil Engineering Sites Are Changing

Table of Contents

• Introduction

• What Is Ortho Generation?

• Traditional Surveying Work and Its Issues

• Key Points Where Ortho Generation Dramatically Improves Efficiency

• Use Cases: How Ortho Images Are Changing Civil Engineering Sites

• Conclusion

• Simple Surveying with LRTK

• Frequently Asked Questions

Introduction

Surveying existing conditions and recording as-built results are routine tasks at civil engineering and construction sites. However, traditional methods for performing these tasks accurately have required a great deal of time and labor, posing a major challenge for an industry suffering chronic labor shortages. For example, understanding the terrain of a large development site used to require multiple survey staff to be dispatched to measure each point with a total station and produce drawings. Surveying on hazardous slopes or in areas with poor footing also raises safety concerns. Against this backdrop, a technology attracting attention in recent years is “ortho generation.” By using ortho images (aerial photographs orthorectified) obtained by photographing the site from above with drones and the like, site measurements that once took days can now be made dramatically more efficient. In addition, with initiatives such as the Ministry of Land, Infrastructure, Transport and Tourism’s *i-Construction* promotion, ortho generation is garnering high expectations as a trump card for improving on-site productivity. This article explains why ortho generation dramatically improves work efficiency and explores how civil engineering site workflows are changing.

What Is Ortho Generation?

An ortho image is created by stitching together a large number of photographs taken from the air, correcting distortions so the image appears as if viewed directly from above. In simple terms, it is a “map-like photograph of the site seen from the air,” characterized by accurate reflection of dimensions and distances. Because it corrects for tilt and distortion caused by buildings and terrain, scale on an ortho image is treated the same as on a map. The process of creating these ortho images is called ortho generation. In practice, multiple photos taken by a drone or similar device are used to reconstruct a 3D model (point-cloud data) on a computer, and that model is then projected as a top-down view to synthesize the ortho image. Traditionally, orthorectification was performed using specialized aerial-photography software, but recent advances in photogrammetry algorithms have enabled highly detailed ortho images to be generated automatically in the cloud. We have entered an era in which detailed plan-view images of existing conditions can be obtained in a short time simply from aerial photo data—without needing to measure many points with special surveying equipment.

Traditional Surveying Work and Its Issues

To understand the efficiency gains from ortho generation, let’s summarize the problems inherent in conventional site surveying. It used to be standard practice to投入大量の人力と時間 when producing terrain drawings. Typically, surveying would be performed by two-person teams using total stations to record position coordinates point by point. Back at the office, those points would be connected in CAD software to finally complete a plan. This method had the following issues:

• Time-consuming and labor-intensive work: Because surveying requires teams of two or more to set up and move equipment, surveying large areas often took a full day or more. Personnel had to be allocated from other tasks for surveying, which tended to affect overall project schedules.

• Human error and missed measurements: Because humans measure each point individually, there is a risk of read errors or recording mistakes. Also, only a limited number of points can be measured, making it difficult to fully capture complex terrain changes. Discovering “forgotten measurements” later and having to perform additional surveying is inefficient.

• Heavy equipment and safety issues: Survey equipment such as total stations are large and require effort to transport and set up. High-precision measurements require solid mounting, limiting mobility. Workers often have to enter hazardous slopes or survey on roads with vehicle traffic, necessitating careful safety management.

• Specialized knowledge and experience: Accurate surveying and drafting require specialized skills, placing a heavy burden on veteran workers. For newcomers, operating equipment and handling data processing can be difficult, and training takes time.

As described above, traditional surveying methods posed many efficiency and safety challenges. Meanwhile, the construction industry has recently faced worsening chronic labor shortages and an aging workforce, making it urgent to pursue labor-saving and efficiency improvements to operate sites with limited personnel. Industry-wide DX efforts to improve productivity—such as the *i-Construction* initiative advocated by the Ministry of Land, Infrastructure, Transport and Tourism—are accelerating, and fundamental reforms through digitization and automation of surveying work are being sought.

Key Points Where Ortho Generation Dramatically Improves Efficiency

How does adopting ortho generation solve the above problems? Here are the main benefits.

• Major time savings: Automatic aerial photography by drone and cloud-based image analysis can reduce site measurements that previously took half a day to several days to just tens of minutes to a few hours. High-precision ortho images and 3D data can be obtained on the same day of shooting, enabling immediate progression to the next work stage and shortening overall project duration.

