RTK Positioning Abroad: Communication Environments and Operational Techniques for Ensuring High Accuracy

On overseas surveying and construction sites, RTK (Real Time Kinematic) positioning to ensure centimeter-level high accuracy (half-inch accuracy) has become indispensable for many projects. However, you will often face challenges unique to overseas locations, such as different communication infrastructures and geodetic datums than in Japan, as well as differences in regulations and environmental conditions. To succeed with RTK positioning abroad, thorough advance preparation, appropriate operational techniques, and securing a stable communication environment are essential. This article systematically explains the work process to achieve high-accuracy RTK positioning overseas, from the preparation phase through operation to data verification and recording. It also covers practical points such as considerations for local communication environments, responses to region-specific factors (regulations, satellite visibility, etc.), measures for troubleshooting, team organization, standardization of work procedures, and training of local staff. Finally, the article touches on simple surveying using LRTK with smartphones and small GNSS receivers, introducing the latest solutions that can be applied immediately on site.

Preparation phase: confirming coordinate systems and installing the base station

A fundamental premise that determines RTK positioning accuracy is to correctly understand the local coordinate system and appropriately set the coordinates of control points (known points). Overseas, geodetic datums (reference coordinate systems) vary by country or region; instead of Japan’s JGD2011 (Japan’s geodetic datum), some projects may use WGS-84-based or country-specific datums (e.g., the US NAD83 or Europe’s ETRS89). Therefore, you must confirm the coordinate system required by the project in advance and accurately determine the base station location in that coordinate system.

When installing a base station, it is ideal, if possible, to use local known points (public control points or pre-existing project control) to set the coordinates. If official control point data are not obtainable, methods such as calculating provisional base station coordinates by sufficiently long averaged positioning or, in some cases, PPP (absolute positioning by static observation), then later transforming/correcting to the local coordinate system, can be considered. The important thing is to input the coordinates assigned to the base station without error. For example, a single-digit typo or confusing the geodetic datum/coordinate system can cause a serious error with whole-position offsets on the order of tens of meters. Perform double checks when inputting coordinates and, if necessary, incorporate verification by comparing with other known points.

The base station site selection also affects accuracy. Choose a location where the sky is open and the setup can be made stably. Stay away from tall buildings and metal structures and avoid surroundings that reflect radio waves (sources of multipath). Secure the antenna to a firm tripod or pole so it cannot move during installation. Accurately measure and record the antenna height, and enter it correctly into the receiver and software. Also check the GNSS receiver settings in advance to ensure that the satellite systems and frequency bands you plan to track (GPS/GLONASS/Galileo/BeiDou, etc.) match the local environment.

Preparation-phase checklist example:

• Coordinate system and datum confirmation: Identify the coordinate system to be used for the project (global geodetic datum or local datum) and prepare the required transformation methods

• Collection of control point data: Obtain and verify coordinates for local public control points or known points if available

• Base station coordinate setup: Determine provisional coordinates based on the control points above or sufficient averaged positioning, and input them into the equipment without error (check digit counts and datum)

• Base station antenna installation: Select an open, stable site, secure the antenna, and measure and record the antenna height accurately

• Equipment and power preparation: Configure GNSS receivers and controllers for local settings and prepare batteries and spare power supplies

• Communication means confirmation: At this stage, also check the communication preparations described later (prepare planned radios or SIM cards and perform communication tests)

Operation phase: rover operation and real-time corrections

Once preparation is complete, move to the operational phase using the rover. On the rover side, continuously receiving stable correction information from the base station is the key to achieving high accuracy. When you power on the rover on site, first confirm that the connection with the base station is correctly established. For radio links, ensure the base and rover radios use matching channels and frequency settings; for Internet-based NTRIP connections, confirm that mobile data is available and that you can connect to the correct mount point. Then wait for the RTK status displayed on the rover receiver or controller to become FIX. If FIX is not obtained (showing FLOAT or DGPS), do not start observations, because positioning errors can reach tens of centimeters to over 1 m (3.3 ft) in such states. Always monitor the solution status and begin official measurements only after the status is stably FIX.

