Streamlining Surveying Work with Network RTK: Completing Tasks Alone That Once Required Two People

As labor shortages and demands for greater efficiency press on surveying sites, the recently introduced network RTK technology is overturning long-standing assumptions. By leveraging the latest GNSS positioning technologies, surveying work that once required a pair of workers can increasingly be completed by a single person. This article reviews the challenges of traditional two-person surveying, explains how network RTK works and how it differs from standalone positioning, and outlines concrete procedures and key points that enable solo surveying. It also addresses precautions for maintaining high accuracy and safety, and discusses how digitization improves recording and sharing efficiency. Finally, it introduces recent trends in smartphone-based RTK surveying (LRTK) and considers prospects for further labor reduction in the future.

Traditional two-person surveying and its challenges

On civil engineering sites, surveying has until now been performed as two-person teams as a matter of course. Typical examples include the following tasks.

• Boundary surveying: One person operates the surveying instrument (such as a total station) while the other stands at a distant point holding a prism or staff to measure boundary points. Because two people must align the position and equipment in this way, communication overhead and measurement time increase, reducing operational efficiency.

• As-built measurement: Even for measurements to confirm as-built shapes and dimensions, an assistant traditionally holds a staff at each survey point while the surveyor operates the instrument to read heights and coordinates. The need for synchronized action between two people imposes staffing burdens and increases the risk of human error.

• Staking out (layout): When installing stakes or markers according to design drawings, work is usually carried out by a surveyor and an assistant. One person uses the surveying instrument to indicate positions while the other installs stakes in the ground accordingly. This method can lead to miscommunication of signals causing positional errors, as well as time losses due to movement across large sites.

From measuring boundary points to confirming as-built conditions to staking out positions, surveying has historically required teamwork. Securing personnel places a heavy burden on sites with staff shortages, and is not efficient in terms of labor costs and scheduling. In hazardous environments, two-person work itself can even pose safety management risks. So why is surveying that once required two people now possible to complete alone?

What is network RTK? How it differs from standalone positioning

The key technology enabling solo surveying is network RTK, a GNSS surveying method. RTK (Real Time Kinematic) is a GNSS positioning technique that improves real-time position accuracy by relative positioning between a reference station and a rover. With traditional standalone positioning (standalone GPS surveying), satellite signal errors and atmospheric effects commonly produce position errors on the order of several meters (several ft). RTK surveying operates a known-coordinate reference station (base) and the rover simultaneously, and by correcting errors from the differences in their observations, it achieves accuracy on the order of a few centimeters (a few in).

Network RTK advances RTK further. As the name implies, it utilizes a network of multiple reference stations, allowing users to perform surveying by bringing only a rover to the site. For example, by using data from electronic reference points installed nationwide by the Geospatial Information Authority of Japan or from commercial reference station networks via the Internet, there is no need to set up a reference station at the site. The rover’s GNSS receiver transmits positioning data via mobile communications, and server-side comparison and correction using nearby reference station information provide high-accuracy coordinates in real time.

The major difference from standalone positioning is positioning accuracy and stability. Standalone positioning typically provides instantaneous positions with errors of a few meters (a few ft), making it unsuitable for accuracy-critical boundary measurements or as-built management. In contrast, network RTK positioning delivers centimeter-level accuracy (half-inch accuracy) almost uniformly nationwide thanks to the extensive network of reference stations. Even if the nearest reference station is far from the site, network RTK employs techniques such as setting a virtual reference station (VRS) near the measurement point to prevent accuracy degradation. As a result, surveying over wide areas while moving is stable in accuracy, allowing work without concern for distance from a reference station.

Network RTK also enables simplification of equipment. Traditionally, RTK required setting up your own reference station GNSS receiver, but by using correction information via the network, you only need to bring a rover to the site. This directly reduces setup and takedown time and allows surveying to begin soon after arrival. In these ways, network RTK can be considered a next-generation surveying infrastructure that realizes high-accuracy positioning with fewer instruments and personnel.

