RTK-GNSS Comparison Reveals: LRTK Smartphone Surveying Enables Manpower and Labor Savings

Table of Contents

• Introduction: Demand and Challenges for RTK-GNSS, and the Background of LRTK's Emergence

• What is RTK-GNSS?

• What is Smartphone RTK?

• Comparison of RTK-GNSS Equipment and LRTK: Functions / Accuracy / Cost / Training / Maintenance

• How LRTK Smartphone Use Enables Manpower and Labor Savings

• Use-Case Comparisons: As-Built Management, Stake Placement, Volume Calculation, AR Guidance

• Strengths of Cloud Integration and Real-Time Sharing

• Comparison of Training Costs and Risks of Skill Concentration, and Ease of Adoption

• LRTK Adoption Cases and Voices from the Field (Manpower Reduction, Safety, Reduced Implementation Costs)

• Conclusion: Encouraging the Adoption of Simplified Surveying with LRTK

• FAQ (Frequently Asked Questions)

Introduction: Demand and Challenges for RTK-GNSS, and the Background of LRTK's Emergence

In recent years, the use of GNSS (satellite positioning) on construction and surveying sites has advanced, and RTK-GNSS surveying—which can measure high-precision positions in real time—has attracted attention. Traditionally, surveying relied on large optical instruments like total stations or dedicated GNSS receivers; while they provide high precision, they also bring challenges such as heavy equipment that often requires work in pairs. These precision instruments also require regular calibration and maintenance, resulting in significant costs for acquisition and upkeep. On the other hand, consumer handheld GPS units or smartphone-integrated GPS typically have positioning errors on the order of several meters (about 5–10 m), making them unsuitable for tasks requiring centimeter-level accuracy, such as map creation or stake placement. Therefore, high-precision surveying has required dedicated RTK-capable GNSS equipment, reception of correction information (error-correction data) from a base station or over the internet, and considerable expense and specialized knowledge.

Against this backdrop, a demand grew for a new method that would allow high-precision positioning easily. Chronic labor shortages on sites and the aging and decline of skilled surveyors have made new technologies that enable manpower and labor savings increasingly sought after. Emerging in this context is the smartphone-based LRTK smartphone RTK solution. This article presents a concrete comparison between traditional RTK-GNSS surveying equipment and smartphone RTK (LRTK), highlighting the manpower and labor savings, cost efficiency, mobility, and training advantages LRTK brings to the field.

What is RTK-GNSS?

RTK-GNSS (Real-Time Kinematic GNSS) is a surveying technique that corrects GNSS satellite positioning errors in real time to determine coordinates with centimeter-level accuracy. A single GNSS receiver alone typically experiences errors of several meters due to atmospheric and satellite orbit errors, but the RTK method places an additional receiver as a base station (reference point) and computes the relative error between that base point and the moving receiver (rover) to correct the rover’s positioning results. Correction data are sent from the base to the rover via radio or cellular networks, and the rover computes the result to obtain high-precision positions in real time. RTK surveying generally achieves horizontal accuracy on the order of 2–3 cm and vertical accuracy of about 3–5 cm, meeting the precision requirements of surveying sites.

Conventional RTK-GNSS surveying systems consist of a dedicated high-precision GNSS antenna and receiver, a control controller, and sometimes communication modems or radios for data links. Survey work typically begins by placing the base station at a known point, then moving the rover to the points to be measured. High-precision RTK positioning requires a clear view of the sky to capture satellites adequately; immediately after starting positioning, the solution may initially be in a larger-error state called a Float solution, and within several tens of seconds it converges to a stable Fix solution (integer-fixed solution). Once in Fix, centimeter-level coordinates can be obtained at each point. Although conventional GNSS surveying equipment is robust and accurate, a full system is expensive to operate and requires specialized knowledge, so dedicated surveyors often handle the operation.

What is Smartphone RTK?

Smartphone RTK is a general term for techniques and solutions that perform RTK-GNSS positioning using a smartphone. Recent smartphones include high-performance GNSS chips, and some models now support acquisition of raw GNSS data and multi-frequency reception required for RTK. Thanks to these advances, centimeter-class positioning with a smartphone is becoming feasible even without dedicated equipment. However, the antenna performance and reception environment of a standalone smartphone impose limits on achievable accuracy, so a practical smartphone RTK setup often pairs the phone with a small external high-precision antenna/receiver device.

