RTK Has Become a Standard in Surveying: Organizing Reasons for Its Adoption in the U.S. by Benefits

Table of Contents

• What is RTK?

• Centimeter-level high-precision positioning

• Efficiency gains from real-time measurement

• Enabling one-person surveys and labor savings

• Handling difficult conditions without line-of-sight

• Improved safety

• Data sharing and digital integration

• Cost reduction and return on investment

• Simple surveying with LRTK

• FAQ

In recent years, RTK (Real Time Kinematic) — a high-precision GNSS positioning technology — has been becoming standard in surveying. In particular, in advanced countries such as the United States, RTK surveying has already been widely adopted as a de facto standard. Why has RTK become so widespread? The reason lies in the many benefits RTK brings. For surveyors and construction management engineers, adopting RTK has become an unavoidable trend. Actively embracing advanced technology to improve productivity and result accuracy will become increasingly important. Compared with traditional surveying methods, RTK offers superior characteristics in terms of accuracy, operational efficiency, and cost. This article organizes the main benefits of RTK and explains why they have driven increased adoption in the U.S. At the end of the article, we also introduce a new solution, LRTK, for simple surveying.

What is RTK?

RTK is a technology that uses GNSS (Global Navigation Satellite System) to perform high-precision positioning in real time. It employs a reference station (base station) and a mobile station (rover); the base station sends observed error information as correction data to the rover, correcting satellite positioning errors in real time. As a result, errors that were on the order of several meters with standalone positioning can be reduced to survey-grade accuracy within a few centimeters (half-inch accuracy) for position determination.

The advent of RTK-GNSS surveying has greatly improved efficiency for tasks that had previously been performed with optical total stations or static GNSS surveying (which required post-processing), and its use has expanded worldwide. In the U.S. in particular, RTK is widely used across applications from construction site as-built control and land surveying to autonomous tractors in agriculture, and has become a mainstream surveying method. For example, using RTK to locate underground water/sewer pipes and communication cables can reduce the risk of accidental damage during excavation. In agriculture, autonomous tractors use RTK for precise position control to travel in straight lines and perform seeding and fertilization without overlap or unevenness. In this way, RTK is utilized across many fields, and its usefulness is recognized in many places.

Centimeter-level high-precision positioning

One of RTK’s greatest advantages is its positioning accuracy. Through relative positioning with a base station, RTK can obtain extremely high real-time accuracy within a few centimeters (half-inch accuracy) both horizontally and vertically. This level of accuracy is a dramatic improvement over conventional standalone GPS positioning, which has errors on the order of meters. It not only meets the accuracy required for many surveying tasks (such as boundary measurements and setting out for design/construction) but has reached a level where precision measurements that previously required a total station can be replaced by RTK. For example, small-scale land boundary surveys or building layout positioning can achieve the necessary accuracy with RTK. The ease of achieving such high precision is a major reason surveyors have embraced RTK.

Efficiency gains from real-time measurement

As the name “Real Time” suggests, a major benefit of RTK is that high-precision position information is obtained immediately on site. Coordinates of points acquired in the field can be confirmed on-site immediately, eliminating the need to return to the office for calculations or post-processing. For example, static GNSS surveying traditionally required post-observation analysis against reference point data, but with RTK results are available the moment a measurement is taken, allowing immediate progression to the next point.

Compared with total station surveys, RTK also reduces the need for equipment re-setup (for line-of-sight), enabling larger areas to be surveyed in a shorter time. Even on sites spanning several hectares, a rover can be carried while continuously acquiring survey points without repeating traverse surveys, significantly shortening work time. Vast survey areas that used to take several days can sometimes be completed in half a day to one day using RTK. For instance, a site of about 100 acres (40 hectares) that required three days with a total station was reported to be completed in less than one day with RTK.

Furthermore, because positioning results are obtained in real time, surveys can be advanced while checking and verifying data on site. Incorrect points or missing data can be identified immediately and re-measured as needed. This prevents unnecessary rework such as returning to the site later due to data deficiencies.

Enabling one-person surveys and labor savings

The ability to complete surveying tasks with a single person thanks to RTK is another important point. Traditional total station surveys required a two-person team: an operator for the instrument and an assistant holding the prism. With RTK, once a base station is set up, a single surveyor with a rover can sequentially measure points. Moreover, by using public reference station networks (such as CORS) or internet-based correction services, there is often no need to set up a private base station at all, allowing one person to perform surveys with only a rover.

