Table of Contents

• Introduction

• What is RTK (single base station)?

• What is network RTK (VRS)?

• Differences between single-base RTK and network RTK

• Key points for successful one-person surveying

• Introduction to simple surveying with LRTK

• FAQ

Introduction

In recent years, on surveying sites there has been an increase in cases where tasks that previously required two or more people are completed by a single person—so-called one-person surveying. In particular, advances in RTK GNSS positioning, a high-accuracy positioning technology, have made it possible for one person to measure positions efficiently and accurately. For example, when performing terrestrial surveys with a total station in the past, a pair consisting of a surveyor and a prism staff was required, but with RTK-GNSS a single person can rapidly observe many points. To answer the question “Can one person handle surveying with RTK?” this article explains the mechanisms and differences of RTK and network RTK (VRS) and explores practical operational lines and safety points for one-person surveying.

What is RTK (single base station)?

First, let’s briefly outline RTK (Real Time Kinematic) positioning. RTK is a method that uses one base station and one rover, exchanging satellite observation data observed simultaneously by both GNSS receivers in real time to correct positioning errors. The base station is installed at a point whose coordinates are known accurately in advance; it calculates the error from the difference between the satellite signals it receives and its known accurate position. It then sequentially transmits that correction data to the rover via wireless communication or other means. The rover combines the correction data with its own GNSS observations and computes in real time to cancel positioning errors (such as delays caused by the path of satellite signals), enabling centimeter-level high-accuracy positioning of its own location.

RTK positioning is characterized by its ability to dramatically improve accuracy by relative positioning with a base station, where standalone GNSS positioning with a single receiver would typically produce errors of several meters. If operated properly, horizontal accuracy on the order of 1-2 cm (0.4-0.8 in) can be obtained, making it invaluable on sites such as civil engineering works and control point establishment where even a few centimeters of deviation cannot be tolerated.

However, RTK accuracy is greatly influenced by the distance (baseline length) between the base station and the rover. The farther the distance from the base station, the less completely atmospheric effects and other errors can be cancelled, and positioning accuracy gradually degrades. Therefore, in typical RTK operations the base station is set up near the work area (ideally within a few km) and transmits correction information via UHF radio or similar. Conversely, the need to install a base station on site is also a weakness of traditional RTK.

What is network RTK (VRS)?

Network RTK is a method that addresses this. It uses a wide-area network of multiple base stations to provide correction data as if “a base station existed near the user.” In the representative VRS (Virtual Reference Station) method, the user (rover) sends an approximate current position to a server via communication, and the server integrates and analyzes data from multiple surrounding base stations. The server then assumes a virtual base station near the user and generates the satellite signal data that would have been received at that location. By delivering the correction information from this virtual base station to the rover over the network, the rover can perform RTK positioning as if a base station were located immediately adjacent. Besides VRS, there are other variations such as FKP, which corrects regional errors from multiple base station data, but the basic idea is the same: use multiple base stations to improve accuracy across a wide area.

The advantage of network RTK (VRS) is that you do not need to set up your own base station on site, so surveying can be conducted with a single receiver (the rover), greatly simplifying preparation before starting work. Because a virtual reference is always generated near the user, accuracy degradation due to distance from a base station is almost negligible, allowing continuous centimeter-level accuracy over large areas for mobile surveying.

In Japan, the Geospatial Information Authority provides real-time services based on a nationwide network of about 1,300 continuously operating GNSS reference stations. Paid correction services from private companies have also become widespread, making stable high-precision positioning possible nationwide as long as a communication environment is available. For example, in precision agriculture over vast farmland, and long-distance infrastructure surveys such as roads and railways—which previously required relocating base stations by area—network RTK enables continuous positioning over wide areas with a single rover. It is also efficient for applications requiring unified coordinates over wide areas, such as aerial photogrammetry with drones and autonomous vehicle navigation.

On the other hand, using network RTK requires the rover to have an internet connection via a communication modem or smartphone (receiving data via Ntrip). In mountainous areas or locations without coverage, correction data may not be receivable, so in such environments traditional RTK with an on-site base station may be advantageous.

Differences between single-base RTK and network RTK

Both RTK (single base station) and network RTK (VRS) are high-accuracy techniques that can achieve real-time centimeter-level positioning, but their operational forms differ greatly. Let’s summarize the advantages and disadvantages of each.

