How to Choose an RTK-Capable GNSS Receiver: A Checklist to Avoid On-Site Mistakes

Table of Contents

• What is RTK? Why do you need a high-precision GNSS receiver

• 10-point checklist for selecting an RTK-capable GNSS receiver - 1. Supported satellite systems (GPS, GLONASS, Galileo, QZSS) - 2. Supported frequency bands (L1/L2/L5, etc.) - 3. Correction data methods (RTK networks, Ntrip, etc.) - 4. Positioning accuracy (horizontal accuracy, vertical accuracy) - 5. Communication methods (radio, Bluetooth, SIM card support) - 6. Internal memory and data logging - 7. Environmental resistance (dustproof/waterproof, operating temperature range) - 8. Battery runtime - 9. Weight and size (portability) - 10. Software and app integration

• Simple surveying achievable with LRTK

• FAQ

What is RTK? Why do you need a high-precision GNSS receiver

In recent years, the importance of RTK-capable GNSS receivers (high-precision GNSS positioning systems) has grown dramatically at construction, civil engineering, and infrastructure maintenance sites. While calculating positions with the GPS built into car navigation systems or smartphones is indispensable for everyday tasks, typical standalone GPS positioning accuracy remains on the order of several meters and, in some cases, can produce errors of around 10 m. For construction management and surveying, where millimeter-level accuracy is often required, such errors are insufficient. This is where high-precision positioning known as RTK positioning (Real-Time Kinematic) comes in. By using an RTK-capable GNSS receiver, positional errors can be reduced to a few centimeters, achieving the high precision needed for surveying and construction.

RTK positioning operates two GNSS receivers simultaneously: a base station with known precise coordinates and a rover that observes while moving. Because the base station’s exact position is known, it can compute various error components contained in the GNSS satellite signals in real time. The base station then transmits that correction information to the rover via communication, and the rover applies the corrections to its own positioning results. This cancels errors that standalone GPS cannot remove and enables centimeter-level precision.

While RTK positioning requires dedicated equipment and procedures, it substantially improves productivity on civil engineering and surveying sites. Introducing RTK technology can dramatically increase work efficiency compared to traditional methods such as total stations (electronic distance meters), and in some cases allow a single person to complete extensive surveying tasks. Various RTK-capable GNSS receivers from many manufacturers are now available, with a wide range of functions and performance. Which device will avoid on-site failures? Below are the 10 key points for selecting an RTK receiver. Carefully check each point and choose the model that best fits your operations.

10-point checklist for selecting an RTK-capable GNSS receiver

1. Supported satellite systems (GPS, GLONASS, Galileo, QZSS)

First, check which satellite positioning systems the RTK receiver supports. GNSS satellites include the U.S. GPS, Russian GLONASS, European Galileo, China’s BeiDou, and Japan’s quasi-zenith satellite system “QZSS” (Michibiki). The more types of satellites the receiver can receive, the more satellites will be visible overhead, improving positioning stability in urban canyons or mountainous areas. Especially for use within Japan, support for QZSS (Michibiki) is a significant advantage. Michibiki satellites are placed in orbits that keep them over Japan for extended periods, so at least one is typically visible overhead, which helps improve accuracy even in mountainous regions.

Modern high-precision GNSS receivers commonly support multi-GNSS reception, not only GPS+GLONASS but also Galileo and BeiDou. Considering future increases in satellite signals and numbers, choose a model that supports as many satellite systems as possible.

2. Supported frequency bands (L1/L2/L5, etc.)

GNSS satellite signals are transmitted on multiple frequency bands (L-bands). L1 (around 1.5 GHz) is typical, but for higher-precision positioning, multi-frequency reception that includes L2 and L5 in addition to L1 is important. Dual-frequency (L1+L2) receivers can cancel ionospheric errors, providing better accuracy than single-frequency reception and reducing time to initialize (resolve integer ambiguities).

Recently, triple-frequency receivers that support the new civilian GPS L5 signal have also appeared. The L5 signal has higher power and wider bandwidth than previous signals, making it more resistant to multipath (reflections from buildings or the ground) and radio interference, thus improving positioning reliability. For example, the latest receivers can simultaneously receive multiple bands such as GPS L1/L2/L5, GLONASS G1/G2, Galileo E1/E5, and BeiDou B1/B2. If possible, choose a model that also supports L5 to be future-proof as GPS L5 becomes fully operational.

