Cloud-Based Orthoimage Generation for Surveying and Construction Sites – Easy, Speedy Aerial Data Utilization for Improved Operational Efficiency

Table of Contents

• What is an orthoimage?

• Traditional orthoimage creation methods and their challenges

• Orthoimage generation evolving in the cloud

• Main benefits of using the cloud

• Examples of orthoimage use in surveying and construction sites

• Conclusion

• Frequently Asked Questions

What is an orthoimage?

An "orthoimage" is an image created by stitching together aerial photographs to produce a map-like view from above. Unlike a simple aerial photo, an orthoimage has its distortions corrected, so the entire image is represented as an orthogonal projection as if viewed from directly overhead. Distortions caused by terrain relief or building heights are removed, and the scale is uniform across the whole image. For this reason, you can measure distances and calculate areas with the same sense as a map, and use the image as a high-precision background for CAD drawings or GIS software. Orthoimages are characterized by their ability to create a realistic overhead map of a site by compositing multiple photos taken by drones or other platforms using advanced image processing (photogrammetric processing).

In surveying and construction, orthoimages have attracted attention as a new tool for improving operational efficiency. They are extremely useful for grasping the overall site situation and comparing drawings with actual construction conditions. Traditionally, specialized contractors created maps from photos taken by aircraft, but with the recent spread of drones, aerial photography has become easy and orthoimage generation and utilization have become much more accessible. The next section looks at the conventional methods for creating orthoimages and the challenges involved.

Traditional orthoimage creation methods and their challenges

To create orthoimages from photos taken by drones or aircraft, the conventional approach mainly used PC-based photogrammetry software (photogrammetry tools). First, a large number of aerial photos are imported into specialized software, which matches feature points between photos for alignment, corrects distortions, and mosaics them together. While this method can produce high-accuracy orthoimages, there were several major hurdles for small and medium surveying and construction sites to adopt it. The main challenges are summarized below.

• Requirement for high-performance PCs and expensive software: The processing to analyze large numbers of images and synthesize orthorectified images is very computationally intensive. Therefore, handling tens to hundreds of photos required expensive workstation-class high-performance PCs or machines equipped with GPUs. The software itself is often specialized and comes with high license fees, making the upfront cost a significant burden if frequent use is uncertain.

• Long processing times and effort: After returning to the office and importing large numbers of photos into a PC, it often took a long time for the analysis to finish. In some cases, a PC would run overnight and the orthoimage would only be complete the next day. The PC could not be used for other tasks during processing, which is inefficient, and optimizing analysis settings required expert knowledge, making it a high barrier for beginners.

• Burden of data management and sharing: Finished orthoimage data are high-resolution and therefore large in file size, sometimes reaching several hundred MB to several GB. They could not be sent via email attachments and had to be transferred via external storage services or hard disks. Keeping the latest data shared among multiple stakeholders was laborious and risked mistakes such as using outdated versions.

• Additional tasks and peripheral work: To practically use an orthoimage, additional tasks may be required, such as importing into drawings, aligning positions, and checking scales. For example, when using an orthoimage as a background in CAD, you may need to align coordinate systems or trim unwanted parts. Also, orthoimages alone do not provide height information, so for volume calculations or cross-section creation you must generate point cloud data or elevation models separately, and reconciling and adjusting these requires specialist skills.

As described, traditional orthoimage creation had many issues in terms of time, cost, and effort. Even if aerial data were collected with a drone, delays in processing and sharing prevented quick on-site response. This led to a new approach: orthoimage generation that leverages the cloud.

Orthoimage generation evolving in the cloud

Recently, methods that use internet-based cloud services to generate orthoimages have gained attention. "Cloud-based orthoimage generation" refers to services where users upload aerial photos via a browser, and cloud servers automatically analyze the photos to create orthoimages, 3D models, and more. The major feature is that users do not need to worry about heavy computational processing and can handle large numbers of photos without a high-performance PC on hand.

The basic workflow of cloud services is simple. First, prepare the many photos taken by a drone and upload them via a dedicated web page. Then advanced photogrammetric algorithms run on cloud servers to match feature points between photos and reconstruct the ground surface in 3D. Concurrently, image distortion correction and mosaic compositing are performed, producing an accurate orthomosaic image. When processing is complete, users can preview the resulting orthoimage on the cloud or download the file.