During rover observations, enforce the basic practice of keeping the antenna vertical using the pole’s bubble level (prism pole or survey rod). Some rovers have tilt compensation functions, but even then perform calibration in advance and avoid measuring under extreme tilts outside the device’s specification. At each point, stand still for several seconds if possible to stabilize accuracy. If the controller application or receiver has an averaging function, use it—for example, average 3-second or 5-second data to reduce variance from an instantaneous single measurement. Even when collecting many points while moving, ensure at least brief stops for measurement, or use high-frequency logging and extract points later from continuous position data to secure accuracy.

Always keep an eye on the reception of real-time correction data. If the receiver or app displays correction data latency (e.g., “Age of Differential”), check it regularly and ensure fresh data are received within a few seconds. If correction reception is interrupted, the receiver may automatically fall back to single-point mode or a float solution, resulting in loss of positioning accuracy. This can happen if you move out of coverage while traveling or if the base-to-rover baseline becomes too long. If correction data reception is temporarily lost, do not continue observation forcibly; pause and wait for communication recovery or move closer to the base station. If correction resumes but the solution does not immediately return to FIX or is unstable, reinitializing the rover (resetting RTK and reacquiring the solution) can often restore stability more quickly.

Key points to observe during rover operations:

• Always monitor solution status: frequently check whether the rover’s solution is FIX or FLOAT, and treat non-FIX as not meeting high-accuracy requirements

• Keep the antenna vertical: use the pole’s bubble level to avoid tilt-induced errors (same basic rule for tilt-compensated units)

• Allow sufficient observation time at each point: remain stationary for a few seconds per point and use averaging if available to get stable values

• Monitor correction data reception: pay attention to correction latency and disconnections, and suspend measurements or take corrective action if indicators show abnormality

• Check positioning quality indicators: monitor DOP values (HDOP/PDOP) and satellite counts and pause or relocate if values worsen and accuracy is at risk

Verification and recording phase: data checking, inspection, and backup

After on-site observations are completed, perform data verification and organize your records. This phase is crucial to ensure high quality and deliverables that can be relied upon later. First, make confirmation measurements at known points. For example, observe known control points before and after the survey with the rover and verify that results match. Placing the rover at the base station itself and measuring as a “return-to-origin” check is also effective (if the base station coordinates are correct, measuring the same position with the rover should theoretically yield zero difference—verify there is no large offset). Such check measurements help detect systematic errors you may have missed during the work, such as offsets caused by base station coordinate input mistakes.

Next, inspect the data for each point. Plot the measured points in software and compare them to drawings or design values. Check for obviously anomalous coordinates (points that deviate greatly from neighboring points or have unrealistic heights). If an abnormal point is found, it may have been recorded as a float solution or caused by pole movement during measurement. Re-measure or exclude such points from the dataset as necessary. If the receiver recorded per-point RTK status (FIX/FLOAT), consult those logs to identify low-accuracy points.

Verification and correction of height (elevation) data is also important. Many countries use different vertical datums (geoid models), so ellipsoidal heights from GNSS do not directly match local orthometric heights. Measure several local benchmarks or known elevation points and estimate/apply the geoid height difference from the GNSS ellipsoidal heights to align measured heights with the local elevation system. For example, “known benchmark A has an orthometric height of 100.00 m, but the GNSS ellipsoidal height was 98.25 m, so apply a correction of 1.75 m.” Pay attention to vertical as well as horizontal accuracy and apply necessary corrections.

After verification, proceed to data storage and organization. Immediately create backups of electronic data. Export point coordinates from the controller or receiver as CSV or text and copy them to cloud storage or a laptop. If possible, record and save GNSS raw data (RINEX, etc.) from both the base and rover; this is useful if you need to reprocess data later (e.g., with PPK). For critical observations, consider combining base station static observation data with reference data from the International GNSS Service (IGS) for PPP processing to obtain an independent solution and compare it with RTK results.

When organizing records, prepare deliverables as survey result files and reports. Include each point’s coordinates (both latitude/longitude and local coordinates if needed), observation date and time, personnel, base station ID and coordinates, RTK FIX/Float status, estimated errors, and so on. A survey diary-like note is helpful: record communication trouble periods, weather interruptions, and other events that affect data reliability. Photos documenting base station setup and point locations are recommended; include point numbers in the file names.

