Contents

• Introduction

• What is RTK?

• Benefits of RTK

• Challenges when introducing RTK

• Minimum knowledge field members should learn

• Ways to reduce RTK training costs

• Simple surveying with LRTK

• FAQ

Introduction

RTK (Real-Time Kinematic) positioning is a technique that uses satellite positioning with corrections applied to obtain centimeter-level high-precision positions in real time. In recent years, RTK has been increasingly used not only in surveying and construction, but also in various outdoor fields such as railway and highway infrastructure inspection, drone surveying, and autonomous farming.

The benefits brought by high-precision position information are tremendous, but when introducing new technology on site, people often worry, “Will we be able to use this well?” or “It looks like it will take time and effort to learn.” RTK positioning in particular has a strong technical impression, and many assume that teaching all field members would be difficult and that training costs (the time and effort required for staff to acquire the skills) will be high. For that reason, some hesitate to introduce high-precision technology.

But is RTK training really that costly? What exactly is the “minimum knowledge” required on site? This article explains that. By focusing on key points and covering the basics, and by using user-friendly tools, even beginners can use RTK on site without excessive burden. Finally, we introduce simple surveying using the smartphone positioning solution LRTK, which further lowers the barrier to RTK use.

What is RTK?

RTK is a technique that achieves high-precision positioning by correcting position errors using two GNSS receivers. One is set as a base station at a known position, and the other is a rover carried to the target to be measured. Both receivers receive signals from the same satellites simultaneously, and the base station calculates error information from the difference between its known accurate position and its received data. This correction information is transmitted to the rover in real time, and by applying it to the rover’s observations, positioning errors that are usually several meters can be reduced to a few centimeters.

Standalone positioning (using a single GNSS receiver) typically has errors on the order of 5–10 m (16.4–32.8 ft), but RTK achieves “relative positioning” to the base station and cancels error factors in satellite signals, resulting in extremely high accuracy—about 1–2 cm (0.4–0.8 in) horizontally and a few centimeters vertically. Because corrections are applied in real time, a major feature is that you can obtain high-precision coordinates on site immediately without special post-processing.

Recently, network RTK, which allows you to obtain correction information without setting up your own base station, has become widespread. This method receives correction data via mobile communications from reference stations such as those provided by the Geospatial Information Authority of Japan, allowing centimeter-level positioning almost anywhere in Japan with network coverage. In addition, by using CLAS, the augmentation signal transmitted by Japan’s Quasi-Zenith Satellite System, high-precision positioning can be performed even in mountainous areas without internet coverage. Advances in technology have thus made RTK positioning more accessible than before.

Benefits of RTK

Introducing RTK provides the following benefits on site:

• Dramatic improvement in positioning accuracy: Ordinary GPS positioning can be off by several meters, but RTK allows positions to be determined with centimeter accuracy. This makes it possible to carry out tasks that require precision, such as laying out structures and managing elevations, with confidence.

• Greatly improved work efficiency: High-precision surveying can be done in a short time, streamlining tasks that previously required a surveying crew or multiple people. One person can walk with a GNSS rover and measure wide areas, and guiding heavy equipment or managing as-built conditions can be done in real time. For example, machine guidance for GNSS-equipped construction equipment, which provides guidance to the operator, is possible thanks to RTK’s high precision.

• Real-time decision making: Because accurate coordinates are available on the spot, there is no need to bring data back to the office for processing. You can immediately compare with design drawings or decide on additional measurements and respond on site.

• Improved safety: GNSS positioning can measure even without line of sight, so measurements can be taken from a distance in hazardous locations such as cliffs or retaining walls. Equipping drones with RTK also enables surveying of areas where people cannot enter, reducing risk to workers.

• Support for new technology and automation: RTK is the foundation for next-generation technologies such as autonomous driving and automated control of construction machinery. Advanced examples enabled by RTK—robot tractors in agriculture and unmanned drone surveying—are increasing. Adopting high-precision positioning directly contributes to promoting DX (digital transformation) on site.

Challenges when introducing RTK

Although RTK delivers excellent results, several challenges are pointed out when introducing it on site. From an equipment standpoint, initial investment tends to be high due to high-precision GNSS receivers, base station equipment, and communication infrastructure. High-performance GNSS equipment can be expensive, which is a reason some small- to medium-sized sites hesitate to adopt it. You also need to consider service fees for positioning corrections and maintenance costs.