What’s important is that all these heavy processes run on the cloud, so the user’s PC load is very small. You can upload from a laptop or tablet at the site and have the analysis finished by the time you return to the office. There is no need to manage or install software locally, and you can always use the latest processing engine. It has become an era where high-precision results can be obtained by simply "throwing the photos into the cloud."

Main benefits of using the cloud

Switching to cloud-based orthoimage generation resolves the previously mentioned challenges and provides many benefits. The main advantages are as follows.

• Significant time savings: Because powerful servers perform parallel calculations, processing time is dramatically reduced. For example, orthoimage generation that used to take half a day can, on the cloud, often be completed in tens of minutes to about an hour. If you perform drone photography in the morning and upload to the cloud, you may have completed data as early as the same day. Quick sharing of results enables immediate verification of survey outcomes and prompt consideration of subsequent steps, speeding up the entire project.

• No need for high-performance PCs: Users only need a PC with general specifications and do not have to invest in specialized hardware. With calculation resources provided by the cloud, there is no need to purchase expensive workstations or GPU machines for in-house use. Each employee can use their own PC, allowing flexible orthoimage generation from the office or on the go.

• Labor savings through automation: After uploading photos, processing is automated and there is no need to manually set detailed parameters. The service optimizes difficult analysis conditions, so the person in charge only waits for results. There is no need to install software or manage versions, and the latest features are always available. Tasks that used to require expert operators become straightforward, allowing on-site technicians to handle them and preventing work from becoming dependent on specific individuals.

• Centralized management and sharing of large data: Orthoimages and related data can be stored in the cloud, organized and accumulated by project. Some services offer unlimited storage capacity, allowing safe storage of past survey data. Granting access rights to stakeholders enables them to view and use the same latest data remotely. There’s no need to carry USB drives or send large files by email anymore.

• Backup and security peace of mind: Cloud services handle data backup and redundancy, so even if a user’s PC fails, there is no worry about data loss. Communications are encrypted and access rights are carefully managed, so high-confidentiality survey deliverables can be safely entrusted to the cloud. In some cases, this is more reliable than hosting servers in-house, offering benefits in information security as well.

By leveraging the cloud, you can achieve not only direct effects such as time and cost reduction but also risk reduction through secure data management and streamlined workflows. This new approach using the latest technology offers many advantages and is a highly valuable solution compared to traditional methods.

Examples of orthoimage use in surveying and construction sites

With cloud-based, easy-to-produce accurate orthoimages, a variety of applications in surveying and construction become possible. Below are some representative use cases.

• Grasping current conditions and streamlining drawing creation: Orthoimages provide an ideal overhead view for understanding the overall site situation. They allow you to grasp the layout of terrain and structures at a glance, which previously required time-consuming ground surveys. The obtained orthoimage can be used directly as a plan view or as a base layer for CAD drawings, enabling accurate drawings that reflect the latest site conditions. For example, in as-built management, you can overlay the orthoimage as a background to check whether the completed structure matches the design.

• Earthwork volume calculations and cross-section creation: While orthoimages do not include vertical height information, when combined with 3D point cloud data or digital surface models (DSM) that can be generated simultaneously by cloud services, they become powerful for volume and cross-sectional analysis. You can calculate volumes of fill and cut, create longitudinal and transverse sections at arbitrary locations, and use them for earthwork planning. Some services allow you to designate a cross-section line in the cloud viewer and immediately output a cross-section (DXF format), greatly streamlining previously complex surveying calculations.

• Construction management and progress records: By conducting periodic drone flights and creating orthoimages, you can record and share construction progress over time. Comparing terrain changes and completed quantities weekly or monthly helps detect delays and issues early. Unlike photos, orthoimages always use the same scale, making differences from previous data intuitively visible and useful for sharing progress among all stakeholders.

• Safe surveying of hazardous areas: Drones can safely collect data in hazardous locations such as steep slopes or riverbeds where it is dangerous for people to enter. Using the resulting orthoimages, you can quickly perform surveys of hazardous areas, determine the extent of collapses, and perform other assessments without relying on manual surveying. Orthorectified images are also effective immediately after disasters to determine affected areas and estimate damage amounts in a short time, aiding initial response and recovery planning.