3. Correction data methods (RTK networks, Ntrip, etc.)

In RTK positioning, a means of transmitting correction data from the base station to the rover is essential. The correction data transfer method is a key consideration when selecting a receiver. Broadly speaking, you can either set up your own base station and communicate via radio, or use an internet-based network RTK (VRS, etc.). With national control point networks and private correction services now well established, many sites obtain correction data over the Internet using the Ntrip protocol. Therefore, confirm whether the receiver has Ntrip client functionality and can receive corrections in real time via mobile data.

However, at tunnel construction sites or remote mountain surveys where Internet connectivity is unstable or unavailable, the traditional RTK method of directly linking a privately deployed base station and rover via radio can be effective. Some receivers include internal UHF radio modems to directly communicate between base and rover, and some support external radios. Depending on your operating environment, check whether the receiver supports network RTK, direct radio communication using your own base station, or both. Also ensure the receiver supports correction data formats suitable for your use, such as RTCM3 or CMR. In some countries or regions, subscription fees for correction services may apply, so factor that into your budget.

4. Positioning accuracy (horizontal accuracy, vertical accuracy)

Always verify that the catalog-listed positioning accuracy specifications meet your requirements. RTK receiver accuracy is usually specified separately for horizontal (planar) and vertical (height) components, often in the form “error = X mm + Y ppm.” For example, a high-performance RTK receiver might list “fixed solution (RTK Fix) accuracy: horizontal 8 mm + 1 ppm, vertical 15 mm + 1 ppm (RMS).” PPM (parts per million) denotes a distance-proportional error component that increases with the baseline length from the base station. In this example, even at 10 km from the base station, horizontal error would be about 8 mm + 10 km × 1 ppm = approximately 18 mm.

Manufacturers may express these errors as RMS (one standard deviation) or as 2-sigma (95% confidence interval), but in any case the numbers indicate sub-centimeter to centimeter-level accuracy. Note that vertical accuracy is typically about 1.5 times worse than horizontal accuracy. Also consider differences between models in time to initialize (resolve integer ambiguities) and time to recover a fixed solution (Fix) after a loss. Even receivers with similar catalog specs can differ in stability under real-world conditions (e.g., urban multipath or canopy). If possible, review evaluation data from actual equipment or user reviews.

Translated units in this section:

• Fixed solution example: horizontal 8 mm (0.31 in) + 1 ppm, vertical 15 mm (0.59 in) + 1 ppm (RMS)

• Example calculation: even at 10 km from the base station, horizontal error ≈ 8 mm (0.31 in) + 10 km × 1 ppm = approximately 18 mm (0.71 in)

5. Communication methods (radio, Bluetooth, SIM card support)

Communication between the base station and rover is critical for RTK. Check the receiver’s supported communication methods. As mentioned above, base⇔rover communication can be via dedicated radio (UHF) or via the Internet. Many surveying RTK receivers include built-in UHF radio modems so that, with the proper radio license, you can receive correction data in real time even in mountainous areas without Internet service (in Japan, operation of UHF fixed stations requires filing or licensing for digital simple radio or other applicable radio regulations).

For network RTK, the rover requires mobile Internet access. Therefore, more receivers now include a SIM card slot or built-in LTE module. A receiver with built-in SIM support can connect to correction services by itself. Non-SIM receivers can share a tablet/PC or smartphone’s connection via Bluetooth or Wi‑Fi.

Bluetooth is standard on almost all receivers, allowing wireless connection to smartphones or dedicated data collectors. Some models also provide a Wi‑Fi access point so settings and data transfer can be managed from a browser on a smartphone. Imagine how you will use the device on site and choose a receiver with the necessary communication interfaces (built-in radio, SIM support, Bluetooth version, etc.).

6. Internal memory and data logging

RTK typically provides real-time coordinates, but the ability to record observation data is also important. Many RTK receivers have internal memory to log raw data (e.g., RINEX) for static surveying (long-duration static observations) or post-processing (PPK: Post Processed Kinematic). Internal storage capacity varies from a few MB to several GB or 32 GB and above. If you plan to log large volumes of observation data at high frequency for long periods, choose a model with ample memory.