From this idea emerged the smartphone RTK solution centered on the LRTK Phone. By attaching a compact RTK-GNSS receiver device to a smartphone (currently mainly iPhones), and linking a dedicated app with cloud services, it becomes possible to achieve centimeter-level positioning and a variety of measurement functions comparable to traditional surveying equipment using just a smartphone. Utilizing the phone’s camera and LiDAR sensor, the solution goes beyond simple positioning to offer 3D scanning (point cloud measurement), stake placement guidance, and on-site AR visualization. In other words, a “smartphone-as-surveying-instrument” era has arrived. Tasks that once required carrying heavy equipment can now be performed with a pocketable smartphone plus a small device, allowing each field technician to carry their own high-precision surveying tool and take measurements whenever needed.

*By attaching a small LRTK device to a smartphone, RTK positioning comparable to traditional equipment becomes possible*

Comparison of RTK-GNSS Equipment and LRTK: Functions / Accuracy / Cost / Training / Maintenance

Let’s compare traditional RTK-GNSS surveying equipment and smartphone RTK solutions (LRTK) across several perspectives.

• Functionality: Conventional equipment is specialized for surveying functions such as high-precision single-point coordinate measurement and geodetic transformations. LRTK offers equivalent high-precision positioning plus a wide range of features leveraging smartphone cameras and sensors—photo capture, point cloud scanning, and AR display. For example, LRTK can record coordinates and orientation with site photos during positioning, or capture 3D terrain models while walking, enabling tasks that previously required multiple devices or steps to be completed with a single smartphone. Cloud integration provides data sharing and analysis functions, making LRTK a platform-like, multifunctional tool rather than only a positioning device.

• Accuracy: Both high-quality dedicated GNSS equipment and LRTK can achieve centimeter-level horizontal and vertical accuracy when an RTK-Fix solution is obtained. While conventional equipment is well-known for its precision and stability, LRTK tests have shown positioning differences versus dedicated equipment of 5 mm or less, indicating comparable accuracy. In open environments, LRTK can acquire Fix in about 20 seconds and maintain centimeter accuracy while moving. Moreover, smartphone-based continuous surface measurement can yield comprehensive, gap-free data collection, which can be advantageous for overall precision and quality control.

• Cost: Dedicated RTK-GNSS equipment entails high initial costs, and if a base station is set up privately, the full set is required. Operationally, communication service contracts and maintenance costs are added. In contrast, LRTK leverages users’ existing smartphones and requires only a small device and app subscription, dramatically reducing initial costs. You can use network RTK services provided by national agencies or CLAS satellite augmentation (discussed later) without preparing your own base station, keeping additional expenses low. Instead of procuring multiple expensive dedicated units, organizations can enable a one-device-per-person system by attaching devices to each worker’s smartphone, and the ability to measure whenever needed improves operational efficiency and cost performance.

• Training (learning curve): Traditional surveying equipment is specialized and requires time for trainees to become proficient, often concentrating work in a few veteran staff and requiring long training periods for newcomers. LRTK’s smartphone app offers intuitive Japanese UI and operations that nearly anyone can use without confusion. For basic positioning, just a few minutes of instruction suffices to start working on site. Non-experts can achieve high-precision results by following the app’s guidance, allowing survey novices to become effective quickly. Training costs and time are dramatically reduced, lowering internal barriers to workforce development.

• Maintenance and operation: Conventional equipment needs periodic inspections, calibration adjustments, and software updates, and repairs may require manufacturer support. LRTK’s main components are a small device and a smartphone, with software updates handled easily via the app. Integrated devices with internal batteries and antennas reduce cabling and field setup issues. If a smartphone fails, another phone can quickly take over, offering flexibility. The simpler system leads to lower maintenance costs and easier routine checks.

How LRTK Smartphone Use Enables Manpower and Labor Savings

How does the LRTK smartphone surveying solution enable manpower and labor savings on site? The mechanism can be explained with several points.

