Cloud-Integrated Survey Data Sharing! Network RTK: the Information Source Connecting Field and Design

Table of Contents

• What is Network RTK

• Benefits Network RTK Brings to the Field

• Survey Data Sharing Expanded by Cloud Integration

• A New Workflow Connecting Field and Design

• Summary

• FAQ

What Is Network RTK

In recent years, improving productivity on surveying sites by leveraging the cloud and GNSS technologies has become a major theme. This article focuses on "network RTK," the key to enabling survey data sharing via cloud integration, and explains its mechanism and effects.

In construction and surveying, even a position offset of a few centimeters can greatly affect outcomes. In infrastructure projects such as highways and railways, and in civil works like pile driving or as-built control, small positioning errors can compromise quality and safety. For that reason, RTK (real-time kinematic) technology, which corrects satellite positioning errors in real time to obtain high-precision positions, is essential.

Standalone GNSS (GPS) positioning typically yields errors on the order of meters. By using RTK, correction information from a reference station is applied in real time, enabling immediate positioning with centimeter-level accuracy. Achieving high-precision real-time positioning contributes significantly to streamlining field work and reducing labor in surveying. This technology is also indispensable as the foundation of the recently promoted i-Construction (ICT-based construction).

RTK positioning is a relative positioning method that uses two GNSS receivers: a reference station (base) and a rover (mobile). A reference station is set up at a point whose coordinates are already accurately known, and the difference between the signal received from satellites and the station’s known position is used to calculate positioning errors. That correction data is sent in real time (for example by radio) to the rover, which applies the corrections to its own received satellite signals to determine high-precision coordinates.

The accuracy achieved by RTK is greatly affected by the distance between the reference station and the rover (the baseline length). If they are close, delays caused by the ionosphere and troposphere are nearly common to both and can be canceled out; as the distance increases, uncorrectable errors grow. Traditionally, this meant placing a reference station within a few kilometers of the work area and transmitting correction information via low-power radio, which was the common operation. With proper operation, horizontal accuracy on the order of 1–2 cm can be obtained, enabling far more precise positioning than conventional GPS, which had meter-level errors.

The constraint of RTK that required installing a reference station on site each time was solved by network RTK. This system utilizes a network of many reference stations (electronic reference points) pre-deployed across the country and generates correction data as if a virtual reference station were located near the user. In a representative method called VRS (Virtual Reference Station), when the user device (rover) sends its approximate position to a server, the server integrates and analyzes observation data from multiple surrounding reference stations and creates correction information by assuming a “virtual reference station” near the user.

The generated virtual reference station correction data is delivered to the local rover via the Internet (mainly using a method called Ntrip). Because the rover can perform RTK positioning under conditions as if a reference station were “right next to it,” high-precision positioning over a much wider area becomes far easier than before.

With the advent of network RTK, users no longer need to provide their own reference station on site; surveying can be completed with a single receiver (rover). Time and effort for preparations are greatly reduced, improving work efficiency. Because the virtual reference station is always set near the measured point, accuracy degradation due to baseline length is almost eliminated, allowing uniform high precision even across wide work sites.

In Japan, the Geospatial Information Authority of Japan has established about 1,300 electronic reference points nationwide and built a system (the GNSS Continuous Observation System) that provides correction information in real time. By using this, it is possible to obtain absolute coordinates in the Japan Geodetic Datum 2011 (the global geodetic system) in real time without placing a reference station on site. Private services that use mobile communication networks for network RTK are also widespread, with major carriers deploying their own networks of thousands of reference points. As long as you are within a communication area, it is now possible to obtain stable centimeter-level positioning anywhere in Japan.

Recently, methods that receive correction information directly from satellites have also emerged, in addition to systems that use ground reference station networks. One example is the centimeter-level augmentation service (CLAS) provided by Japan’s Quasi-Zenith Satellite System “Michibiki”; using a compatible receiver, centimeter-level positioning can be achieved in real time without the Internet. Receiving augmentation signals from satellites is free to use, which is another advantage. Because high-precision positioning can be achieved even in mountainous areas outside mobile coverage, use of these methods is expected to expand further.

As shown, the spread of network RTK has brought great benefits to surveying sites. Next, let’s look at the specific advantages.