• Fewer people and safer operations: Because the site is photographed from above, people do not have to enter hazardous areas. One drone and an operator can cover large areas, and work in harsh conditions such as at night or on extremely hot days is minimized. As operation can be performed by a single person, single-person surveying becomes feasible, allowing surveying to proceed even at sites with personnel shortages. Remote data acquisition for high places or high-traffic areas also helps reduce accident risk.

• Comprehensive data and improved accuracy: Ortho images and point-cloud data capture information about all parts of the site. The worry of “missed measurements” is greatly reduced, allowing comprehensive recording of site conditions at the time of shooting. Furthermore, combining RTK-equipped drones or ground control points (GCPs) can provide absolute accuracy within a few centimeters (within a few inches). Photogrammetry algorithms themselves have also advanced, and with proper procedures, accuracy comparable to traditional ground surveying can be achieved.

• Immediate automatic generation of diverse deliverables: Using cloud services, the process that generates a point-cloud model from photos also automatically outputs an ortho mosaic image. Functions are emerging that allow you to extract arbitrary cross-sections from the obtained 3D data and download them in DXF format. With a single data acquisition you can obtain ortho images, point clouds, cross-sections, and quantity calculation results all at once, largely eliminating additional surveying and manual drafting. Creating terrain models and drawing contour lines or texturing 3D models for visualization becomes easy. This reduces the burden on engineers and directly speeds up as-built management and report preparation.

• Data sharing and faster decision-making: Digital data can be stored and shared in the cloud, enabling real-time information sharing between field and office. You can review ortho images with supervisors or clients immediately after surveying, and stakeholders in remote locations can confirm results via a browser. Compared to traditional methods of paper drawings or carrying files on USB, this realizes far faster and more reliable information sharing and speeds up decision-making. Always sharing up-to-date data reduces rework and mistakes, ultimately contributing to improved quality and safety.

Use Cases: How Ortho Images Are Changing Civil Engineering Sites

Let’s look at concrete examples of how introducing ortho generation changes site work.

At one development site, terrain surveying that previously required 2–3 people and more than half a day was replaced by drone aerial photography, allowing completion with one person in about one hour. Point-cloud data and ortho images were automatically generated in the cloud immediately after shooting, and a detailed existing-condition map was produced the same day. At the same time, the volumes of fill and cut were automatically calculated, and the differences from design data (excesses and shortages of earthwork) were computed instantly. This is an excellent example of significantly improving surveying and drafting efficiency while reducing manpower.

In another case, ortho images from drones are being used for as-built management on a large dam construction project. The process that used to involve measuring many sections, calculating earthwork volumes, and manually drafting drawings has been transformed: regular drone flights and cloud processing now allow rapid completion from site assessment to quantity calculation. Because the obtained point-cloud data are positioned in a global coordinate system, data captured later can be easily integrated, and drawings reflecting the latest conditions can be updated quickly as needed. This minimizes losses from having to remeasure missing areas later and enables faster on-site decision-making.

As shown, the introduction of ortho images and point-cloud data is beginning to fundamentally change conventional site practices. Surveying and measurement tasks that used to take time and effort are being streamlined and accelerated through digital tools, enabling limited personnel to safely and reliably grasp site conditions. Using the detailed data obtained for construction management and maintenance also leads to improved overall project quality and cost reduction. Ortho generation can be considered a “game changer” that fundamentally transforms workflows at civil engineering sites.

Conclusion

The spread of ortho generation technology is dramatically improving work efficiency in the civil engineering industry. By digitizing surveying tasks that used to rely on manpower, sites can now understand conditions quickly, accurately, and safely. This is not only convenient but also a significant advance that directly contributes to shorter schedules, cost reductions, improved working conditions, and securing younger talent. With national DX initiatives supporting adoption, smart construction using ortho images and point-cloud data is likely to become standard practice going forward.

Some may worry whether their company can actually adopt these advanced technologies. However, recent cloud services and surveying solutions are designed to be usable without specialized knowledge. With a few key points in mind, they can be easily introduced on any site. The efficiency gains benefit everyone from field staff to management and lead to workplace reforms across the site. Combining ortho generation with AI-based automatic analysis is expected to enable even faster and more sophisticated surveying. The digital surveying revolution centered on ortho generation is already reshaping conventional practices. Moving forward with flexible thinking beyond traditional methods will be essential for the construction industry.