First, LRTK makes it easier to complete high-precision surveying as a single-person task. Traditionally, surveying often required teams of two or more, but by attaching LRTK to a smartphone and mounting it on a monopod, one person can perform reference point surveys and stake placement. Using a dedicated monopod allows height offsets (height from the ground to the instrument) to be preset in the app, and the procedure is simplified to leveling the bubble and taking the measurement. If stake placement that formerly required two people can be done by one, the second person can be reassigned, creating workforce flexibility. The need to send two people into hazardous areas also decreases, improving worker safety.

Next, reduction in work time and effort is a major labor-saving benefit. LRTK initializes positioning quickly, and once Fix is obtained, many points can be measured continuously while walking, enabling the capture of numerous survey points across a wide area. Where the old workflow required setting up a tripod and measuring each point individually, with a smartphone you can walk while collecting surface data. For example, in large site elevation surveys where only a few representative points were previously measured to infer terrain, smartphone RTK can capture point clouds for the entire site and compute cut-and-fill volumes on the spot. Measurement, calculation, and recording can be completed in a single pass, eliminating follow-up surveys and office-based calculations and significantly shortening total work time.

Additionally, real-time sharing and automatic cloud saving of survey data reduce intermediate tasks between field and office. Coordinates and point clouds collected by the LRTK app can be synced to the cloud with one tap, enabling all stakeholders to view and use the data immediately. There’s no need to bring data back via USB or transcribe handwritten notes, achieving administrative labor savings through digitalization. If analysis and drawing generation are completed in the cloud, handing off to specialist departments is minimized, and the overall reporting workflow becomes more efficient.

Thus, by introducing LRTK to the site, a system is created to “conduct surveying with fewer people, in less time, without waste, and more safely.” This is an effective countermeasure to chronic labor shortages and is notable as part of work-style reform efforts.

Use-Case Comparisons: As-Built Management, Stake Placement, Volume Calculation, AR Guidance

Here are comparisons of how LRTK smartphone surveying proves effective in representative field tasks versus traditional methods.

• As-Built Management (post-construction shape measurement): Traditionally, when checking ground elevations after paving or site formation, only limited points were measured with a level to estimate thickness, or staff would measure fragmented cross-sections with tapes or survey equipment. With LRTK, you can perform a point-cloud scan of the entire construction area and record the as-built surface comprehensively. Sites that introduced LRTK for as-built management reported that measuring ground elevations before and after paving across the surface to check construction thickness greatly improved efficiency in verifying finish quality. Areas that were once sampled are now fully scanned by walking the site with a smartphone, enabling complete quality control without omissions. Extracting arbitrary cross-sections from point cloud data and color-coding deviations from the design model in the cloud can be done with a single click, enabling immediate on-site verification to decide whether rework is necessary.

• Stake Placement and Reference Point Establishment: On construction sites, stake placement and setting reference points previously required inputting coordinates into surveying instruments and searching for target positions by sighting through instruments. Optical methods often required two people to set a prism and reference a point, and even GNSS staking relied on controller readouts or audio guidance, requiring skilled operators. LRTK’s coordinate navigation (guidance) function displays arrows and distance to pre-set target coordinates on the smartphone screen in real time. By following this display and walking, users can reach the target point, enabling anyone—not only specialists—to pinpoint stake locations to centimeter precision. Users have reported that “walking according to the smartphone guidance led me directly to the stake position” and “a single person could measure without getting lost,” confirming that stake placement can be performed easily by anyone.

• Volume Calculation (cut and fill measurement): LRTK excels at earthwork volume management. Traditionally, pre- and post-construction surveys were performed and point clouds compared in the office to compute volume differences, sometimes requiring CAD skills and taking days to get results. With LRTK, scan the site before and after work with a smartphone and have the cloud automatically compare point clouds to compute volume differences on the spot. One site reported that by measuring cross-sections and calculating differential volumes the same day, operators could relay instructions to heavy-equipment operators within the day. This enabled early correction of over- or under-filling, improving quantity control accuracy and shortening schedules.