Finally, prepare the data in the required format for submission. Overseas projects often have specified submission standards, so confirm whether outputs meet conditions such as “output in a particular zone of a plane rectangular coordinate system” or “heights in the local datum at x m units.” If unclear, consult local surveyors or the client and perform any necessary conversions or formatting. Only with appropriate verification and record keeping can RTK results be considered trustworthy and ready for use.

Summary of verification and recording points:

• Accuracy confirmation at known points: re-measure known benchmarks after surveying and verify horizontal and vertical alignment

• Anomaly detection in observed data: compare measured point layout to drawings and remeasure if obvious deviations occur

• Vertical datum adjustments: convert GNSS ellipsoidal heights to the local elevation system as needed to ensure height consistency

• Multiple backups: store point and GNSS raw data on multiple media to mitigate data loss risk

• Base station information records: log base station coordinate settings, datum, antenna height, operating times, and reference control points for future inquiries

Considerations and stabilization of the communication environment

Securing a communication environment for RTK positioning overseas requires more careful preparation and consideration than in Japan. First, if you plan to use Internet-based corrections (NTRIP), investigate mobile data coverage and quality in the region in advance. Urban areas are often fine, but rural or developing regions can be unstable. Prepare SIM cards for local carriers and test signal strength around the site. If multiple mobile carriers operate locally, carry SIMs for backup so you can use the stronger one. For large work areas, check carrier coverage maps beforehand to identify weak-signal zones. When using a smartphone or mobile router on site, reduce communication loss by placing the device in high, open locations or using an external-antenna router.

If you plan to use your own radio link between base and rover, pay close attention to local radio regulations. Frequencies commonly used for RTK radios in Japan (e.g., 351 MHz band digital simple radios or low-power UHF) may be restricted or require licenses overseas. Check whether the radio equipment you plan to use is legal in the target country and obtain any required permissions or licenses from local authorities beforehand. If licensing is difficult, consider using internationally license-free bands available in many countries (for example, some LoRa frequencies around 900 MHz) as alternatives.

When using radio links, ensure sufficient range and stability. Install the base station antenna as high as possible to reduce obstruction. High-power radios can reach distances of several kilometers in line-of-sight, but in mountainous terrain or urban areas with building shadowing, you may need repeaters or additional base stations. Before beginning full operations, perform a communication test run with the rover to confirm the coverage extent of correction signals.

Also be mindful of electromagnetic interference from the surroundings. High-voltage power lines and communication antennas can produce EM noise that affects GNSS reception. Construction sites often contain various radio sources—remote controls for heavy machinery, other teams’ radios, workers’ Wi-Fi routers, etc. Change radio channels or move antennas away from interference sources as needed to minimize noise. Some GNSS receivers provide notch filters to suppress interference at particular frequencies—use such features according to local conditions.

Redundancy in communication methods is an effective risk hedge. For example, use mobile NTRIP communications as the primary method but also have a direct radio link as a backup, or assign different mobile carriers to key personnel so they can share hotspots if needed. If real-time communication cannot be guaranteed, log raw data on the rover and perform PPK processing later in the office. Ideally, prepare to prevent data loss even when real-time RTK is unavailable.

Key points to stabilize communications:

• Pre-check mobile communications: prepare local SIMs and perform area checks; have backup lines if necessary

• Regulatory compliance for radio use: research local frequency regulations and licensing requirements, and acquire permissions if needed

• Antenna placement: set base station antennas in high positions and have rovers work where line-of-sight is possible to enhance range and stability

• Measures against RF interference: avoid strong-field noise sources and change channels or relocate antennas during temporary interference

• Redundant communication options: prepare both Internet and radio links and multiple SIMs so one method can cover failures in the other

• Plan B for worst-case: if real-time RTK fails, ensure data logging on the rover for later post-processing (PPK)

Adapting to regional characteristics (regulations, satellite visibility, etc.)

When operating RTK positioning overseas, you must adapt to country- or region-specific circumstances. Begin by considering local regulations. Laws and rules regarding surveying and geolocation vary by country; some require government authorization or involvement of certified local surveyors, or impose restrictions on exporting high-accuracy positioning data. Performing precise surveying without permission under the assumption that it’s the same as in Japan can lead to trouble, so investigate local surveying laws and comply accordingly. If possible, partner with a local surveying firm or consultant to assist with necessary procedures and permits. Radio regulation issues mentioned earlier, and regulations related to drone operations (aviation rules), are part of the compliance checklist—identify all applicable rules.

