Can RTK Surveying Be Done by One Person? The Practical Line and Safe Operation of One-Man Surveying

Table of Contents

• Introduction

• What is RTK (Single Reference Station)?

• What is Network RTK (VRS)?

• Differences Between Single RTK and Network RTK

• Key Points for Successful One-Man 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 traditionally required two or more people are completed by a single operator — so-called one-man surveying. In particular, advances in RTK GNSS, a high-precision positioning technology, have made it possible for one person to measure positions efficiently and accurately. For example, in the past a total station survey required a two-person team consisting of a surveyor and a prism pole operator, but with RTK-GNSS a single person can quickly observe many control points. To answer the question, "Can RTK surveying be carried out by one person?", this article explains how RTK and network RTK (VRS) work and their differences, and explores realistic operational lines and safety points for one-man surveying.

What is RTK (Single Reference Station)?

First, let’s briefly review RTK (Real Time Kinematic) positioning. RTK uses one reference station (also called a base station) and one rover (mobile station). The two GNSS receivers simultaneously observe satellite data, and by exchanging that data in real time the method corrects positioning errors. The reference station is set up at a point whose precise coordinates are known in advance; it computes errors from the difference between the satellite signals it receives and the known precise position. The station then sequentially sends that correction data to the rover via radio communication or other means. The rover combines the correction data with its own GNSS observations and computes its position in real time, canceling out positioning errors (such as signal path delay errors) to yield centimeter-level accuracy (half-inch accuracy).

RTK positioning is characterized by dramatically higher accuracy compared with standalone positioning (a single GNSS receiver), which can have errors on the order of several meters. Properly operated, horizontal accuracy of about 1–2 cm (0.4–0.8 in) can be obtained, making RTK invaluable for civil engineering construction and control point establishment where even a few centimeters of discrepancy are unacceptable.

However, RTK accuracy is greatly affected by the baseline length — the distance between the reference station and the rover. As the rover moves farther from the reference station, atmospheric effects make it harder to fully cancel errors, and positioning accuracy gradually degrades. For this reason, conventional RTK operations typically place the reference station near the work area (ideally within a few km) and transmit correction information via UHF radio or the like. Conversely, the need to install a local reference station has been a weakness of traditional RTK.

What is Network RTK (VRS)?

Network RTK was developed to address that limitation. This method uses a wide-area network of multiple reference stations and provides corrections as if a reference station were located near the user. The representative VRS (Virtual Reference Station) method works by the user (the rover) sending its approximate current position to a server via communication; the server integrates and analyzes data from surrounding multiple reference stations. The server then assumes a virtual reference station near the user and generates the satellite signal data that would have been received at that virtual location. By delivering that virtual reference station correction information to the rover over the network, the rover can perform RTK positioning as if an actual reference station were right next to it. In addition to the VRS approach, there are variations such as the FKP method that correct regional errors from multiple reference stations, but the basic idea is the same: using multiple bases to improve accuracy over a wide area.

The advantage of network RTK (VRS) is that you do not need to install your own reference station on site, allowing surveying with a single receiver (the rover) and greatly simplifying preparation before starting work. Because a virtual reference station is always set near the user, accuracy degradation due to distance from a base station becomes almost negligible. This enables mobile surveying over wide areas while maintaining uniform centimeter-level accuracy (half-inch accuracy).

In Japan, the Geospatial Information Authority operates a nationwide network of about 1,300 Continuously Operating Reference Stations (CORS), and real-time services using this network are available. Commercial paid correction services are also widespread, so with an adequate communication environment high-precision positioning is possible virtually anywhere in the country. For example, in precision agriculture on vast farmland or long-distance infrastructure surveys for roads and railways, where previously base stations needed to be reinstalled by area, network RTK allows continuous positioning across wide areas with a single rover. It is also effective for applications requiring unified coordinates over wide areas, such as drone photogrammetry and autonomous vehicle navigation.

