RTK Accuracy from On‑Site Professionals: How Precision Brings Peace of Mind and Efficiency

Table of Contents

• What is RTK accuracy?

• The peace of mind RTK accuracy brings

• Efficiency gains from RTK accuracy

• Simple surveying with LRTK

• FAQ

Professionals working on site feel the importance of “accuracy” in positioning and surveying every day. “A deviation of just a few centimeters can lead to a major problem” — this is something many site supervisors and surveyors emphasize in unison. In practice, if the foundation position of a construction project is off by only a few centimeters, it can affect the safety of the entire structure or cause major rework in later stages. Some veteran technicians even say, “Thanks to high accuracy, worries about surveying mistakes have disappeared and on‑site safety management has improved dramatically,” showing how directly accuracy ties to peace of mind on site.

In recent years, the technology bringing this “centimeter‑level accuracy” to the field is RTK (Real Time Kinematic). RTK corrects satellite positioning errors such as those from GPS in real time, enabling location determination with extremely high accuracy that was difficult to achieve before. While standalone GPS can have errors of several meters, RTK can reduce errors to within a few centimeters — a completely different order of magnitude. As a result, the increased positioning accuracy brings large benefits of “peace of mind” and “efficiency” to field operations. This article explains how RTK works, its accuracy, and the benefits high accuracy brings to the field, from a professional’s perspective. At the end of the article, we also introduce LRTK, a solution for easily starting RTK surveying.

What is RTK accuracy?

First, let’s review how high‑precision positioning with RTK is achieved. RTK (Real Time Kinematic) is a positioning technique that uses two GNSS receivers to correct positioning errors in real time and obtain centimeter‑level accuracy. Specifically, one receiver is installed at a known coordinate as a “base station,” and the other is used at the measurement point as a “rover,” operated as a pair. The base station calculates the difference between its known true position and the position obtained from the satellites, and transmits that error information via radio or the Internet. The rover applies the received correction information to its own positioning data, canceling out the errors in satellite positioning to compute a highly accurate position. Because error correction is performed in real time, centimeter‑level positioning results can be obtained on the spot immediately.

The positioning accuracy achievable with RTK is approximately ±1–2 cm (±0.4–0.8 in) horizontally, and on the order of a few centimeters to a dozen or so centimeters vertically when properly operated in an open sky environment. This level of accuracy sufficiently meets the strict precision requirements demanded in surveying and construction. For example, if centimeter accuracy is guaranteed, layout (batter board) staking for buildings and quality control of earthworks in civil engineering can be carried out with confidence. On the other hand, maximizing RTK’s benefit requires certain conditions: a shorter baseline (distance) between the base and rover improves correction effectiveness, an open sky to receive satellite signals well, and sufficient observation time until a stable FIX solution (an integer ambiguity resolution in RTK) is obtained. If these conditions are met, RTK’s strength is its ability to measure positions with accuracy previously unattainable by conventional methods. Because RTK can provide centimeter accuracy in real time, it is often described as a “survey instrument that can measure while moving,” highlighting its revolutionary nature.

In Japan, infrastructure supporting RTK is also becoming more robust, such as the Geospatial Information Authority’s GNSS reference station network and augmentation signals from the quasi‑zenith satellite system “Michibiki” (CLAS). With these developments, users can obtain correction information via networks without setting up their own base station, making it easier to perform centimeter‑accuracy positioning. In other words, the era in which anyone can use RTK’s high accuracy is arriving.

The peace of mind RTK accuracy brings

One of the greatest advantages of high positioning accuracy is the enhancement of peace of mind on site. “Peace of mind” here has two meanings. One is confidence in the reliability of the data. With centimeter‑level positions from RTK, you can be confident that surveying results and as‑built data are correct. For example, when surveying the placement of curbstones in road construction, RTK positioning keeps errors within about 1–2 cm (0.4–0.8 in), allowing precise installation according to the design. In situations where conventional GPS could be off by several meters, there was lingering concern after construction about measurement errors, but high‑precision positioning removes that worry. From a site supervisor’s perspective, construction backed by trustworthy measurement data allows for confident approval in inspections and quality control. The reassurance that “there is no need to doubt the survey results” positively affects overall morale and the certainty of work on site.