● Advantages of single-base RTK

• By operating your own base station, you can continue high-precision positioning without relying on external services. Once you have installed base station equipment you can operate independently while keeping running costs low.

• If radio reaches, it can be used even outside cellular coverage. In mountainous areas or remote islands without mobile communication, surveying can be carried out if corrections can be transmitted by radio.

• You can survey using a local coordinate system based on your base station, which is convenient when you want to work in a site-local coordinate system (e.g., if the base station position is set to an arbitrary point).

● Disadvantages of single-base RTK

• Initial costs for a base station GNSS receiver, radios, tripods, batteries, etc., are high, and transporting and setting up equipment requires effort. Because the base station must be set up on site, time is required before starting work.

• Accuracy degrades significantly if you are too far from the base station. At distances of several tens of km or more, corrections cannot keep up and the method becomes practically unusable. Therefore, when surveying a wide area you must divide the area and repeatedly relocate the base station.

• Maintenance and management of the base station are required. Site securing, theft prevention, battery replacement, and obtaining known coordinates for the observation point (or installing on a known point) involve operational expertise and management costs.

● Advantages of network RTK

• No need to provide your own base stations; you can start with just a rover. As on-site setup is unnecessary, preparation time is greatly reduced.

• Stable accuracy can be maintained over wide areas. Because a virtual reference is always generated nearby, accuracy degradation is small even tens of kilometers away, making it suitable for continuous surveying over large areas.

• Efficient for projects with many measurement points or a lot of movement. There is no need to relocate base stations by area, making it suitable for one person to move around and measure many locations.

● Disadvantages of network RTK

• Receiving correction information via the Internet is essential, so you depend on a communication environment. In sites without cellular signal you cannot use the service, and in that case a traditional on-site base station is required.

• Ongoing costs are incurred. Network RTK service fees and communication costs arise, and total costs increase with longer or wider usage.

• Some services fix the reference coordinate system to a geodetic datum (in Japan, JGD2011), so working in a local coordinate system may require coordinate transformations on site.

Considering the above, traditional RTK is suitable when surveying is repeatedly performed within a limited area or where no communication is available. Conversely, network RTK is powerful when surveying over wide areas, when there is a lot of movement, or when one person needs to measure many points efficiently. Network services are becoming mainstream due to cost and convenience, but it is important to choose the appropriate method according to site conditions.

From the perspective of one-person surveying, network RTK is a method that more easily enables truly solo work because you do not have to handle a base station on site. Conversely, when attempting one-person work with single-base RTK, you must consider the effort of setting up and dismantling the base station yourself and the risk of leaving the base equipment unattended during operations.

Key points for successful one-person surveying

With the advancement of RTK technology, surveys that used to require two people with a total station can increasingly be performed by one person using GNSS. However, to carry out one-person surveying safely and reliably, several points must be observed.

• Prepping and planning: Because you are working alone, preparation and planning are crucial. Understand travel routes and measurement points and make a plan that allows efficient movement. Also be sure to check equipment battery status, prepare spare batteries, and confirm the communication environment.

• Ensuring safety: Surveying in hazardous locations or on sites with heavy machinery increases risk when working alone because you cannot continuously watch your surroundings. Take safety measures as necessary, such as cordoning off the work area or having a third party watch over you. Avoid working at heights or at night if possible; if you must work alone in such conditions, ensure full safety equipment such as helmets and lights.

• Securing communications: When working alone you may not have anyone nearby to call for help in case of trouble. Make sure you can contact others via mobile phone or radio. Consider regular status reports for safety management.

• Ease of handling equipment: Since you must carry and operate equipment alone, a lightweight and simple setup reduces burden. Recently, small GNSS receivers and smartphone-connected apps have appeared, providing solutions that one person can intuitively handle.

• Skills training: Because you will handle equipment alone, receive plenty of training in advance. Going to a site without being proficient with RTK receivers and software may leave you unable to troubleshoot problems by yourself. Practice procedures in a safe environment and understand device behavior before the real operation.