Also consider differences in GNSS satellite visibility and positioning environments. Positioning accuracy heavily depends on the number and geometry of satellites visible above the horizon. In Japan, the QZSS (Michibiki) quasi-zenith satellites offer advantages, but outside Japan you may not be able to use QZSS, or it may appear at low elevation. Instead, you can often benefit from other GNSS like Europe’s Galileo or China’s BeiDou, which may be plentiful in some regions. Use multi-GNSS-capable receivers and enable all satellite systems available locally. For example, enable Galileo in Europe and BeiDou (and QZSS where available) in the Asia-Pacific region. In the Southern Hemisphere, placing the base station where the northern sky is open improves GPS reception; hemisphere differences in satellite geometry should be anticipated. Running a visible-satellite simulation for the local latitude/longitude using GNSS planning software can be useful for predicting satellite availability.

Natural environmental factors in each region also affect planning. Near the equator, intense daytime sun and sudden evening squalls are common; high temperature and humidity accelerate equipment heating and battery drain, so manage human and equipment conditions by using shade and resting frequently. In cold or high-altitude areas, battery performance degrades and manual dexterity can suffer, so provide cold-weather measures and spare batteries. In mountainous or jungle terrain with poor sky view, RTK may not function reliably; in such cases, consider moving the base station to an open area and using traverse surveys from that point to measure detailed areas—i.e., combine RTK with conventional methods. Avoid the rigid assumption that everything must be done solely by RTK; adapt surveying techniques to the situation for success.

Account for local infrastructure conditions as well. In developed urban areas, government or private RTK correction services (CORS networks or VRS services) may be available and can be used via subscription without setting up your own base station. Research local services and consider using them when available. Conversely, in underdeveloped regions, procuring equipment or spare parts locally may be difficult; bring multiple spares from Japan or arrange international shipping and prepare contingency plans for equipment failures.

Finally, coordinate with local workers and other construction activities. Cultural and language differences can lead to misunderstandings; for example, heavy equipment operators might start earthworks right next to your survey area unless you coordinate. Assign a local coordinator to manage site communication—through local staff or interpreters—so you can clearly communicate requests like “We will perform high-precision positioning here now, please pause heavy equipment.” Ensuring safe and stable working conditions is an important role for the team leader.

Troubleshooting strategies

No matter how thorough the preparation, unexpected problems can occur on site. The important thing is to anticipate likely trouble patterns and respond calmly. Here are common problems encountered during RTK operations and ways to address them.

• Correction data not received: If corrections from the base station stop reaching the rover, high-accuracy positioning cannot be maintained. Causes include loose radio wiring, wrong radio channels, mobile network outages or data caps, and NTRIP configuration errors. Countermeasures: Check communication indicators and quickly isolate the cause. For radio links, check antenna connections and power and move if obstacles block signals. For Internet connections, reboot the phone/router, move to an area with better signal, and check remaining data quota. If recovery fails, suspend surveying until communication returns, move closer to the base, or switch to another mount point for correction services. Preemptive redundancy in communication routes helps—if one path fails, you can switch to the other.

• Rover never reaches FIX (no high accuracy): If the rover remains in float and never attains FIX, it may be due to poor satellite geometry, heavy multipath from surrounding structures, or an excessively long baseline. Countermeasures: Check satellite counts and DOP values; if satellites are few or DOP is high, wait for a better time or move to a location with a clearer sky. If baseline length is the issue, relocate the base station closer to the rover or switch to nearby correction sources (public control or VRS). In high-multipath environments, raise the antenna, add a ground plane, or increase elevation mask to exclude low-elevation satellites. Rebooting the receiver can sometimes help if device firmware has become unstable. Importantly, avoid wasting time insisting on a FIX in hopeless conditions—if FIX cannot be obtained after a reasonable wait, consider withdrawing and reattempting under different conditions.