Simple Surveying with LRTK

For those who want to realize ortho-generation-driven efficiency on their own sites, the LRTK series offers a recommended simple surveying solution. LRTK consists of an ultra-compact RTK-GNSS receiver that can be attached to a smartphone and a cloud service, enabling anyone to perform centimeter-level positioning (half-inch-level positioning) and 3D measurement easily. Simply upload photos taken by a drone to the cloud and a high-precision point-cloud model is automatically generated, allowing you to obtain ortho images and cross-sections all at once. No specialized high-performance PC or complicated operations are required, and data shot on site can be immediately turned into deliverables. LRTK also supports smartphone-based point-cloud scanning (LiDAR), allowing easy supplementation of detailed areas that drones cannot see, such as the back sides of structures or under trees. The LRTK series is produced by a domestic manufacturer compatible with *i-Construction* and provides comprehensive support from introduction through operation, so it can be used with confidence even by non-experts. Leverage cutting-edge surveying technology to powerfully drive productivity improvements and DX at your site with LRTK.

If you are interested, please feel free to contact us. LRTK will help evolve your site to the next stage.

Frequently Asked Questions

Q: What equipment and software are needed to generate ortho images? A: Basically, you can get started with a drone equipped with a high-resolution camera and an Internet connection. Capture aerial photos of the site with a drone and upload the image data to a cloud service; you can then generate point clouds and ortho images without purchasing expensive software or a high-performance PC. For higher accuracy, use an RTK-capable drone or place multiple ground control points (targets). A computer to view the processed results only needs to support a standard web browser.

Q: How reliable is the accuracy of ortho images and point-cloud data? A: Accuracy varies with shooting conditions and equipment, but with proper operation, accuracy comparable to traditional ground surveying can be achieved. Ensuring sufficient photo overlap and performing position correction with an RTK-equipped drone or ground control points (GCPs) can yield high-precision results with errors on the order of a few centimeters (a few inches) in both plan and elevation. Even non-RTK drones can produce models with high relative accuracy using photogrammetry algorithms alone, but if precise coordinates are required, simple ground control points are recommended for correction. In any case, the accuracy is generally sufficient for normal construction-management uses.

Q: Is it safe to store surveying data in the cloud? A: Many cloud services take comprehensive measures for security and data protection. Communications are encrypted, and servers implement access control and intrusion prevention measures, so sensitive surveying data can be stored with confidence. Automatic backups mean that even if the user’s PC fails, data remain in the cloud. When selecting a service, review the terms of service and privacy policy and choose a reputable provider.

Q: Do I need specialized knowledge to introduce this? Can beginners use it? A: Recent ortho generation services are designed to be user-friendly for beginners. The basic procedure is simply to take photos on site and upload them to the cloud. Advanced parameter settings are automatically adjusted in the background, so you can obtain results without understanding complex theory. Choosing a service with Japanese manuals and support desks allows you to ask questions when unsure. There are many cases where newcomers to drones or surveying have successfully adopted the technology; a phased approach—trying small projects first and scaling up as you become familiar—is possible.

Q: Is the cost of introducing ortho generation worth it? A: Initial investment is required for drone platforms and cloud service subscriptions, but the benefits usually justify the cost. Labor and days previously spent on conventional surveying and measurement are greatly reduced, so mid- to long-term efficiency gains often exceed the investment. Additionally, reduced high-altitude work lowers the risk of occupational accidents, and rapid data acquisition shortens project schedules—effects that are hard to quantify but significant. Demonstrating the use of the latest technology can also be an advantage when bidding, improving competitiveness. Overall, ortho generation is generally cost-effective. Recent reductions in small-drone prices and wider availability of cloud services have also lowered barriers to entry.

Q: How can the generated ortho images and point-cloud data be used? A: Ortho images can be used as a base for CAD drawings in place of plan-view surveys to check whether as-built shapes match design. From point-cloud data you can create cross-sections at arbitrary locations and compare them with design data to verify construction errors. Measuring distances, areas, and volumes on the point cloud helps calculate earthwork quantities and manage construction progress. Regularly obtaining ortho images enables monitoring terrain changes and progress over time. In large-scale disasters, ortho images and point-cloud data are used to assess damage and plan recovery. The generated 3D models can also be imported into CG software to create presentation materials for stakeholders, so the range of applications is very wide. Thus, ortho images and point-cloud data can be used across surveying, design, construction management, and maintenance.