Some models support USB flash drives or SD cards for easy external copying. Recently, cloud integration features have appeared: positioning data and logged point clouds can be uploaded directly to the cloud for immediate sharing with the office. For example, with our LRTK, acquired coordinate data are automatically stored in a cloud database and can be reviewed from an office PC via the Internet. Choose a receiver with sufficient logging capabilities based on your data management and post-processing needs.

7. Environmental resistance (dustproof/waterproof, operating temperature range)

Construction and surveying sites can be harsh environments. Check the receiver’s environmental resistance. Many surveying instruments indicate ingress protection with international IP ratings. For example, a receiver rated IP67 means that no dust ingress is permitted and it can withstand temporary immersion in water. Major manufacturers’ receivers commonly have dust/water protection around IP65–IP67.

Impact resistance is also important. Rugged units are tested to survive drops from 2 m (6.6 ft) height (mounted on a pole) onto concrete. Also confirm the operating temperature range. Typical ranges are about -20℃ to +60℃, but when working in extreme cold or hot conditions, ensure the specified range covers your use. Battery performance can be affected by temperature, especially in units with internal batteries. Because these are long-term field tools, consider the housing material (magnesium alloy vs. reinforced plastic) and overall robustness, and choose a product with reliable durability.

Translated unit:

• Drop test example: 2 m (6.6 ft) height

8. Battery runtime

Battery life is critical for outdoor surveying equipment. RTK receivers perform continuous high-precision calculations and communications, so power consumption can be high and runtime varies by model. Typical receivers operate continuously for about 5–10 hours on a full charge, though power-efficient designs can run close to 20 hours.

For example, Emlid’s “Reach RS2” claims over 18 hours of RTK operation with its large-capacity battery. Conversely, ultra-compact smartphone-linked devices may only last a few hours due to smaller internal batteries. For long surveying sessions, choose a model with swappable batteries or a dual-battery system that supports hot swapping. Receivers that accept external power allow operation while charging from a power bank or vehicle power. Always check the catalog’s “continuous operation time” to ensure it meets your on-site needs, and consider whether you can carry spare batteries and how long charging takes.

9. Weight and size (portability)

The weight and size of an RTK receiver affect on-site handling. Traditional fixed GNSS receivers integrate antenna, battery, and radio, making them robust but heavy—around 1 kg. For example, many antenna-integrated receivers from major manufacturers weigh about 1.0–1.5 kg. Conversely, recent mobile RTK devices that pair with smartphones or tablets, and wearable GNSS receivers, can weigh only a few hundred grams.

Our LRTK is a representative example: it is far more compact and lightweight than conventional fixed GNSS surveying equipment or total stations. Tasks that formerly required two people carrying equipment into the mountains have been reported to be doable by a single person with LRTK.

A portable receiver reduces burden when accessing narrow paths or survey points only reachable on foot. Note that miniaturization tends to reduce battery capacity and antenna performance, so evaluate the trade-off between required positioning accuracy and portability. If the receiver will be mounted on a vehicle, slightly larger size is acceptable, but for long-distance carry, choose the lightest practical model.

Translated units:

• Typical weight of conventional integrated receivers: about 1 kg

• Manufacturer examples: about 1.0–1.5 kg

10. Software and app integration

Beyond hardware, the supported software environment is critical. To fully utilize an RTK receiver on site, it must integrate with field surveying apps and data processing software. Major manufacturers provide dedicated data controllers (rugged tablets) and software, such as Trimble’s “Access,” Topcon’s “MAGNET Field,” or Leica’s “Captivate,” enabling end-to-end workflows from observation to verification against design drawings.

Newer RTK products from emerging manufacturers increasingly use standard smartphones or tablets for control. For example, Emlid’s receivers are configurable and managed via Android/iOS apps, and our LRTK integrates with a smartphone app to immediately share acquired positions to the cloud for team viewing. Data compatibility with surveying CAD and GIS software (e.g., DXF, LandXML, Shapefile formats) ties directly into on-site workflows. Confirm whether the receiver you plan to buy will smoothly integrate with your current or planned software, including supported data formats and the availability of an SDK. Software usability and extensibility significantly affect actual work efficiency.