• Information sharing among stakeholders: Orthoimages stored in the cloud are easy to share among stakeholders. By issuing a link, recipients can view images in a browser without specialized software. There is no need to send large files individually, and project owners, designers, contractors, and administrative officials can all review the same latest ortho map together. This eliminates misunderstandings and enables smooth collaboration without communication losses.

In this way, cloud-generated orthoimages become a powerful data foundation applicable across surveying, design, construction, and maintenance. In the construction industry’s DX movement, represented by the Ministry of Land, Infrastructure, Transport and Tourism’s "i-Construction," efficiency improvements using drones and orthoimages are becoming indispensable. By adopting the latest technologies on site, you can achieve smart construction that balances safety and productivity.

Conclusion

The method of "quickly generating high-precision orthoimages in the cloud from photos taken by drones" is becoming the new standard in the surveying and construction industries. Cloud services that allow you to obtain reliable overhead maps of sites in a short time without high-performance PCs or complex expertise are set to transform conventional surveying and drawing workflows. Professionals such as civil engineering supervisors and surveyors, as well as designers, project owners, and municipal staff—anyone who needs survey data—can benefit.

Utilizing aerial data for efficiency will only grow in importance. If you have not yet introduced drones or cloud analysis, this is a good opportunity to incorporate the latest technology into your workflow. It is possible to introduce them in stages—starting with small projects to get used to the operation before full deployment. Make easy, speedy orthoimage generation your ally and take a step forward in the DX of surveying operations.

Frequently Asked Questions

Q: If I have photos taken by a drone, can anyone create an orthoimage? Is specialized skill required? A: Yes, as long as you can prepare aerial photos, anyone can basically generate an orthoimage. Cloud-based photo analysis services are designed to be usable by non-experts; you just follow the web interface prompts to upload images and processing proceeds automatically. You can obtain results without understanding difficult theories or parameter settings, so even those new to drones or surveying can feel confident. Choosing a domestically produced service also means Japanese manuals and support are often available, so you can quickly resolve any operational questions. In practice, a wide range of professionals—from field surveyors to construction managers and designers—have begun adopting these cloud services.

Q: Can I use a regular consumer drone I already own? Do I need expensive specialized equipment or a surveying drone? A: Ordinary aerial drones are generally sufficient and special equipment is not required. Photos taken with commercially available drones can be uploaded to the cloud and analyzed without issue. If you want higher accuracy, including ground control points (GCPs) in your photos at flight time allows the cloud service to automatically apply positional corrections and improve accuracy. Recently, RTK-enabled drones have become available; by using a GNSS receiver built into the aircraft or transmitter during shooting, you can acquire images with high-precision position information. Many cloud services support these high-precision options, so it’s a good idea to start with your current drone and incorporate accuracy-enhancing methods as needed.

Q: How can generated orthoimages and point cloud data be used? A: Orthoimages and related 3D point cloud data have a wide range of uses. As mentioned, orthoimages can be used as background maps in CAD to check as-built conditions or pasted into reports as current-condition images, aiding verification and presentation during design and construction. Point cloud data can visualize site elevation differences and automatically generate cross-sections at arbitrary locations for comparison with design drawings. Measuring distances, areas, and volumes on point clouds can be applied to volume calculations and progress management. Digitally storing the acquired data also serves as useful reference for future renovations and infrastructure maintenance. In short, orthoimages and 3D data obtained from a single drone survey provide value across surveying, design, construction management, and maintenance.

Dramatically improve on-site survey accuracy and efficiency with LRTK

If you are thinking "I want to practice easier, more accurate on-site surveying," there is a solution called "simple surveying with LRTK." By using the LRTK series, you can upload photos taken by a drone to the cloud and automatically generate high-accuracy point cloud data with absolute coordinates, obtaining orthoimages and cross-sections in one workflow. Its ease of use for non-experts and the comprehensive support from domestic manufacturers make it easy to introduce on-site even for those with limited surveying experience. Combining high-precision GNSS positioning technology with cloud image analysis, LRTK can accelerate on-site DX in a way that aligns with the Ministry of Land, Infrastructure, Transport and Tourism’s "i-Construction" initiative. Why not adopt cutting-edge technology and start smart surveying that goes beyond conventional norms?

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