Benefits Network RTK Brings to the Field

Now that we understand how network RTK works, let’s see what actual benefits it brings to field surveying operations. Compared with conventional methods, introducing network RTK offers the following advantages:

• No need to set up a reference station: There is no need to install your own reference equipment on site, reducing the burden of transporting equipment. Costs of procuring multiple expensive base stations are also reduced, and work can be completed with a single receiver.

• Greatly reduced preparation time: Since there is no need to set up a base station or establish control points, positioning can begin immediately on site. Pre-tasks such as traverse surveys or establishing reference points are greatly reduced, allowing limited work time to be used more effectively.

• Stable high-precision positioning: Centimeter-level accuracy can be obtained uniformly even for wide-ranging sites. There is no worry about accuracy degradation due to distance from a base station, making it easier to manage positioning quality.

• Work possible with fewer personnel: Since positioning can be performed with just one receiver and a communication environment, traditional roles such as observation assistants or base station managers are unnecessary. More tasks can be handled by a single person, helping address labor shortages.

• Improved consistency with design data: Network RTK can directly obtain absolute coordinates based on global geodetic systems, reducing discrepancies with the coordinate systems used in design drawings. Measured points can be plotted directly on drawings, lowering the risk of errors from coordinate transformations or conversions to local coordinate systems.

• Compatibility with ICT technologies: High-precision position data from network RTK can integrate with advanced ICT technologies such as drone photogrammetry, machine guidance for construction equipment, and AR-based site visualization. Combined with real-time sharing of survey data, it becomes a powerful foundation for driving on-site digital transformation (DX).

Survey Data Sharing Expanded by Cloud Integration

Once network RTK dramatically improves field positioning accuracy and efficiency, the next key is how to utilize and share that survey data. This is where cloud integration proves powerful. By connecting surveying equipment to the Internet and storing and sharing acquired data in the cloud, information flow between the field and the office (designers) becomes far smoother.

Traditionally, surveyors would bring data collected on site back to the office on USB sticks or in handwritten notebooks, then organize and hand it over to designers. This introduced time lags before survey results were reflected in designs and created risks of transcription errors. Introducing cloud-based data sharing eliminates such physical handoffs and enables instant, accurate sharing of survey data.

Main benefits of cloud integration:

• Immediate information sharing between field and office: Coordinates of measured points, photos, and other data can be uploaded to the cloud on site, and office-based designers can check the latest data instantly. Waiting time for survey results is reduced, and designs or reviews can be updated the same day.

• Prevention of transcription errors: Because data is shared automatically without passing through handwriting or Excel input, human transcription errors are eliminated. Everyone can share a single, up-to-date version of the data, avoiding confusion over which file is the latest.

• Simultaneous use by multiple stakeholders: Cloud-stored survey data is accessible not only to field personnel but also to designers and project managers. When everyone sees the same information during discussions and decision-making, communication loss is reduced and team productivity improves.

• Faster feedback: With a two-way connection between field and design via the cloud, designers can easily request additional measurements or instruction changes during surveying. If unexpected issues arise on site, the situation can be shared immediately with photos and notes, enabling rapid consideration of design changes.

• Secure data storage: If data is stored in the cloud, it is not lost in case a device is lost or damaged. Historical survey records can be centrally managed, making it easy to review “when and where what was measured” later.

Thus, cloud integration greatly expands how survey data can be used and contributes to optimizing the entire workflow.

A New Workflow Connecting Field and Design

Combining network RTK and the cloud enables a new workflow in which field and design are seamlessly connected. Here is one example laid out step by step.

• Field Survey: Surveyors use GNSS receivers that support network RTK to measure points on site. There is no need to set up reference points or wait for post-processing as before; centimeter-accurate coordinates can be obtained on the spot.

• Send Data to the Cloud: Measured positional data and accompanying information such as comments are uploaded to the cloud immediately from the field. With one button, data is saved on the server and automatically shared with stakeholders.

• Data Review in the Office: Designers in the office check the latest cloud-uploaded data on their computers. Measured points are plotted on maps, and photos (if any) are linked to their positions, allowing real-time understanding of site conditions.