• AR Guidance and Visualization of Subsurface Utilities: LRTK is powerful for construction support using AR and for managing buried utilities. Traditionally, confirming the location of underground utilities required marking and careful excavation, and determining their precise positions after backfilling was difficult. LRTK stores captured utility point clouds and design 3D models in the cloud with absolute coordinates, allowing AR visualization on a smartphone. For example, you can visualize the route of pipes buried underground through the phone, so the positions of buried utilities are never lost. Without leaving markers, AR enables precise relocation during re-excavation, preventing mistakes and improving safety. AR-based construction guidance is also convenient: loading design models into the app and projecting them into real space can display slope lines for earthworks to prevent over-cutting or place a model at a sign installation point to check the finished look. Tasks that once relied on skilled judgment or repeated layout are now intuitively guided and verified by AR, reducing errors and improving efficiency.

Strengths of Cloud Integration and Real-Time Sharing

One of LRTK’s major strengths is real-time data sharing via cloud integration. With hardware (device), app, and cloud service functioning as one, survey data utilization and stakeholder information sharing are seamless. After positioning or point-cloud scanning on site, data can be synced to the cloud with one tap from the app. Uploaded positioning data is immediately plotted on the cloud map, and office staff or clients can view site results in real time with just a browser login—no specialized software required.

On the cloud, captured coordinates and point clouds can be displayed in 2D map or 3D view, and analyses such as distance measurement, area, and volume calculations can be performed on the spot. Extracting cross-sections from large point clouds or overlaying design data to color-code deviations are done in the cloud with a single button. Tasks that previously required returning to the office and processing on high-performance PCs with specialized software can now be carried out directly online from the field. If necessary, external share links to cloud data can be issued so contractors or clients without licenses or specialized viewers can inspect survey results on their PCs or tablets with an internet connection. Not needing specialized software or high-spec PCs is a big advantage for recipients.

Real-time sharing also changes communication workflows. For example, if additional measurements are needed on site, the office can send new target point coordinates via the cloud, which will immediately appear on the field smartphone map and be available for guidance. Conversely, the office can rapidly create drawings or reports based on high-precision photos or point clouds uploaded by the field. In an environment where data is shared instantly, assembly and review processes that once took days are greatly shortened, dramatically improving overall operational efficiency.

Furthermore, cloud-and-app integration enables fine-grained responses to site needs. The app can automatically assign sequential IDs and arbitrary notes to measured points, digitizing notes in place instead of writing them on paper field books and preventing human errors like illegible handwriting or transcription mistakes. Photos are tagged with date, orientation, and coordinates, simplifying photo logs and evidence of locations. Uploading design drawings or BIM models to the cloud allows the app to align coordinate systems and display the design model in AR for on-site comparison with as-built conditions. Being able to compare as-built with design on the spot enables immediate correction decisions and contributes to real-time quality control.

Thus LRTK is more than a precise surveying instrument: through cloud and app integration it becomes a platform that smartens and streamlines the entire workflow. The ability to perform data capture, sharing, analysis, and reporting in a single flow represents the next-generation “smart surveying” style.

Comparison of Training Costs and Risks of Skill Concentration, and Ease of Adoption

When introducing new technology to field operations, training costs and the risk of skill concentration are common barriers. Traditional surveying equipment requires specialized operation and experience, often resulting in a limited number of “people who can use it” within an organization; if they are absent, surveying can halt. New employee training also consumes time and money, and surveying tends to be left to specialized departments while field staff avoid it, hindering in-house skill development.

LRTK smartphone surveying significantly lowers these barriers. The intuitive smartphone app interface eliminates the need for deep technical knowledge, enabling use from day one without special training. There are case reports of users being able to put the LRTK device in a pouch, head to the site, and capture point clouds with one hand after about five minutes of explanation. Whether new or veteran staff, anyone comfortable with smartphones can adopt it smoothly. Once a few people in-house learn the workflow, they can quickly spread the skills to others, reducing reliance on a single expert and creating an organizational structure that does not depend heavily on specific individuals. The risk of skill concentration decreases, and even with personnel changes or departures the organization retains surveying capabilities more readily.