Introduction to simple surveying with LRTK

As described above, the spread of network RTK and the miniaturization of devices have made one-person surveying a practical choice. A representative example is the LRTK solution provided by our company. LRTK was developed under the concept of “a pocket-sized RTK surveying device anyone can use,” and by combining a dedicated device with a smartphone it enables centimeter-level positioning easily. The compact terminal, weighing about 125 g and about 13 mm (0.51 in) thick, integrates the GNSS antenna, receiver, battery, and communication module. Attaching it to a smartphone and launching the app starts high-precision positioning.

Compared to conventional RTK equipment, no cable connections or complicated settings are required, and it is designed to be intuitive even for those without surveying expertise. It links with smartphones via Bluetooth or Wi‑Fi and automates receiving corrections and uploading positioning data to the cloud, dramatically improving field work efficiency. The higher-end model, LRTK Pro2, supports the centimeter-class augmentation service (CLAS) provided by Japan’s Quasi-Zenith Satellite System (Michibiki), enabling high-precision positioning even in mountainous areas outside cellular coverage using only satellite augmentation signals. The LRTK series is also designed to be compatible with the Ministry of Land, Infrastructure, Transport and Tourism’s i-Construction standards, and is attracting attention as a solution that supports DX (digital transformation) in the construction industry from the field.

By using LRTK, you can realize the convenience of network RTK and the latest GNSS technology in the palm of your hand, bringing us to an era where “RTK surveying can be safely performed by anyone alone.” Even on sites requiring high precision, LRTK can let one person accomplish tasks that previously required multiple personnel quickly. Consider LRTK for simple surveying as a tool to expand the possibilities of one-person surveying.

FAQ

Q1. Is there a difference in accuracy between RTK and network RTK (VRS)? A1. The basic positioning accuracy itself can be on the order of a few centimeters for both when operated properly. However, conventional RTK worsens as the distance to the base station increases, whereas network RTK maintains a virtual reference near the user and thus has the advantage of maintaining uniform high accuracy over wide areas.

Q2. What is required to use network RTK? A2. To use network RTK you need a compatible GNSS receiver (rover) and a communication environment. The receiver must connect to the Internet via a mobile router or smartphone to log in to a correction information distribution service (Ntrip server) and receive data. In many cases, a paid correction service subscription is required. Check the mobile coverage in your operating area in advance and complete any necessary communication contracts and service registrations.

Q3. What should I be careful about when performing RTK surveying alone? A3. When performing surveying alone, pay attention to both safety and efficiency. From a safety perspective, avoid hazardous locations as much as possible, and if necessary consider safety equipment or third-party support. For efficiency, identify measurement point locations in advance and optimize the visiting order, and consolidate equipment into a compact, easy-to-carry setup. Also ensure you have a way to communicate externally at all times and be prepared for emergencies. To prevent overlooking measurement data or recording errors, frequently check measurement results during work and make backups as needed.

Q4. What are the advantages of setting up your own base station? A4. If you set up your own base station, you can perform stable high-precision positioning without relying on external services. After the initial investment the running costs can be kept low, and you can position via radio communication even in areas without cellular coverage. Placing your base station on a known point gives you immediate absolute coordinates in the geodetic datum, and placing it on an arbitrary point makes working in a local coordinate system easy, offering operational flexibility.

Q5. What is LRTK? A5. LRTK is a new RTK positioning solution with excellent portability and simplicity. A small device that fits in your pocket paired with a smartphone app enables anyone to perform centimeter-accuracy surveying easily. Compared to conventional equipment it greatly simplifies preparation and operation and strongly supports solo surveying operations. It is designed to be used without specialist knowledge, significantly lowering the barrier to RTK surveying. Higher-end models also enable high-precision positioning using satellite augmentation signals even in mountainous areas outside cellular coverage, ensuring stable positioning in any environment.

Q6. Which should I choose, RTK or network RTK? A6. The choice depends on the site environment and application. For example, if the survey area is limited and extremely high precision is always required, operating your own base station with the RTK method may be the most stable option. Conversely, if you will be surveying while moving over a wide area or if the region has reliable communication infrastructure, network RTK is easier and more efficient. Consider initial investment and running costs as well. It is advisable to perform a trial operation (demo) at the actual site before introduction to verify communication conditions and accuracy. Don’t decide based solely on theoretical comparison—field verification lets you confirm the effects of surrounding terrain and communication conditions and helps prevent problems after implementation.