RTK-GNSS comparison reveals! LRTK smartphone surveying enables manpower and labor savings

Table of Contents

• Introduction: Demand and challenges of RTK-GNSS, background of LRTK 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 verification, stakeout, volume calculation, AR guidance

• Strengths of cloud integration and real-time sharing

• Comparison of training cost and risk of dependence on specialists, and ease of adoption

• LRTK adoption cases and voices from the field (manpower reduction, safety, reduced implementation cost)

• Conclusion: encouraging adoption of simplified surveying with LRTK

• FAQ

Introduction: Demand and challenges of RTK-GNSS, background of LRTK emergence

In recent years, the use of GNSS (satellite positioning) has advanced in construction and surveying sites, and RTK-GNSS surveying, which can measure positions with high accuracy in real time, has attracted attention. Traditionally, surveying was dominated by large optical instruments such as total stations and dedicated GNSS receivers; while these achieve high accuracy, they also presented challenges such as heavy equipment requiring two-person teams. These precision instruments also require regular calibration and maintenance, resulting in significant costs for adoption and upkeep. On the other hand, general handheld GPS or smartphone-integrated GPS can have positioning errors of several meters (about 5-10 m (16.4-32.8 ft)), making them unusable for tasks that demand centimeter-level accuracy such as map creation or stakeout. Therefore, high-precision surveying required dedicated RTK-capable GNSS equipment, acquisition of correction information (error correction data) from a base station or via the internet, and expensive equipment plus advanced expertise.

Against this backdrop, the demand for “a new, easy way to achieve high-precision positioning” has grown. Chronic labor shortages on site and the aging and decline of experienced survey technicians have made new technologies that lead to reduced manpower and labor strongly desired. Emerging in this context is the smartphone-based LRTK smartphone RTK solution. This article concretely introduces the manpower- and labor-saving effects, cost efficiency, mobility, and training advantages that LRTK brings to the field by comparing conventional RTK-GNSS surveying equipment with smartphone RTK (LRTK).

What is RTK-GNSS?

RTK-GNSS (Real-Time Kinematic GNSS) is a surveying technique that corrects GNSS satellite positioning errors in real time to obtain position coordinates with centimeter-level accuracy. A single GNSS receiver alone typically yields errors of several meters due to atmospheric and satellite orbit errors, but with RTK a second receiver is set up as a base station (reference point) and the relative error between that reference point and the rover is calculated to correct the rover’s position. Correction data are sent from the base station to the rover via radio or mobile networks, and the rover performs computations to obtain highly accurate positions in real time. In RTK surveying, horizontal accuracy is typically about 2-3 cm (0.8-1.2 in), and vertical accuracy about 3-5 cm (1.2-2.0 in), meeting the precision required in surveying.

Conventional RTK-GNSS surveying systems consist of dedicated high-precision GNSS antennas and receivers, a controller, and sometimes communication modems or radio data links. In the field, a base station is first placed on a known point to start positioning, and the rover is carried to the points to be measured. High-precision RTK positioning requires a clear view of the sky to capture satellites, and immediately after starting positioning there is a slightly larger error state known as a Float solution, which converges to a stable Fix solution (integer-fixed solution) in tens of seconds. Once in Fix, centimeter-level coordinates can be obtained at each point. While conventional GNSS surveying equipment is robust and highly accurate, the full setup is expensive, operation requires specialized knowledge, and dedicated survey technicians often handle operation.

What is smartphone RTK?

“Smartphone RTK” is a general term for technologies and solutions that perform RTK-GNSS positioning using a smartphone. Recent smartphones include high-performance GNSS chips, and some models now support raw GNSS data collection and multi-frequency reception required for RTK. Thanks to these advances, centimeter-class positioning with a smartphone alone is becoming possible. However, due to antenna performance and reception environment limitations of typical smartphones, there are practical limits to accuracy, so combining a smartphone with a small external high-precision antenna/receiver device is effective for practical smartphone RTK.

From this idea was born the smartphone RTK solution centered on the LRTK Phone. By attaching a small RTK-GNSS receiver device to a smartphone (currently mainly iPhone), and integrating a dedicated app with cloud services, centimeter-level positioning comparable to conventional surveying equipment and a variety of measurement functions can be realized with a single smartphone. By leveraging the smartphone camera and LiDAR sensor, it is possible not only to measure position but also to perform 3D scanning (point cloud measurement), stakeout guidance, and on-site AR visualization—features that go beyond simple positioning. In other words, the era in which “a smartphone becomes a surveying instrument” has arrived. Tasks that once required carrying heavy equipment can now be done with a pocketable smartphone plus a small device, enabling each field technician to carry their own high-precision surveying tool and take measurements whenever needed.