This capability for solo work is a significant benefit in the surveying and construction industries, which face labor shortages and an aging workforce. Completing tasks with one person reduces labor costs and simplifies personnel coordination. RTK has been particularly welcomed in the U.S., where many sites are large, because it allows efficient work with small crews. As a result, limited personnel can complete many surveys in a short time, directly improving productivity.

Handling difficult conditions without line-of-sight

Another advantage of RTK surveying is that optical line-of-sight between instruments is not required. Total stations require a direct line-of-sight between the instrument and the prism, so measurements are difficult in areas blocked by trees or buildings. RTK can position as long as GNSS satellites in the sky can be received, making surveying possible in forests and narrow urban spaces. This eliminates the need to clear obstacles to secure visibility or repeatedly re-set equipment.

For example, RTK can smoothly survey in situations such as:

• Boundary surveys within dense forests (no need to secure line-of-sight)

• Urban areas with high-rise buildings (positioning possible in building shadows)

• Vast terrain with large relief (one base station can cover a wide area)

In this way, RTK demonstrates its power in places that were previously difficult to measure and has greatly expanded the applicable range of surveying. In regions with diverse terrain and environments like the U.S., this flexibility of RTK is highly valued.

Improved safety

The spread of RTK has also contributed to improved safety in surveying work because it reduces the time spent measuring in hazardous locations. For example, point observations on busy roadways can be completed quickly with RTK. Compared with standing for long periods holding a prism on the road for a total station, rapid measurement and retreat reduce safety risks.

RTK combined with drones (UAVs) also enables surveying in areas where people cannot enter. Using RTK-capable drones to acquire topographic data from the air removes the need for surveyors to go to dangerous slopes or cliff edges. Aerial photogrammetry with RTK-capable drones can greatly reduce the need to place ground control points (GCPs) that were previously necessary, reducing survey preparation work. Surveying at heights or on unstable ground can be carried out more safely and efficiently than direct human measurement.

Thus, RTK technology contributes not only to accuracy and efficiency but also to ensuring worker safety.

Data sharing and digital integration

Because RTK survey data are all obtained electronically, digital utilization is easy. Point coordinates are recorded on tablets or PCs in the field and can be reflected in CAD drawings or GIS maps immediately.

Moreover, data can be shared in real time between the field and the office via mobile networks or the internet. For example, a surveyor can send observed point information from the field to the office via the cloud, allowing colleagues located remotely to check and process the data immediately.

This digital integration further improves efficiency, reduces mistakes, and facilitates smooth information sharing within teams. Reducing analog records and manual input also helps suppress human error. In the U.S., where IT infrastructure is well developed, cloud-based surveying workflows have become common, enabling flexible operations such as immediately sharing field data for design. These digital surveying workflows centered on RTK also contribute to promoting DX (digital transformation) in the construction and surveying industries.

Cost reduction and return on investment

All of the above benefits ultimately lead to significant cost reduction. Using RTK allows the same surveying work to be completed in less time and with fewer personnel, reducing labor costs and daily operational expenses. For example, work that previously took two people three days but can be done by one person in one day will greatly reduce labor and equipment operation costs.

Real-time positioning also reduces errors, suppressing rework and additional investigations, which further contributes to cost reduction.

Furthermore, prices for RTK equipment have been decreasing in recent years. High-precision GNSS receivers, which were once expensive, have become more accessible due to technological progress and market expansion. In the U.S., state CORS networks and private correction services are well developed, providing environments where RTK can be used affordably without installing an expensive private base station. For example, many states offer government-run real-time GNSS reference station services for free or at low cost, making RTK adoption easier for small surveying firms. Nationally deployed CORS (Continuously Operating Reference Stations) have also strongly supported RTK diffusion. In Japan, too, the environment surrounding RTK has steadily improved through the Geospatial Information Authority’s electronic reference station network (GEONET) and the launch of the QZSS “Michibiki” centimeter-level augmentation service (CLAS). The expansion of RTK demand beyond surveying — such as autonomous tractors in agriculture and drone surveying — has also driven mass production and reduced equipment costs. These infrastructure improvements have further promoted adoption.

Overall, productivity gains and expense reductions from RTK make its cost-effectiveness very high, bringing substantial benefits to survey business management.

Simple surveying with LRTK

Although RTK’s advantages are significant, RTK surveying traditionally required dedicated, expensive equipment and specialized knowledge, creating a barrier to adoption in some cases. Recently, however, a new solution called LRTK has emerged that greatly lowers these barriers.