• Systematic offsets in resulting positions: After processing, if the dataset shows a uniform offset from expected positions, the cause is usually incorrect base station coordinates or a datum mismatch (absolute accuracy error). For example, entering local coordinates where latitude/longitude were required or selecting the wrong zone in a projected coordinate system can produce such errors. Countermeasures: Compare results to control points to determine any consistent offset in north/east/up. If uniform, you can apply a translation to all data in post-processing by calculating the offset from control points and applying it, provided there is no rotation or scale error. If the problem is using the wrong datum, more complex coordinate transformations may be needed, and the most reliable remedy is to reobserve the base station with the correct coordinate settings. To prevent recurrence, strengthen double-check procedures during base station setup.

• Equipment failure / power loss: If base or rover equipment fails or batteries deplete, have spares on hand as a preventive measure: spare GNSS units and spare batteries or power banks. When trouble occurs, isolate the cause calmly—determine whether the rover is off due to power loss or frozen software—and attempt power cycling or device reset. If the base station loses power, swap to a spare battery immediately. Consider vehicle power via a cigarette lighter or generator to extend run times. If recovery is impossible on site, stop the day’s work and bring equipment back for repair. Do not continue collecting data with malfunctioning gear; it is better to pause than to produce unreliable data.

• Human errors: Mistakes are inevitable—examples include holding the rover pole tilted, entering the wrong antenna height, misnaming points, or failing to save records. Countermeasures: Although eliminating human error entirely is difficult, minimize it with double-checks and adherence to standard procedures. Have another person visually confirm the pole bubble, read back antenna height entries aloud, and immediately copy important files to a laptop after saving. If an error is discovered, recover in the field if possible—for example, correct antenna height input and recalculate or reobserve affected points. Treat human errors as learning opportunities and implement preventative measures to avoid repetition.

By organizing likely problems and responses in advance, you can respond calmly to on-site contingencies. The motto for troubleshooting is “don’t panic, don’t give up, and be resourceful.” Unexpected events are more likely overseas than in Japan, but with calm handling most issues can be overcome.

Building the team and assigning roles

To execute RTK positioning overseas smoothly, establish a robust team structure and clearly define each member’s roles. Communication issues due to language and cultural differences can lead directly to mistakes, so the team leader should foster a shared priority of “accuracy first” among all members, whether they are Japanese or local staff.

Typically, divide core roles into a base station operator and a rover operator. The base station operator sets up the base on a control point in the morning and monitors its stable operation, handling battery checks and monitoring correction data distribution. Rover operators (one or more) traverse the site, observe points per the drawings or plans, and handle marking and photography as needed. Ideally, base station and other support staff provide communication and equipment backup to allow rover operators to focus on surveying.

When possible, include a data management person to receive rover data in real time on a laptop or tablet and perform quality checks from the office side. Having a real-time QA (quality assurance) person can rapidly identify low-accuracy points (“point A is Float—please remeasure”) and improve data quality on the fly. In large projects, a real-time QA role is particularly effective.

Information sharing within the team is essential. Hold a morning meeting to review the day’s plan and precautions, and a debrief to share progress and lessons learned. Overcome language barriers via interpreters so everyone understands the day’s tasks. Teach practical site phrases and gestures such as “Fix OK?” or “Stop!” in a common set of keywords. For safety, avoid lone working—operate at least in pairs—and ensure staff always have radios or phones when dispersed.

Also invest in training. Relying on a single expert leaves the team vulnerable if that person is unavailable. For long-term overseas projects, train multiple staff members (including locals) in RTK procedures. Japanese veterans can mentor local staff until they can handle base setup and surveys independently. This creates flexibility for recovery in incidents and raises team morale.

Typical team roles:

• Site manager (team leader): plans overall survey work, manages progress, coordinates with local parties, and oversees safety and team environment

• Base station operator (fixed station operator): installs and removes base station, sets base coordinates, and monitors equipment and communications

• Rover operator (mobile operator): operates the rover, observes and records points, moves between points, and marks locations accurately

• Data management (quality checker): monitors measurement data in real time, identifies issues, and instructs remeasurement as needed; manages data organization

• Technical support (IT/GNSS expert): provides advanced technical support such as GNSS processing and system troubleshooting; role may be combined with the leader in small teams

You may not be able to fill all roles with separate individuals depending on project size, but the important thing is to make responsibilities clear. This clarifies accountability and reduces coordination errors. Overseas, misunderstandings are common; assign ToDo lists and checklists per role and have team members mutually confirm tasks.