:contentReference[oaicite:0]{index=0} *By attaching a small LRTK device to a smartphone, RTK positioning comparable to conventional equipment becomes possible*

Comparison of RTK-GNSS equipment and LRTK: functions / accuracy / cost / training / maintenance

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

• Functionality comparison: Conventional equipment specializes in surveying-specific functions such as high-precision single-point coordinate measurement and datum transformations. LRTK offers equivalent high-precision positioning plus a wide range of functions leveraging smartphone cameras and sensors, such as photo capture, point cloud scanning, and AR display. For example, LRTK can record coordinates and orientation on field photos simultaneously with positioning, or obtain a 3D terrain model while walking, meaning tasks that previously required separate equipment or processes can be completed with just a smartphone. Cloud integration provides data sharing and analysis features, giving LRTK the versatility of a platform, not merely a positioning device.

• Accuracy comparison: Both high-quality dedicated GNSS equipment and LRTK can achieve centimeter-level horizontal and vertical accuracy when obtaining an RTK Fix solution. Generally, conventional equipment’s accuracy and stability are well-established, but LRTK testing has confirmed positional differences of less than 5 mm compared to dedicated equipment, so there is no significant disadvantage in positioning accuracy. In open environments, LRTK can acquire Fix in about 20 seconds and maintain centimeter accuracy even while moving. Moreover, smartphone-based continuous area measurements can produce gap-free data acquisition, which in some cases provides advantages in overall accuracy control and quality assurance.

• Cost comparison: Dedicated RTK-GNSS equipment has high initial costs, and if you set up your own base station you need that equipment as well. Operational costs such as communication service contracts and equipment maintenance also apply. In contrast, LRTK leverages existing smartphones, so you only need a small device and app subscription, greatly reducing initial costs. Even without preparing your own base station you can use network RTK provided by agencies like the Geospatial Information Authority of Japan or the CLAS satellite augmentation signal described later, keeping additional expenses low. Instead of purchasing multiple expensive dedicated units, attaching devices to each user’s smartphone enables a “one person, one device” setup, so when considering immediacy and efficiency the cost performance is clearly favorable.

• Training (proficiency) comparison: Conventional surveying equipment requires specialized operation and considerable time for operator training, often resulting in tasks becoming dependent on veteran staff and long training periods for newcomers. LRTK’s smartphone app with intuitive Japanese UI is easy for anyone to operate without confusion, which is a major advantage. Basic positioning can be taught in a few minutes, allowing immediate field use. Even without specialized knowledge, following the app’s prompts yields high-precision results, enabling non-surveyors to become productive in a short time. Training costs and time to proficiency are dramatically reduced, lowering the barrier to internal staff development.

• Maintenance and operation comparison: Conventional equipment requires periodic inspection, calibration adjustments, and software updates, which demand maintenance effort. As precision instruments they have failure risks, and repairs may require manufacturer support. LRTK’s primary components are a small device and a smartphone, and software updates are easily performed via the app. Integrated devices with batteries and antennas reduce cables and minimize on-site setup problems. If a smartphone malfunctions, work can resume quickly with a spare smartphone, providing flexibility. Overall, the simpler configuration means lower maintenance costs and easy 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? Here are several key points explaining the mechanism.

First, LRTK makes it easier to complete high-precision surveying as a single-person operation. Traditionally surveying was typically done with two or more people, but by attaching LRTK to a smartphone and a monopod, one person can perform reference point surveys and stakeout tasks. With a dedicated monopod, height offsets (distance from the ground to the device) can be preset in the app, and the workflow is simplified to leveling with a bubble and taking the measurement. If stakeout that previously required two people can be done by one, the other person can be reassigned, creating flexibility in staffing. It also reduces the need to send two people into hazardous areas, improving worker safety.

Next, reduced work time and effort is another key point. LRTK initializes positioning quickly, and once Fix is obtained one can walk while continuously measuring points, enabling many measurement points to be acquired simultaneously while moving over a wide area. Where old methods required setting a tripod for each point and measuring one point at a time, now walking with a smartphone completes area data collection. For example, in height surveying of a large development site, instead of sampling a few points to infer terrain, smartphone RTK can capture a point cloud over the entire site and calculate cut-and-fill volumes on the spot. A single pass completes surveying, calculation, and recording, eliminating re-surveys due to missed points and office-side post-processing, thus drastically shortening total work time.

Additionally, real-time sharing and automatic cloud saving of survey data reduce intermediate tasks between the field and the office. Coordinates and point clouds obtained in the LRTK app can be synced to the cloud with one tap, enabling all stakeholders to view and use the data immediately. There is no need to bring data back on a USB or transcribe handwritten notes, providing administrative labor savings through digitalization. If cloud-based analysis and drawing generation are completed, handing off to specialist departments is minimal, streamlining the entire reporting workflow.