Moreover, hurdles in personnel and training cannot be ignored. The construction industry is facing a shortage of surveying and construction management personnel and an aging workforce, making training people to handle new technology a pressing issue. RTK equipment operation and GNSS-specific knowledge require specialized skills, and traditionally experienced surveyors or technicians handled these tasks. Training staff to operate on site is essential, but it is not easy to train newcomers from scratch amid busy work schedules. If insufficient time is allocated for training and equipment is taken to site prematurely, configuration mistakes or measurement errors can occur, leading to poor accuracy and rework.

For example, when setting up a base station, it must be placed on an accurate known point, but inadequate knowledge can lead to careless placement and overall offset in measurement data. There are cases where rovers were measured with the pole tilted because the operator didn’t know the basic requirement to hold the pole vertical, resulting in large errors. Human errors due to insufficient training—such as antenna height input mistakes, or recording questionable data without checking satellite count or Fix status—are common on site.

Thus, when introducing RTK there are two cost aspects: “cost to procure equipment” and “cost for people to use it.” However, the latter—training cost—can be significantly reduced with ingenuity. The next section covers the basic knowledge field members should minimally understand and points to reduce training burden.

Minimum knowledge field members should learn

You do not need expert-level deep knowledge to use RTK on site. Below are the basic points field staff should at minimum understand.

• Accurate setup and coordinate setting of the base station: If you set up your own base station, install it on a known point (control point) with minimal error, and input accurate coordinate values before starting positioning. Neglecting this will shift all measurement results, so the base station’s installation position and initial settings are the highest-priority items.

• Keep the rover pole vertical at all times: The pole (or staff) with the GNSS receiver should be kept vertical with a bubble level during measurement. If the pole is tilted, height errors increase and accurate positions cannot be obtained.

• Prevent antenna height input errors: Measure the height to the rover antenna (instrument height) correctly each time and set it in the receiver or software. When changing pole length or using a tripod, be careful not to leave the previous value by mistake.

• Check satellite count and Fix status: Before starting measurement, confirm that a sufficient number of satellites are being tracked and that the solution is not float but Fix. Only when a Fix solution is obtained do you get centimeter-level accuracy. Never measure while the solution is unstable—always check that the display or indicator showing “FIX” is on.

• Consider obstructions and radio environment: RTK positioning uses satellite signals above, so it performs best in open skies. Tall buildings or trees nearby can block signals or cause multipath (reflections), degrading accuracy or preventing Fix from being maintained. When positioning, secure clear sight lines and pay attention to antenna placement; if necessary, remeasure at a location with fewer obstructions.

• Coordinate system consistency: Coordinates obtained by GNSS are in global geodetic systems (such as WGS84), but construction and surveying sites may use the Japanese Geodetic Datum (JGD2011) or a local coordinate system. Set the coordinate system on the positioning device to match the project to avoid discrepancies when comparing deliverables with drawings. There have been cases where data were delivered in a global geodetic system and were off by tens of meters relative to drawing coordinates. Modern equipment and services often have automatic coordinate transformation, but habitually checking by comparing observed values to known points after measurement is also useful.

Ways to reduce RTK training costs

If you keep the basic rules above, field members can handle RTK surveying. The following measures are also effective to further reduce training effort.

• Standardize procedures: Create internal manuals for RTK equipment setup and measurement procedures so that anyone can follow a consistent process. Prepare checklists that document each confirmation item—“confirm base station coordinates,” “hold the pole vertical,” “reset antenna height,” “check FIX status”—so newcomers can complete tasks without omissions.

• Use hands-on training and OJT: Don’t rely solely on classroom learning; conduct training where staff actually handle RTK equipment on site or in a simulated environment. Initially have an experienced operator demonstrate, then let the trainee perform under supervision in an OJT format. After a few site experiences they will grasp the workflow, so early practical participation accelerates learning.

• Choose intuitive tools: Where possible, adopt user-friendly, intuitive RTK systems to reduce training costs. Some dedicated devices have many settings that take time to master, but recently RTK apps that run on smartphones and tablets have appeared. If measurements can be performed simply by following menus and the screen is easy to read, beginners can get comfortable in a short time.

• Develop a “site surveying lead”: Not everyone needs advanced skills, but it’s useful to cultivate a team member who is knowledgeable about RTK. This person can lead training for others and provide on-site support during problems, improving overall training efficiency. Aim to circulate know-how internally so skills accumulate within the team without relying on external training.