Standardizing work procedures and guidelines

Standardizing procedures improves quality and efficiency and reduces human error. In overseas projects, with varying staff turnover and skill levels, establishing standardized procedures that ensure consistent outputs regardless of who performs the task is essential. Following standardized guidelines reduces the risk of omission by less experienced staff and provides a checklist for veterans.

The first step in standardization is to document the workflow step by step and specify required tasks for each step. For example, for “base station setup” list steps such as (1) confirm the known point → (2) install antenna → (3) input coordinates → (4) test communications → (5) record antenna height, and annotate precautions for each step (e.g., “coordinate input double-checked by two people” and “measure antenna height to the mm level (0.04 in)”). Presenting tasks in a checklist format helps prevent missed steps under pressure.

Base station setup quick checklist example:

• Reconfirm control point coordinates and datum and ensure receiver settings match

• Measure and accurately input antenna height (note vertical vs slant distance and units)

• Secure antenna (use weights or guy lines for wind protection as needed)

• Confirm correction data transmission has started (radio LED blinking or NTRIP distribution status)

• Photograph the base station location and equipment with dates recorded

Similarly, a rover observation procedure should include explicit actions like “confirm FIX at each point,” “check pole bubble for verticality,” and “stand still for 5 seconds.” A data processing procedure should list “control point checks,” “apply coordinate transformations,” and “backup saves.” Include fields for responsible person and date on each checklist so you can trace who performed and verified each step.

Prepare these manuals as company-standard documentation to bring to the site. Use illustrations and photos to overcome language barriers—show “good/bad” antenna setups, example screens for FIX vs FLOAT, and so on. Update manuals as new lessons and trouble cases arise to accumulate knowledge over time.

To ensure guidelines are followed on site, integrate them into daily routines: review checklists at morning briefs, require signatures or stamps when tasks are completed, and have supervisors model adherence to the guidelines. This builds a culture where members expect to be checked and thus helps the procedures take root.

Finally, adopt continuous improvement: collect feedback from the field about inefficient steps or missing checks and promptly update manuals. With standardized guidelines and a PDCA approach, overseas RTK operations can achieve reproducible, high-quality results.

Main items to standardize:

• Base station setup procedures: site selection through coordinate input and start of correction distribution

• Rover observation procedures: point observation methods and required checks before/after measurement

• Communication troubleshooting flows: step-by-step checks and recovery procedures specifying who does what

• Data management procedures: post-survey verification, backups, transformations, file naming, and reporting formats

• Safety management rules: safe working practices including paired working, traffic control, and restricted access to hazardous areas

Training local staff and transferring skills

For overseas projects, invest in training local staff and transferring expertise from Japan. Educating not only dispatched staff but also locally hired technicians and workers in proper RTK operations raises team capability and improves efficiency. Leaving technical knowledge locally also contributes to the host country and creates long-term benefits.

Begin education with basic knowledge sharing: teach RTK-GNSS principles, necessary equipment, basic operation flows, and key precautions in classroom sessions. Use plain English or the local language where possible and avoid jargon; supplement explanations with diagrams, illustrations, and actual equipment. For example, show how satellite signals travel and demonstrate FIX vs FLOAT on a real receiver screen. Provide manuals in the local language or annotate keywords in the local language to aid understanding.

Hands-on OJT (on-the-job training) is essential. Pair experienced staff with local trainees when setting up the base and performing rover surveys. Demonstrate tasks step by step, then have trainees perform them under supervision. During observations, instruct in real time (“It’s FLOAT now, wait”; “Now it’s FIX, record this point”) to reinforce learning. Allow trainees to make mistakes so they learn from consequences—intentionally causing a tilt to demonstrate its effect on positioning helps trainees appreciate the importance of correct practice.

Explain underlying principles as well as procedures—don’t just have trainees memorize steps. Understanding why you must keep an antenna vertical or why loss of correction degrades accuracy fosters problem-solving skills. For example, if a trainee asks why tall buildings are bad for accuracy, explain multipath simply so they grasp the rationale and can adapt in unfamiliar situations.