In this way, LRTK enables a system for surveying that is “fewer people, shorter time, no waste, and safer.” It is an effective measure against chronic workforce shortages and is attracting attention as part of work-style reform.

Use-case comparisons: as-built verification, stakeout, volume calculation, AR guidance

Let’s compare typical field tasks where LRTK smartphone surveying can be particularly effective against conventional methods.

• As-built verification (measuring post-construction shapes): Traditionally, to check ground elevation after paving or earthwork, limited points were measured with a level to estimate thickness, or staff measured several cross-sections fragmentarily with tapes or surveying instruments. Using LRTK, you can scan the entire construction area as a point cloud and record the as-built surface. In sites where LRTK has been introduced for as-built verification, supervisors report that “measuring ground elevations across the area before and after paving to check construction thickness has made quality checks dramatically more efficient.” Areas that were previously sampled can now be fully scanned by walking with a smartphone, eliminating missed inspections and enabling comprehensive quality control. Point cloud data can be used to extract arbitrary cross-sections in the cloud and generate color-coded error maps against the design model with one click, enabling immediate on-site as-built checks and quick decisions on rework.

• Stakeout and reference point setup: For stakeout and setting reference points on construction sites, conventional workflow required inputting plan coordinates into surveying instruments and locating targets by sighting through the instrument. Optical methods often required two people to set a prism, and even GNSS stakeout depended on controller values or audio guidance, requiring experience. LRTK’s app has a coordinate navigation (guidance) function that displays arrows and distances on the smartphone screen toward predefined target coordinates (reference points or stakeout positions). Simply following the screen guidance leads you to the target point, enabling centimeter-level stakeout by non-experts. Users report “I found the stakeout point just by walking with the smartphone guidance” and “I could perform the setup alone without getting lost,” confirming that anyone can easily perform stakeout tasks.

• Volume calculation (cut-and-fill measurement): LRTK excels at volume management for earthworks. Traditionally you had to survey before and after excavation or fill, compare point clouds in the office, and compute volume differences—sometimes requiring CAD skill and taking days to obtain results. With LRTK, scanning before and after on a smartphone and letting the cloud automatically compare point clouds yields instant volume calculations on site. One project reported that “by scanning before and after fill and computing difference volumes immediately, operators could receive instructions the same day,” enabling early correction of overfilling or excessive excavation and contributing to improved material control and shortened schedules.

• AR guidance and visualization of buried assets: LRTK is also powerful for AR-based construction support and buried asset management. Traditionally, locating underground utilities relied on markings and batter boards during careful excavation, and it was difficult to know the exact position after backfilling. LRTK can store point cloud data of buried pipes or 3D design models in the cloud with absolute coordinates, and display them in AR on a smartphone. For example, you can visualize the route of an underground pipe through a smartphone as if seeing through the ground, preventing loss of buried asset locations. Without leaving markers, AR enables precise location identification during re-excavation, preventing mistakes and improving safety. AR-based construction guidance is also convenient: importing design models into the app and projecting them into the real world can display slope lines for earthworks to prevent overcutting, or place a model at the sign installation location to check the finished appearance. Tasks that once relied on experienced judgment or repeated marking can now be intuitively instructed and verified with 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 through cloud integration. The hardware (device), app, and cloud service function as an integrated system, allowing seamless use and sharing of survey data and coordination among stakeholders. Once positioning or point cloud scans are completed on site, data can be synced to the cloud with one tap from the app. Uploaded positioning data are immediately plotted on the cloud map, and office staff or clients can view site results in real time via a browser login without special software.

On the cloud, coordinates and point clouds can be displayed in 2D maps or 3D views, and analyses such as distance, area, and volume calculations can be performed on the spot. Large point cloud datasets obtained in the field can be used to extract arbitrary cross-sections or overlapped with design data to generate color-coded error displays, all with cloud-side button operations. Tasks that used to require bringing data back to the office and processing on high-performance PCs with specialized software can now be performed online directly from the field. If needed, external share links to cloud data can be issued so contractors or clients without licenses or special viewers can check survey results on their PCs or tablets, which is a major advantage for recipients who don’t need specialized software or high-spec machines.

Real-time sharing also changes communication workflows. For example, if additional measurements are needed on site, the office can send new instruction point coordinates via the cloud, which will instantly appear on the field smartphone map and guide users to measure them. Conversely, the office can immediately create drawings or reports based on high-precision photos or point clouds uploaded by the field. In an environment where data are shared instantly, the time-consuming compilation and approval processes that used to take days are greatly shortened, dramatically improving overall efficiency.