On the other hand, using network RTK requires the rover to have an internet connection (receiving data via Ntrip through a modem or smartphone). In mountainous or communication-dead zones you may be unable to receive correction data, so in such environments traditional RTK with an on-site reference station may be more advantageous.

Differences Between Single RTK and Network RTK

RTK (single reference station) and network RTK (VRS) both realize real-time centimeter-level positioning (half-inch accuracy), but their operational forms differ significantly. Let’s summarize theメリット and デメリット of each.

● Advantages of Single Reference Station RTK

• Operating your own reference station means you can continue high-precision positioning without relying on external services. Once you invest in base station equipment, you can run it in-house with lower running costs.

• It can be used even outside cellular coverage as long as radio communication is possible. In mountainous or remote island areas without mobile coverage, surveying is possible if you can communicate between the base and rover via radio.

• Since you can survey based on your own reference station coordinates, it’s convenient when you want to work in a local coordinate system (if you set the base at an arbitrary point).

● Disadvantages of Single Reference Station RTK

• Initial costs are high due to the base GNSS receiver, radios, tripods, batteries, and so on, and transporting and installing the equipment requires effort. Setting up the base on site takes time before work can begin.

• Accuracy deteriorates significantly if you are too far from the base. At distances of tens of km or more, corrections cannot keep up and it becomes practically unusable. For surveying wide areas, you must divide the area and repeatedly relocate the base.

• Maintenance and management of the base are required. Securing installation locations, preventing theft, battery replacement, and obtaining known coordinates for observation points (or placing the base on known points) all require expertise and management costs.

● Advantages of Network RTK

• No need to provide your own base stations; you can start immediately with only a single rover. Because there is no on-site equipment setup, preparation time is greatly reduced.

• Stable accuracy can be maintained across wide areas. Virtual reference stations are always generated nearby, so accuracy degradation is small even over tens of kilometers, making it suitable for continuous surveying across large areas.

• Efficient for projects with many measurement points or much movement. There is no need to relocate bases by area, making it suitable for operations where one person moves around and measures many locations.

● Disadvantages of Network RTK

• Receiving correction information via the internet is essential, so you depend on communications. In sites without mobile coverage you cannot use the service and will need a conventional base station.

• There are running costs. Service fees for network RTK and communication charges are incurred, and total cost increases with longer-term or wider-area use.

• Depending on the service, the reference coordinate system may be fixed to a global geodetic frame (in Japan, JGD2011), so if you need to work in a local coordinate system, coordinate transformation on site may be necessary.

Considering the above, conventional RTK is suitable for repeated surveys within a limited area or in locations without communications. Conversely, network RTK is powerful for wide-area surveying or tasks involving a lot of movement where one person wants to measure many points efficiently. Recently, due to cost and convenience, network RTK usage is becoming mainstream, but it is important to choose the appropriate method according to site conditions.

From the perspective of one-man surveying, network RTK makes true single-person operation easier because you do not need to handle an on-site base. Conversely, for single-person work with standalone RTK, you must consider the effort to install and remove the base yourself and the risks of leaving base equipment unattended during operations.

Key Points for Successful One-Man Surveying

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

• Preplanning and preparation: Because you work alone, planning is crucial. Understand travel routes and measurement locations and create an efficient route plan. Also ensure device charge levels, prepare spare batteries, and confirm communication environments.

• Ensuring safety: Surveying in hazardous locations or sites with heavy machinery increases risk if you are alone and cannot watch your surroundings. Implement safety measures such as cordoning off work areas or asking a third party to watch, as needed. Avoid high places or night work if possible; if you must work alone, equip yourself with helmet, lights, and other safety gear.

• Securing communication means: When working alone there may be no one nearby to call for help. Make sure you can contact others via mobile phone or radio, and consider regular status check-ins to improve safety management.

• Ease of equipment handling: Since you will transport and operate equipment solo, use lightweight and simple configurations to reduce the burden. Small GNSS receivers and smartphone-linked apps are becoming available, enabling intuitive operation by one person.

• Skill acquisition: Train sufficiently before working alone. If you are not familiar with operating RTK receivers and software, you may struggle to handle problems alone on site. Practice procedures in safe environments and understand device behavior before the real job.