Regarding ease of adoption, low cost and technical barriers are significant advantages. As noted, initial cost is much lower than dedicated equipment, making a small-scale trial start feasible. You can experience the benefits and then scale up incrementally. LRTK also integrates well with existing surveying workflows; coordinate data obtained are compatible with national geodetic systems and geoid heights, so results align with those from traditional methods. While some are wary of bringing new IT gadgets to the field, using the familiar smartphone reduces psychological resistance and fosters a natural acceptance of new technology.

In short, LRTK excels in low adoption barriers. Smaller training costs and reduced personnel risk make it an attractive option for DX (digital transformation) initiatives and encourage broader adoption.

LRTK Adoption Cases and Voices from the Field (Manpower Reduction, Safety, Reduced Implementation Costs)

Innovative LRTK smartphone surveying is already being adopted at construction sites and local governments nationwide. Below are noteworthy cases and field feedback focusing on manpower reduction, safety improvements, and cost savings.

【Disaster Response by Local Governments】 One local government promptly adopted an iPhone-based LRTK surveying system for disaster recovery fieldwork. Large-scale disasters can sever roads and communications, but LRTK can directly receive CLAS augmentation signals from Japan’s Quasi-Zenith Satellite System (Michibiki), enabling high-precision positioning even outside cellular coverage. Municipal staff measured positions of collapsed houses and ground deformations themselves and shared the data on the cloud immediately with related departments, speeding situation assessment and recovery work. Where previously they would have called specialist surveyors, they could now perform rapid in-house surveying, reducing costs. Staff reported that “being able to measure with satellites even when communications were cut was a major advantage” and “operation was simpler than expected and they could deploy it the same day.”

【As-Built Management on Construction Sites】 At a paving project, LRTK was used for as-built management. The site supervisor noted that “thanks to LRTK we could measure ground elevations across the surface before and after paving to check construction thickness, making finish-quality verification much more efficient.” Previously limited sampling risked missing defects, but full-site scanning with a smartphone eliminated gaps in quality control. Cloud sharing of survey data also removed the need to return to the office for recalculation, allowing immediate verification of construction results and contributing to schedule shortening and improved safety by reducing rework and re-entry into hazardous areas.

【Earthwork and Quantity Management】 On earthwork sites, LRTK’s point-cloud measurement and volume calculation functions received high praise. One field reported that using LRTK for progress management allowed them to provide heavy-equipment operators with volume and progress reports the same day. Where previously there were waits for the surveying team or office processing, site staff could now complete measurement through calculation on their own, smoothing operations and reducing idle time. Another report noted that even large fills (around 200 cubic meters) could be scanned and volume calculated quickly, easing site management and delivering manpower savings on large projects.

【Ease of Use and Portability Highly Praised】 Users frequently comment on the solution’s ease of use. One user posted that “the device is surprisingly light and small, small enough to fit in a chest pocket, which is extremely important; considering daily carry on site, this size is revolutionary.” Another said that “with the device mounted on a dedicated monopod one person could easily perform measurements; height correction was a one-button operation in the app,” praising one-person operation. Other comments included “I found the stake position just by following the smartphone guidance” and “taking a photo automatically records coordinates so report preparation is easier,” highlighting intuitive app operations enabling beginners to achieve high-accuracy results. Overall feedback from the field includes “easier than expected,” “we can do surveying in-house,” and “no surveying wait times, so operations are smoother.” LRTK appears to be steadily becoming a new standard tool on sites.

Conclusion: Encouraging the Adoption of Simplified Surveying with LRTK

Comparing conventional RTK-GNSS surveying equipment and the LRTK smartphone RTK solution shows LRTK’s advantages. It is accurate yet simple, multifunctional yet easy to use—LRTK has the potential to transform on-site surveying practices. In times of labor shortages and calls for work-style reform, smartphone-based surveying usable by anyone can be a trump card for manpower and labor savings. Completing surveying tasks internally rather than outsourcing to specialists can be a major strength, improving competitiveness through cost reduction and speed.

Of course, when actually introducing LRTK, consideration must be given to dividing roles with existing equipment and to site conditions. However, LRTK’s ease of trial adoption makes a phased introduction straightforward, lowering the barrier to taking the first step with new technology. Experiencing LRTK’s advantages on site and accumulating small successes makes transitioning to full-scale operation easier.