The other form of peace of mind is ensuring safety. GNSS surveying such as RTK offers safety advantages by reducing worker burden and hazards compared to traditional methods. Consider surveying steep slopes in mountainous areas or disaster sites. With conventional total station surveying, heavy equipment must be carried into difficult terrain and multiple people are needed to take measurements — operations that carry constant accident risk on high or unstable slopes. RTK allows measurements near the target from a location with an open sky and, in some cases, surveying without sending people into hazardous areas by combining RTK with drones or robots. This greatly reduces situations in which workers are exposed to danger. Shorter working times also reduce night shifts and long working hours, lowering the risk of human error and accidents. Professionals on site report that “RTK has reduced the number of dangerous surveys and dramatically decreased close‑call incidents.” This is a clear example of how pursuit of accuracy directly contributes to safety.

Efficiency gains from RTK accuracy

RTK’s high precision also contributes significantly to improving on‑site efficiency. Why does improved accuracy itself lead to higher efficiency? One reason is the reduction of rework. When surveying or construction has large errors, discrepancies with design may be discovered later, requiring redo work. For example, if the elevation of a development site is surveyed with low accuracy, insufficient or excessive filling/cutting may go unnoticed during construction, leading to rework later. If accurate measurements are taken from the start with RTK, such rework can be prevented, resulting in shorter schedules and lower costs. One site reported that “after introducing RTK, the number of remeasurements dropped and daily work quantity increased significantly,” a good example of how high accuracy boosts productivity.

RTK’s immediacy also contributes to efficiency. Because high‑precision positioning is obtained in real time, data can be used on the spot. Previously, survey data had to be taken back for analysis and drafting, and if problems were found, crews had to return to the field — causing time lags. By combining RTK with tablets or smartphones, measurement results can be checked immediately on drawings or 3D models on site and shared with the office via the cloud. This greatly reduces “waiting time” and “work taken home,” enabling projects to proceed at a pace that makes the site and office feel closer. Site supervisors also note that “being able to check as‑built data as a color‑coded map on the spot means we can issue immediate correction instructions.” In terms of speeding decision‑making, RTK surveying, which combines accuracy and immediacy, is a key to improving efficiency.

Moreover, in the construction and surveying industries facing severe labor shortages, RTK directly supports labor savings. Survey tasks that formerly required two to three people can now be done by one person, and the introduction of high‑precision equipment helps mitigate skills transfer challenges caused by the retirement of veteran technicians. This trend aligns with national productivity initiatives such as “i‑Construction,” and the spread of centimeter‑level positioning is driving on‑site digital transformation (DX). In other words, RTK is making it possible to operate efficient, high‑precision work with fewer personnel.

Centimeter‑level positioning technology is also spreading beyond construction to fields like agriculture and infrastructure management. For example, in precision agriculture with autonomous tractors, RTK’s high accuracy enables implements to run with centimeter‑level precision, reducing wasted overlap. Using RTK to manage buried positions of water, sewer, and gas pipes allows accurate mapping of pipelines and improves maintenance efficiency and safety. In this way, the efficiency and quality improvements based on RTK accuracy create significant value across many types of job sites.

Simple surveying with LRTK

Even if you understand RTK’s advantages, you may worry that implementation requires expensive equipment or advanced expertise. Indeed, until not long ago, GNSS receivers capable of centimeter‑level positioning were very costly and required specialized training to operate. However, technological innovation has made RTK surveying remarkably easier. One noteworthy development is the emergence of smartphone‑based simple surveying.

For example, by combining a small RTK receiver that attaches to a smartphone with a dedicated app, anyone can use their smartphone as a surveying instrument and achieve centimeter‑level positioning. This is exactly the solution called LRTK. LRTK consists of a thin, compact GNSS receiver and a smartphone app, used by attaching the receiver to an iPhone or Android device. By simply attaching a receiver weighing only about a hundred‑odd grams to a smartphone, RTK surveying that once required specialized instruments can be performed in the palm of your hand. The app handles complex settings automatically, so the user only needs to tap a button at the point to be measured. It is designed to be intuitive enough that no special knowledge is required.

Intuitive surveying tools bring additional benefits to the field. Because veterans and newcomers can share data on the same system, it aids skill transfer and promotes teamwide DX.