• Feedback from Design: As needed, designers can request additional measurement points or changes to the design via the cloud. Instructions can be issued through the shared cloud data without relying on phone or email, making the process efficient.

• Field Response and Additional Measurement: The surveyor carries out additional measurements or layout work based on the design immediately on site. New measurement results are likewise shared to the cloud, enabling designers to make instant decisions while viewing the data.

• Integration of Deliverables: Ultimately, all survey data is aggregated in the cloud. By the time field staff return to the office, work such as updating design drawings or creating as-built diagrams can already be underway, eliminating wait times for data handoffs.

By using network RTK and the cloud, the data exchange between field and design that used to take days becomes nearly real time, drastically reducing turnaround time and rework. Because high-precision survey data collected on site can be reflected in designs immediately, discrepancies in later stages are minimized, contributing to higher-quality deliverables.

Summary

Network RTK combined with cloud data sharing is transforming how surveying is done. Accurate positioning information collected on site is delivered instantly to designers, and design feedback can be received on the spot. Field and design, which used to operate separately, are now synchronized in real time, reducing needless waiting and rework and improving project speed and quality.

One solution gaining attention for easily realizing such advanced surveying workflows is LRTK. By combining a small high-precision GNSS receiver with a smartphone, LRTK enables people without specialized training to perform centimeter-accurate surveying solo. It also offers diverse features such as photo capture, point cloud scanning, and AR surveying, allowing comprehensive digital capture of site conditions with a single device. Positioning data and site photos are uploaded on the spot to the cloud (LRTK Cloud) and shared instantly with office teams. LRTK is a practical tool that embodies the “cloud-integrated survey data sharing” discussed in this article. Take note of how LRTK can maximize the benefits of network RTK and cloud use to support smarter surveying. The use of network RTK to connect field and design in real time will increasingly become a trump card for improving operations across many sites.

FAQ

Q: What is network RTK? A: Network RTK is a technology that performs high-precision positioning by receiving correction information provided by multiple reference stations over the Internet. Unlike traditional RTK, there is no need to set up your own base station on site; correction data enabling centimeter-level accuracy is obtained from nearby reference station networks via a communication link.

Q: What is required to use network RTK? A: An RTK-capable GNSS receiver and a communication environment to receive correction information are required. Specifically, a receiver that can connect via a mobile communication network and a subscription to a correction data distribution service (or use of a public augmentation signal) are needed. In Japan, options include paid correction services over mobile networks or using the quasi-zenith satellite Michibiki’s centimeter-level augmentation service (CLAS). In any case, with compatible equipment and communication, real-time high-precision positioning on site is possible.

Q: What are the benefits of sharing survey data in the cloud? A: Using the cloud allows survey data from the field to be shared instantly with the office, greatly reducing time loss. You no longer need to carry data back on USB sticks, preventing transcription errors, and multiple people can access the latest data simultaneously, facilitating collaboration. Data stored in the cloud is also safe from device failure, and past survey records can be managed centrally.

Q: Can centimeter-level surveying really be done with a smartphone? A: Yes, if you connect a dedicated high-precision GNSS receiver to a smartphone or tablet. Smartphones alone do not offer high positioning accuracy, but combining them with a high-precision antenna/receiver and using network RTK corrections can achieve accuracy comparable to dedicated surveying equipment. For example, LRTK uses smartphone-integrated RTK receivers to enable anyone to achieve centimeter-class positioning easily.

Q: Can non-specialist users operate these systems? A: Yes. Recent network RTK–compatible devices and apps are designed to be user-friendly, and many allow intuitive surveying operations. Tools like LRTK that enable one-touch positioning and cloud sharing let users without specialized knowledge handle field surveying. This helps advance on-site digital transformation (DX) without heavy training costs.

Q: How accurate is network RTK positioning? A: When used appropriately, horizontal accuracy is typically around ±1–2 cm and vertical errors are on the order of a few centimeters. This is vastly more accurate than standalone positioning (meter-level errors). However, accuracy can degrade in environments with obstructions or poor signal conditions, and stability can be affected by weather or satellite geometry. For critical surveys, it is advisable to allow margins and perform multiple checks. Even so, network RTK provides dramatically higher accuracy than traditional methods and is a reliable solution for most surveying tasks.