Workflow for solo surveying enabled by network RTK

With the introduction of network RTK, tasks that were previously divided between two people can now be handled by one. This is because a single person can now combine the roles of positioning and point confirmation. Traditionally one person operated the instrument while the other set the target, but with network RTK the user carrying the rover can instantly know their own high-accuracy position. In other words, by simply standing at the point to be measured while moving, that location becomes the measurement point. Here is an example of concrete solo surveying procedures.

• Equipment preparation and connection: Upon arrival at the site, prepare a network RTK-compatible GNSS receiver (rover). Mount the receiver on a survey pole or monopod and power it on. Then operate the dedicated controller (a surveying terminal, tablet, or smartphone) and confirm communication with the rover receiver. Connect the controller to the Internet and log in to the correction data distribution service you subscribe to (such as Ntrip) to begin receiving correction information.

• Initialization (establishing FIX): Once the GNSS receiver begins receiving satellite signals, perform initialization for high-accuracy positioning. This process waits until the solution reaches the "FIX" state. In an open environment at the site, satellite data and correction information typically stabilize in several tens of seconds to a few minutes, changing the positioning solution from a float to a fixed solution (FIX). Confirm on the controller that FIX has been achieved and verify that position accuracy has reached centimeter-level accuracy (half-inch accuracy).

• Point measurement: When ready, move to the point to be measured holding the pole. For example, when measuring a boundary marker, firmly set the pole tip vertically on the marker and perform a point measurement. Pressing a button on the controller records the current position coordinates. For as-built measurement, move sequentially to each survey point specified in the design and observe in the same way. For staking out (layout) work, the controller compares preset design coordinates with the current position and guides you on the screen; move the pole to the indicated spot and install the stake or marking pin once you are in the correct position. In this way, a single person can carry the pole, move between points, and complete point measurement and staking.

• Data saving and verification: After all required points have been surveyed, save the acquired data on the controller. Measured coordinates can be tagged with date/time and point names, and accumulated as digital surveying deliverables on the device or in the cloud. Display the day’s results on site to check for omissions and, if necessary, perform additional measurements to correct missing or erroneous points. This completes the surveying sequence. Because all these operations can be performed alone, some sites can reorganize movement and measurement steps to allow one person to efficiently accomplish what previously required two people.

This solo surveying workflow using network RTK brings many practical benefits on site. In boundary surveying and as-built measurement, the stress of coordinating procedures with others is eliminated, smoothing work. Even in staking out, instant position confirmation and stake setting by the operator remove wait times for signals and communication errors. Overall, the ability to survey alone not only alleviates staffing shortages but also improves rapid response capability on site.

Balancing accuracy control and work safety

Even when performing surveying work alone, ensuring survey accuracy and safety management is more important than ever. For accuracy control, it is essential to trust network RTK’s high accuracy while still conducting on-site verification. For example, before or during work, intentionally measure known points such as control marks or existing boundary markers whose positions are clear, and validate obtained coordinates to check instrument performance. Continuously monitor on the controller whether the RTK receiver maintains a FIX solution and, if satellite reception deteriorates causing unstable accuracy, decide not to continue work unnecessarily. Also, being a solo operator is a good reason to thoroughly apply basic accuracy-assurance practices, such as checking pole verticality with a bubble level and taking multiple observations at each point and averaging them. Because network RTK correction data depend on a communications line, in mountainous areas or other sites with poor mobile reception, check communications in advance and consider countermeasures such as equipping the rover with radio communication capability or using the Quasi-Zenith Satellite System “Michibiki” augmented signal (CLAS).

Next, ensure safety during work. When working alone on site, there are no nearby colleagues to share awareness of conditions, so careful behavior with safety first is required. Before starting work, sufficiently check hazardous areas and permitted access ranges and, if necessary, notify stakeholders of the work area. During operations, always watch your surroundings; if heavy equipment or vehicles are nearby, actively make your presence known — compensating for the vigilance a partner might otherwise provide. Also, for surveying in hazardous terrain such as fallen trees, steep slopes, high places, or on roads, do not attempt to perform the task alone if it is unsafe; call for assistance as appropriate. Even while using the latest network RTK equipment, always remember that the fundamentals of surveying remain the same and your awareness of safety must not change.