Introduction to Simple Surveying with LRTK

As described above, the spread of network RTK and smaller devices has made one-man surveying a realistic option. 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." By combining a dedicated device with a smartphone, centimeter-level positioning (half-inch accuracy) can be performed easily. The small terminal, weighing approximately 125 g and about 13 mm (0.51 in) thick, integrates a GNSS antenna, receiver, battery, and communication module; attaching it to a smartphone and launching an app starts high-precision positioning.

Compared with conventional RTK equipment, no cable connections or complicated settings are required, and it is intuitive even for those without surveying expertise. It links to a smartphone via Bluetooth or Wi-Fi, automates correction reception and cloud uploading of positioning data, and dramatically improves field efficiency. The higher-end LRTK Pro2 supports Japan’s QZSS-provided centimeter-level augmentation service (CLAS) and can achieve high-precision positioning from satellite augmentation signals alone even in mountain areas without mobile coverage. The LRTK series is also configurable to meet Ministry of Land, Infrastructure, Transport and Tourism i-Construction standards, making it an attractive solution to support DX (digital transformation) in the construction industry from the field.

Using LRTK, the convenience of network RTK and the latest GNSS technology are realized in the palm of your hand, and the era in which "anyone can safely perform RTK surveying alone" is at hand. Even in sites that demand high precision for surveying and construction, LRTK enables tasks that previously required multiple people to be done quickly by one person. As a tool to expand the possibilities of one-man surveying, consider simple surveying with LRTK.

FAQ

Q1. Is there a difference in accuracy between RTK and network RTK (VRS)? A1. The basic positioning accuracy is comparable; both can achieve centimeter-level positioning (half-inch accuracy) when properly operated. However, conventional RTK accuracy degrades as the distance from the base increases, whereas network RTK maintains a virtual reference point 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 and log into a correction information distribution service (Ntrip server) to receive data. In many cases, a paid correction service subscription is required. Check mobile coverage in your work area in advance and complete necessary communication contracts and service registrations.

Q3. What should I be careful about when doing RTK surveying alone? A3. When surveying alone pay attention to both safety and efficiency. For safety, avoid hazardous locations where possible and consider safety equipment or third-party support if necessary. For efficiency, identify measurement point locations in advance and optimize the measurement order, and make equipment compact and easy to carry. Always ensure a means of external communication and prepare for emergencies. To prevent overlooking measurement data or recording errors, frequently check measurement results during work and back up data as needed.

Q4. What are the advantages of installing your own reference station? A4. Installing your own reference station allows stable high-precision positioning without relying on external services. After the initial investment, running costs can be lower, and you can perform RTK via radio even in areas without mobile coverage. Placing a base on a known point gives you immediate access to absolute coordinates in a global geodetic frame, while placing it on an arbitrary point makes working in a local coordinate system easier, providing flexibility.

Q5. What is LRTK? A5. LRTK is a portable, easy-to-use new RTK positioning solution. It combines a small device that fits in a pocket with a smartphone app, enabling centimeter-level surveying (half-inch accuracy) by anyone. Preparation and operation are much simpler than with conventional equipment, strongly supporting solo surveying. It is designed to be usable without specialized knowledge, lowering the barrier to RTK surveying. Higher-end models can achieve high-precision positioning even in mobile-dead mountain areas using satellite augmentation signals, enabling stable positioning in various sites.

Q6. Which should I choose: single RTK or network RTK? A6. The choice depends on site environment and use case. For a limited-area site requiring consistently high accuracy, installing your own reference station (single RTK) may be stable and manageable. Conversely, for surveying while moving over wide areas or in regions with good communication infrastructure, network RTK is convenient and efficient. Consider initial investment and running costs as well. It is advisable to conduct on-site trial runs (demos) before introduction to verify communication conditions and accuracy. Decisions based solely on theoretical comparison are not recommended; field testing reveals effects of surrounding terrain and communications and helps prevent problems after deployment.