Concerns about complexity or cost will likely be pleasantly overturned by LRTK. The era in which “anyone can measure simply, safely, and with high precision using just a smartphone” has already begun. Consider trying LRTK for simplified surveying now; it may not be long before smartphone RTK becomes the next standard for promoting on-site DX and achieving manpower and labor savings.

FAQ (Frequently Asked Questions)

Q1. What reception conditions are required for GNSS positioning? A1. To perform RTK-GNSS positioning stably, a generally open outdoor environment with a clear view of the sky is required. To receive satellite signals sufficiently, an open area with few buildings or trees blocking the sky overhead is ideal. In areas such as city canyons between high-rise buildings or dense forests, the number of received satellite signals may decrease and multipath (reflected signal) interference may increase, making it difficult to obtain an RTK Fix solution. LRTK devices can receive multiple satellite constellations (GPS, GLONASS, Galileo, Michibiki/QZSS, etc.), giving them environmental robustness comparable to conventional equipment, but extremely restricted sky views or indoor environments still make high-precision positioning difficult. Conversely, in mountainous areas where cellular coverage is absent, if the sky is open, CLAS augmentation signals from Michibiki can enable positioning. For best results, measure in locations with a wide view of the sky and avoid obstructions when setting up a monopod.

Q2. Is there a difference in positioning accuracy between smartphone RTK (LRTK) and conventional RTK-GNSS equipment? A2. In favorable reception environments where an RTK Fix solution is achieved, smartphone RTK can attain centimeter-level accuracy equivalent to conventional equipment. Comparative tests have shown mean differences between LRTK and high-performance GNSS surveying equipment of only a few millimeters. Both systems typically offer nominal horizontal accuracy around ±2 cm and vertical accuracy around ±4 cm. However, smartphone RTK must also maintain an appropriate Fix state to realize this accuracy. If signal conditions degrade and the solution temporarily reverts to Float, the accuracy will deteriorate (errors of several tens of centimeters), similar to conventional equipment. For precise point measurements, it is essential to confirm a Fix state before recording. In summary, given suitable conditions, smartphone RTK performs comparably and is sufficient for routine surveying tasks.

Q3. Does LRTK support Michibiki’s CLAS? A3. Yes. LRTK devices support the centimeter-level correction service (CLAS) provided by Japan’s Quasi-Zenith Satellite System, Michibiki. Because CLAS signals can be received directly, high-precision positioning is possible in real time even in areas without cellular coverage, such as mountainous regions or at sea. This enables smartphone RTK to be used where conventional base-station communications were previously infeasible. LRTK also supports the internet-based Ntrip network RTK method, so in urban areas with communications you can receive corrections from existing reference station networks. In other words, LRTK offers the flexibility to perform high-precision positioning nationwide regardless of communication conditions by switching between CLAS and internet corrections as appropriate. Note that CLAS use requires that Michibiki satellites be visible in the target region (within Japan).

Q4. What are Fix and Float in RTK positioning? A4. Fix and Float are terms that describe the quality of the RTK-GNSS solution. Simply put, Fix is a resolved solution with centimeter-level errors, while Float is a preliminary solution that may still have errors of several tens of centimeters. RTK uses carrier-phase measurements for very precise ranging, and integer ambiguities must be resolved; when those ambiguities are fully resolved, the solution is called Fix, and an unresolved or partially resolved state is called Float. A Fix solution yields centimeter-level coordinates, whereas during Float the solution is unstable and may have errors in the 10–50 cm range. Typically, solutions switch from Float to Fix within several tens of seconds after starting, but if the number of satellites is low or signals are unstable, Fix convergence may take longer or the solution may revert from Fix to Float. In the field, the rule is to “record only after getting a Fix,” and LRTK apps clearly display whether the current solution is Fix or Float. If remaining in Float, move to a more open location, stabilize the monopod, or prolong the measurement (averaging) to encourage Fix acquisition. Once Fix is obtained, accuracy is maintained even while moving, so ensuring solid satellite capture to achieve Fix is key to high-precision surveying.