Improved efficiency in recording, sharing, and report output through digitization

Solo surveying with network RTK has brought transformation not only to field procedures but also to how survey data are recorded and used. Traditionally, values were handwritten in field books and then digitized in the office, or transcribed into spreadsheets to prepare deliverables. With the digital technologies used in modern surveying, coordinates obtained on site can be saved and shared electronically on the spot, and the creation of forms and reports can be performed seamlessly. Key efficiency points include the following.

• Automatic recording on electronic devices: Observations made by the GNSS receiver and controller are saved in real time as electronic files. While surveying alone, if you enter point names and attributes on site, you won’t need to decipher paper notes later. This prevents handwriting and transcription errors and contributes to data quality control.

• Sharing via cloud or internal networks: Uploading field data to the cloud via mobile communications or sending them to the office’s shared server enables immediate sharing with remote colleagues or clients. For example, sending boundary survey coordinates to the design team for confirmation on the spot can allow you to receive additional instructions immediately. Centralized data management smooths coordination between field and office and improves overall operational efficiency.

• Faster report and form output: Digital data can be quickly turned into drawings and forms using dedicated software or applications. Reflecting survey results in CAD drawings or 3D models can be completed in a short time if tools automate conversion to the reference coordinate system. Systems that automatically generate as-built photo logs or survey deliverables by linking measured data with photos and comments are becoming more widespread. This greatly reduces the time required to prepare reports, allowing personnel to devote more time to higher-value tasks.

Thus, by centering surveying digitization around network RTK, the entire workflow from on-site measurement to office deliverables is now connected in a single data flow. Combined with the ability to complete surveying alone, this has dramatically improved total operational efficiency including recording, sharing, and reporting.

The advent of smartphone RTK surveying and prospects for further labor reduction

In recent years, advances in network RTK technology have brought about an era in which smartphones can become surveying instruments. A representative example is the new solution called LRTK. LRTK consists of a tiny RTK-GNSS receiver device that attaches to a smartphone or tablet and a dedicated app; attaching a pocket-sized device to a smartphone enables centimeter-level accuracy (half-inch accuracy) positioning comparable to that of traditional expensive surveying instruments. This makes it increasingly feasible for site supervisors and construction managers to perform surveying and layout easily with one smartphone per person.

The strength of smartphone RTK surveying lies in its convenience and versatility. For instance, if a civil site supervisor wants to check a small dimension on site, instead of arranging a surveying crew and remeasuring with a total station, they can measure themselves with a smartphone fitted with an RTK device and obtain immediate results. Systems like LRTK also allow high-precision position information to be combined with photos and notes and recorded to the cloud on the spot. For example, in structural crack inspections, taking a photo with a smartphone can automatically record position coordinates and orientation, blurring the boundary between surveying and record-keeping. If an environment where “anyone can measure anywhere” is established, necessary on-site measurements can be made without relying exclusively on specialized surveyors, enabling further labor reduction and faster operations.

In the future, the spread of smartphone RTK will further advance the “democratization of surveying.” If high-precision positioning is no longer the preserve of specialized technicians but becomes accessible to various on-site personnel, it will directly boost productivity across construction sites. Moreover, as drone automated surveying and integration with machine guidance for construction equipment progress, the scope for unmanned construction—performing surveying and construction without human presence—will expand. Network RTK is the foundational technology supporting these next-generation construction DX initiatives, and the emergence of smartphone RTK (LRTK) is genuinely a trump card for labor and effort reduction. By equipping and empowering each technician with the latest surveying technologies, we can update the long-standing norm of two-person teams and establish efficient, safe surveying practices suited to the times.