As trainees attain competence, gradually delegate authority. Initially, Japanese staff lead operations; over time transfer routine tasks such as daily base setup to local staff while Japanese staff performs final coordinate checks. The aim is to have local teams perform most field operations autonomously while the Japanese side provides oversight. This fosters motivation and builds team resilience.

Follow up continuously. Don’t assume a single training session is enough—periodically test understanding, observe fieldwork for errors, and provide refresher training or mentoring for new personnel. Develop a local leader to centralize knowledge transfer and broaden the pool of skilled staff.

By training local staff and transferring techniques, RTK positioning projects overseas become sustainable and embedded in local capability rather than one-off missions. This is a valuable asset for Japanese companies expanding internationally.

Key points for training local staff:

• Consider language and culture: avoid technical jargon, use local language or clear diagrams to aid understanding

• Emphasize practice: combine classroom instruction with field OJT and experiential learning

• Explain underlying principles: teach the “why” behind procedures to develop adaptive problem-solving skills

• Gradually delegate responsibilities: let local team members take on more tasks as skills increase

• Ensure retention and follow-up: conduct regular reviews and continued training so skills are maintained and passed on

Conclusion: LRTK simple surveying using smartphones + small GNSS receivers

So far, we have discussed various preparation and operational techniques to ensure high accuracy with RTK positioning overseas. Finally, let’s look at a simple surveying solution that leverages the latest technologies. Combining smartphones with ultra-compact GNSS receivers for RTK positioning—known as LRTK—has recently attracted attention as a way to make high-accuracy field surveying much more accessible. LRTK is a new approach that makes conventional RTK-GNSS lighter and easier to use.

For example, attaching a dedicated small RTK-capable GNSS module to an iPhone or Android smartphone turns the phone into a centimeter-level surveying device. With pocket-sized units weighing only a few hundred grams and built-in batteries, site supervisors and workers can each carry one per person and take it out for quick measurements. With a dedicated app, just pressing a button can obtain high-precision coordinates in real time and record and share them immediately.

Traditional RTK surveying required multiple devices—two GNSS units (base and rover), a data collector, radio modems, and physical setup. LRTK consolidates these functions into a smartphone-integrated device. Some products are smartphone-case-style receivers that, when attached, allow reception of GPS/GLONASS as well as Galileo and BeiDou for a multi-GNSS environment. Correction data can be received via an embedded SIM or the phone’s network, and NTRIP is supported so RTK can be completed standalone. The initialization performance can achieve FIX within seconds, and short-time averaging functions can deliver high-accuracy positioning on the order of about 8 mm (0.31 in) to 1 cm (0.4 in). Devices are designed so that even untrained people can operate by following on-screen prompts.

LRTK simple surveying brings enormous benefits to the field. Tasks that previously required calling in a survey team with total stations or an RTK set—such as quick point checks—can now be done by the on-site person in charge. Stakeout tasks can guide users to target positions via smartphone screen instructions, enabling accurate marking by non-specialists. Measured points can be uploaded to the cloud immediately, allowing real-time information sharing and discussion with supervisors or design staff without returning to the office. Integration with AR technology lets you visualize measured points and photos on site, greatly streamlining consensus building and as-built inspections.

As LRTK smartphone-based simple surveying becomes more widespread, the barrier to high-accuracy positioning on overseas sites will be greatly lowered. The rigorous procedures and cautions described in this article remain important foundations, but new tools increasingly package those complexities into user-friendly systems that make it possible for non-experts to avoid mistakes. For example, apps may automatically handle datum differences or monitor correction data and issue alerts. Improved on-site responsiveness enables quick adaptation to design changes and inspection tasks, boosting overall productivity.

For Japanese firms applying RTK positioning overseas, the ideal approach is to master both traditional precise surveying techniques and the latest digital solutions. The former ensures reliable, principle-based operations, while the latter enhances field capability. Consider adopting new technologies such as smartphone + small GNSS LRTK in your projects to make high-accuracy positioning an everyday, on-demand tool on overseas sites. With solid preparation, sound operational practices, and innovative tools, RTK positioning abroad can become an even more powerful ally.