Simple surveying with LRTK

A representative example of the “user-friendly tools” mentioned above is LRTK, an RTK system that uses smartphones. LRTK attaches a small GNSS receiver to a smartphone and manages positioning and data via an app. Unlike traditional dedicated equipment, operation is completed on a familiar smartphone screen, allowing users to start surveying without being aware of complicated device settings. Since you can use a phone you already have, initial investment is lower and the barrier to adoption is reduced.

For example, by following the app menu you can receive correction information from a base station and switch positioning modes or start recording with a single tap. Positioning status (Fix/Float) is shown with colored icons for easy recognition, and coordinate systems can be automatically converted to the Japanese geodetic system, so users don’t need to worry about detailed calculations or adjustments. Designed so field staff can intuitively operate it like a smartphone app, LRTK greatly reduces training costs. As a result, new hires and people transitioning from other industries can learn operation in a short time and become productive on site.

LRTK does more than measure positions: by linking with the smartphone’s camera and sensors, it provides comprehensive support for field work. You can take photos and save notes at each point while positioning, and easily share data with the team in the cloud. When data and know-how are shared internally, reliance on specific veterans decreases and the team’s overall skill level becomes more uniform, improving training efficiency. LRTK can also continue high-precision positioning even where there is no communication infrastructure by directly receiving CLAS signals from Japan’s Quasi-Zenith Satellite System. Therefore, it performs well in disaster-affected sites with no communications or in mountainous surveys. Precision positioning that was previously left to specialized surveying departments is becoming “simple surveying anyone can do” thanks to LRTK. As a trump card for embedding high-precision positioning on site, LRTK supports both training reduction and lower operational costs. If your site hesitates over RTK adoption because training seems daunting, using a simple surveying system like LRTK can substantially reduce the burden and enable the introduction of high-precision technology. Actively adopt modern tools to promote DX on site while keeping training costs down.

FAQ

Q: What is RTK? A: A technique that corrects GNSS (satellite positioning) errors to perform high-precision positioning in real time. Two receivers—a base station and a rover—simultaneously observe satellites, and correction information from the base station is used to determine positions to within a few centimeters.

Q: How accurate is RTK positioning? A: Under good conditions, horizontal positions are on the order of about 1–2 cm (0.4–0.8 in), and vertical errors are also within a few centimeters. It is far more accurate than standalone GPS positioning and is sufficient for precise construction and surveying. However, accuracy can decrease depending on the surrounding environment and satellite geometry.

Q: Can inexperienced people handle RTK? A: Yes. If they learn basic operating procedures and precautions, inexperienced people can perform RTK surveying. By following the points in this article—keeping the pole vertical, entering antenna height correctly, and confirming Fix status—non-experts can use centimeter-accuracy positioning on site. Smartphone-app-based RTK devices have also appeared recently, making intuitive operation easier for beginners.

Q: What is required to introduce RTK? A: Generally, an RTK-capable high-precision GNSS receiver and a means of obtaining correction information are required. If you set up your own base station, you need two receivers (one for the base and one for the rover) and wireless communication equipment; if you use network RTK, one rover receiver and a communication line (mobile network, etc.) suffice. In the latter case, you subscribe to correction services provided by the Geospatial Information Authority or private providers. With LRTK using a smartphone, preparation is complete with a smartphone, a small receiver, and an app, and it can continue positioning using CLAS satellite signals even outside network coverage.

Q: What is LRTK? A: LRTK is a name for a high-precision positioning and simple surveying system that uses smartphones. A small GNSS receiver is combined with a smartphone and a dedicated app to perform RTK positioning. It enables centimeter-level positioning without specialized equipment, and operation is completed on the smartphone, making it easy for beginners. It also offers cloud integration and AR displays, and is attracting attention as a DX tool for the field.

Q: Do you need qualifications or licenses to use RTK equipment? A: Basically, no special public license is required just to operate RTK positioning. Anyone can operate it after training. However, when using radio transmissions from a base station, radio law licensing procedures may be required in some cases (many commercial RTK devices use low-power radio or the internet, so no license is needed). Also, officially certifying surveying deliverables requires national surveying qualifications such as a surveyor’s license, but for using RTK for on-site accuracy control, internal training is usually sufficient.