By using easy RTK tools like LRTK, site staff can take on surveying tasks that previously required specialists. Replacing routine as‑built checks and layout tasks with simple surveying alone reduces waiting time for surveys and frees up time for other duties. Sharing data collected on site to the cloud immediately also eliminates the need to return to the office. Start by adopting high‑precision simple surveying for familiar tasks to take the first step toward digitalization. Why not experience RTK technology that balances trust in accuracy with work efficiency at your own sites?

FAQ

Q: What do I need to use RTK positioning? A: To perform high‑precision RTK positioning, you need an RTK‑compatible GNSS receiver and a reference station that provides correction information. The basic configuration is a pair consisting of a rover at the measurement point and a base station installed at a known point. However, network‑based RTK, which allows users to receive correction services via nationwide reference stations or commercial correction services, is now mainstream; you don’t have to prepare your own base station. With correction data received over the Internet, centimeter‑level positioning can be started as long as the rover receiver is available. While rovers have traditionally used dedicated terminals, ultra‑compact receivers that pair with smartphones have recently appeared. For example, using an LRTK device that attaches to a smartphone and its dedicated app turns your smartphone into a high‑precision surveying instrument.

Q: Can RTK positioning be used where mobile phone coverage is unavailable? A: In sites without Internet connectivity, such as mountainous areas or remote islands, network‑based RTK services cannot be used. As an alternative, you can set up your own local base station and send correction data via radio; if the rover and base station communicate directly by radio, RTK positioning is possible offline. Also effective is Japan’s quasi‑zenith satellite system “Michibiki” CLAS augmentation service. With a CLAS‑compatible receiver, you can receive correction information directly from satellites, maintaining centimeter‑level positioning even in areas without mobile coverage (some higher‑end LRTK models support CLAS reception). Positioning data obtained offline are stored on the device and can be synchronized to the cloud later when connectivity is available.

Q: How accurate is RTK positioning? A: When conditions are favorable, RTK positioning accuracy is about 1–2 cm (0.4–0.8 in) horizontally and a few centimeters to around 10 cm vertically. In practice, when stationary in an open sky, errors are confirmed to be within that range. By using averaging (accumulating data over a certain time and averaging), sub‑1 cm (<0.4 in) errors can be achieved. However, accuracy varies with the surrounding environment and satellite reception conditions. Signals reflected by trees or buildings can degrade accuracy, and RTK does not function where satellites cannot be captured, such as inside tunnels. Also, initial acquisition may take several tens of seconds for the RTK solution to stabilize. Despite these constraints, once a stable FIX solution is obtained, centimeter‑level accuracy can be maintained continuously.

Q: Are operation and setup difficult? Can beginners use it? A: Modern RTK surveying systems are designed to be simple and user‑friendly for beginners. Especially for devices that connect with smartphones, many specialized settings are handled automatically by the app, allowing users to start using them with the same ease as map apps. You can record a point by pressing a button, and acquired data are automatically saved and organized, which is more reliable than handwriting in a field book. Many first‑time RTK users say, “It was easier than I thought.” Advanced functions (coordinate system settings, switching positioning modes, etc.) can be adjusted as needed, but basic measurements can be learned quickly without special knowledge.

Q: Is the cost worth the benefits? A: The price of RTK‑capable equipment has been falling in recent years, lowering the initial investment barrier compared to the past. There are also more rental and subscription options. More importantly, the efficiency improvements from RTK are significant: labor cost savings from reduced staffing and shorter working hours, schedule reductions by preventing rework, and reductions in material waste and effort from fewer mistakes — all leading to lower on‑site costs. If the daily time spent on surveying is halved, that time can be reallocated to other tasks, raising overall productivity. From both quality improvement and efficiency perspectives, RTK can offer value that justifies the investment.

Q: What is LRTK? A: LRTK is the product name for a smartphone‑attachable RTK positioning device and app service developed by Reflexia Inc. By attaching a thin, lightweight GNSS receiver to a smartphone and using the compatible app, you can turn an iPhone or Android device into a centimeter‑accuracy surveying instrument. The receiver, weighing approximately 120–130 g, houses an antenna, GNSS chip, communication module, and battery, making it easy to carry. Compared to conventional fixed GNSS receivers, LRTK is overwhelmingly more convenient and intuitive to use, lowering the barrier for non‑specialists to perform surveying on site. With LRTK, anyone can experience high‑precision positioning “anytime, anywhere,” making it a strong ally for workplace reform and DX initiatives on the job site.