Simple surveying achievable with LRTK

With the above checklist, selecting an RTK-capable GNSS receiver that suits your company will greatly streamline on-site positioning tasks. Finally, as a simple surveying solution that even surveying beginners or sites without dedicated survey technicians can use, we introduce our product, LRTK.

LRTK is a compact handheld GNSS receiver that, when paired with a smartphone, enables anyone to easily obtain centimeter-level positioning via RTK. Complex operations are handled by a dedicated app, and tasks from starting positioning to data logging and cloud upload are intuitive, making it accessible for non-specialists. For example, municipal staff inspecting roads or rivers can take geotagged photos, and construction staff can perform quick checks of as-built shapes without large equipment or specialist contractors—LRTK enables immediate, high-precision on-site positioning.

LRTK supports not only network RTK but also Japan’s QZSS-provided free centimeter-class correction service (CLAS). Even in mountain areas without mobile coverage, LRTK can receive correction information directly from satellites and maintain high-precision positioning, enabling surveying independent of terrestrial radio infrastructure. Combining ease of use and reliable accuracy, LRTK is attracting attention as a tool to promote DX (digital transformation) in construction and surveying. Consider LRTK for making on-site positioning easier and smarter.

FAQ

Q1. What is RTK? How does it differ from normal GPS positioning? A1. RTK stands for Real-Time Kinematic and is a technique for obtaining high-precision positions in real time by correcting GNSS positioning errors. Standalone GPS positioning typically has meter-level errors, but RTK uses correction information from a base station to reduce errors to a few centimeters or less. Therefore, RTK is widely used in civil surveying and precise construction management where millimeter-level accuracy is required.

Q2. What equipment and preparations are needed for RTK positioning? A2. RTK positioning fundamentally requires a GNSS receiver for the base station with known precise coordinates and a GNSS receiver for the rover that observes while moving. In addition, you need a communication method to send correction data from the base station to the rover (radio or Internet connection). Recently, it’s common to use national control point services or private correction services to receive corrections over the Internet without installing a dedicated base station. In any case, an RTK-capable high-precision GNSS receiver, communication environment, and a tablet or PC to control them are generally required.

Q3. What should I prioritize when choosing an RTK receiver? A3. It depends on the application, but first clarify “how much accuracy is required” and “what kind of site environment you will use it in.” That will reveal which features you need. For high-precision needs, choose a multi-GNSS, multi-frequency receiver. For mountainous areas without network coverage, a model capable of radio communication is essential. For urban-centered use, a compact network-RTK-capable unit is convenient. In short, compare and evaluate satellite support, frequency bands, communication methods, and positioning accuracy comprehensively and select a model matching your site conditions.

Q4. Is RTK surveying possible in areas with poor radio conditions or forests? A4. In dense forests or urban areas surrounded by tall buildings, satellite signals can be blocked or affected by multipath, making RTK unstable. However, recent GNSS receivers support multiple satellite systems and frequency bands and can capture satellites much better than before. Additionally, augmentation signals from Michibiki (QZSS) and techniques that combine multiple rovers for bridging have appeared to complement positioning under difficult conditions. Still, GNSS positioning is difficult where the sky is completely obscured, so you may need alternative surveying methods or temporarily move to an open area to obtain positions.

Q5. Are qualifications or licenses required to use an RTK receiver? A5. No special qualification is required to operate a GNSS receiver itself, but regulations apply to radio equipment used for communications. If you directly communicate between base and rover using UHF radio in Japan, obtaining a “Land Special Radio Operator” certificate and applying for a radio station license may be necessary (depending on the use of digital simple radio, etc.). Network RTK using mobile networks does not require a radio license. However, public surveying (official surveying for public works) may require national qualifications such as a certified surveyor assistant or higher, so be aware of legal qualification requirements depending on the work.

Q6. Are there RTK surveying machines easy for beginners to use? A6. User-friendly RTK systems for beginners are increasingly available. Receivers that can be intuitively operated from smartphone or tablet apps and devices that automate configuration steps are becoming common. For example, our LRTK enables positioning by following prompts in a dedicated app, and acquired data are stored in the cloud for easy data management. Manufacturers also provide training and manuals, so even first-time RTK users can adopt the technology with confidence.