LRTK consists of a small RTK-GNSS receiver that attaches to a smartphone and a dedicated app, enabling anyone to easily perform centimeter-level surveying (half-inch accuracy). Simply attaching a pocket-sized receiver weighing approximately 125 g to a smartphone allows even those with little equipment operation experience to perform high-precision position measurements and record points. The price is very affordable compared with conventional surveying equipment, and products are designed as field tools that each worker can carry. Because they can be taken out and used whenever needed, work that previously had to wait for surveying specialists can be carried out promptly.

With LRTK, point coordinate measurements, stakeout positions, and simple topographic point cloud measurements can all be done with just a smartphone. Collected data can be uploaded to the cloud on site and shared with the office. Especially in mountain areas or disaster sites where internet connectivity is unavailable, LRTK’s built-in high-precision GNSS functionality can provide stable positioning (and supports Japan’s QZSS Michibiki centimeter-level augmentation service (CLAS)). LRTK was also used in field surveys after the 2023 earthquake disaster, where its function to automatically record accurate position and orientation information on photos taken with a smartphone aided efficient damage assessment. In this way, LRTK is expected to make RTK surveying more accessible and simple, significantly contributing to improved field productivity. These advanced technologies also align well with i-Construction (the Ministry of Land, Infrastructure, Transport and Tourism’s initiative to reform construction production processes using ICT), so further penetration of RTK into Japanese sites is expected. LRTK is a promising option for those considering RTK adoption.

FAQ

Q: What is RTK? A: A technology that corrects GNSS positioning errors in real time to achieve centimeter-level high-precision positioning (half-inch accuracy). It uses a base station and a rover; the base station sends observed error information by radio or other means to precisely calculate the rover’s position. It is widely used in surveying and construction fields.

Q: What is needed for RTK surveying? A: Basically, an RTK-capable GNSS receiver (rover) and a base station (or a network service that provides correction information) are required (a mobile communication environment is also needed when using an RTK network). The base station can be installed privately or you can use reference station services provided by government or private entities (internet-based RTK networks). Radios or mobile lines to connect the rover and base station are also prepared. Recently, easy-to-use products combining a smartphone and a small receiver (e.g., LRTK) have also appeared.

Q: Can RTK completely replace all conventional surveying instruments? A: RTK can streamline many surveying tasks, but there are situations where traditional instruments remain effective. For example, RTK cannot be used in environments where GNSS signals do not reach, such as inside buildings or tunnels; total stations or leveling instruments are required. Also, for ultra-high-precision measurements requiring sub-millimeter accuracy, optical distance measurement or precise leveling may be more suitable. Therefore, in practice it is ideal to use RTK and conventional methods according to the application and combine them as needed. RTK is also affected by satellite signal reception conditions and atmospheric conditions, so for critical situations it is desirable to cross-check with multiple surveying methods.

Q: Why has RTK spread in the United States? A: As discussed in the article, RTK’s advantages in terms of high accuracy, efficiency, and cost are major factors. In a large country like the U.S., the efficiency of being able to survey wide areas in a short time is particularly valued. Furthermore, many states have established RTK reference station networks, making RTK environments available at relatively low cost, which has driven adoption. High labor costs in the U.S. also make investment in labor-saving technologies economically attractive. Combined with a population that is receptive to technological innovation, RTK has become a commonplace presence on U.S. survey sites.

Q: What is LRTK? A: A new RTK surveying system used in combination with a smartphone. A small RTK-GNSS receiver is attached to a smartphone and operated via a dedicated app. It enables anyone to easily achieve centimeter-level positioning (half-inch accuracy) and includes diverse functions such as point measurement, stakeout, point cloud measurement, and AR-based position display. It significantly improves portability and ease of use compared with traditional dedicated RTK equipment. It is lower-cost than conventional dedicated equipment and is designed so field workers can each carry one device.

Q: How do I introduce RTK? A: Basically, procure an RTK-capable high-precision GNSS receiver (rover), a base station, and dedicated positioning software, then set them up and use them on site. Introduction involves purchasing or renting equipment and gaining operational proficiency, but solutions like LRTK combining a smartphone and a small receiver are now available for quick starts. Consider RTK adoption in a way that fits your company’s needs. A practical approach is to pilot RTK on small sites first to accumulate in-house operational know-how.