Moreover, cloud + app integration enables fine-grained responses to on-site needs. The app can automatically assign sequential IDs and optional notes to measured points, digitizing notes on the spot instead of writing in paper field books and preventing human errors such as illegible handwriting or transcription mistakes. Photos are tagged with date, orientation, and coordinates, simplifying creation of photo registers. Uploading design drawings or BIM models to the cloud allows on-site apps to align coordinate systems and AR-display design models for comparison with as-built conditions, enabling immediate verification of deviations and instant decisions on corrective work—contributing to real-time quality control.

Thus, LRTK is not just a high-precision surveying instrument but a platform that smartens and streamlines the entire workflow through cloud and app integration. The end-to-end capability from data capture to sharing, analysis, and reporting represents the next-generation “smart surveying” style.

Comparison of training cost and risk of dependence on specialists, and ease of adoption

When introducing new technology on site, barriers include training costs and risk of dependence on specialists. Conventional surveying equipment requires experience to operate, so only a limited number of “qualified people” may exist in-house, and surveying can stop if those people are absent—this is the common dependence problem. New employee training also takes time and money, and a mindset that “surveying is for specialist departments” can hinder in-house skill development.

LRTK smartphone surveying greatly lowers these hurdles. With intuitive smartphone app operation, complex knowledge is unnecessary, so the system is usable immediately without special training. There are case reports that “with about five minutes of explanation, staff put the LRTK device in a pouch, went to site, and anyone could capture point clouds with one hand.” Regardless of experience level, people comfortable with smartphones can adopt the system smoothly. Once several people in a company learn the system, it can be quickly rolled out to others, enabling an organizational structure that is not dependent on a single expert. The risk of dependence decreases, and surveying skills are more likely to be retained within the organization even with personnel changes.

In terms of ease of adoption, low cost and technical entry barriers are major advantages. As mentioned, initial costs are much lower than for dedicated equipment, enabling a small-start approach with one set for trial. If effective, deployment can be scaled gradually. The coordinate data obtained are compatible with public surveying standards and support the Japanese geodetic system and geoid height, so results align with those obtained by conventional methods. Although some may be wary of introducing the latest IT gadgets on site, using familiar smartphones reduces psychological resistance, making it easier to accept new technology.

In summary, LRTK excels in low adoption barriers, with small training costs and reduced personnel risk, making it attractive for DX (digital transformation) initiatives and encouraging widespread adoption.

LRTK adoption cases and voices from the field (manpower reduction, safety, reduced implementation cost)

Innovative LRTK smartphone surveying is already being introduced at construction sites and local governments nationwide. Below are notable cases and field feedback regarding manpower reduction, safety improvements, and cost savings.

Disaster response by a local government A certain local government quickly adopted an iPhone-based LRTK surveying system for disaster recovery sites. In large disasters, roads and communication infrastructure can be severed, 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 collapsed house locations and ground deformation themselves and immediately shared the data on the cloud with relevant departments, speeding situation assessment and recovery work. Rather than calling specialist surveyors, they could survey quickly in-house, contributing to cost reduction. Officials commented that “being able to measure using only satellites when communications were cut was significant” and that “operation was easier than expected and the system could be deployed the same day.”

As-built management on a construction site On a paving project, LRTK was used for as-built management. The site supervisor said, “Thanks to LRTK we could measure ground elevations across the surface before and after paving to check construction thickness, and quality confirmation became dramatically more efficient.” Previously limited sampling risked missing defects, but full-area scanning by walking with a smartphone eliminated gaps in quality control. Sharing survey data in the cloud also removed the need for re-computation in the office, enabling quick verification of construction results. Ensuring quality while reducing rework helped shorten schedules and improved safety by reducing repeat entry into hazardous areas.

Earthwork and progress management On earthwork sites, LRTK’s point cloud measurement and volume calculation features have been highly praised. Field reports include “using LRTK for progress management of fill and backfill allowed instructions and progress reports to the machine operator the same day.” Previously there were waits for surveying teams or office processing, but site staff can now complete measurement and calculation themselves, smoothing work and reducing idle time while improving manpower efficiency. Another report said “even large fills (on the order of 200 cubic meters) could be scanned quickly to calculate volumes, making site management easier,” indicating contributions to labor saving in large-scale projects.

High marks for operability and portability Users often comment on the ease of use. One user posted on social media that “the device is astonishingly light and small, so it fits in a chest pocket and can be carried at all times—this is crucial; the size is revolutionary for on-site portability.” Another said, “with the device mounted on a dedicated monopod, one person could easily perform positioning; height correction was done with a single app button,” appreciating the ability for solo operation. Users also reported “I located stakeout points just by following the smartphone guidance” and “taking a photo automatically records coordinates, making report preparation easier.” Overall feedback from the field includes “easier than expected,” “we can perform surveying ourselves,” and “no more waiting for surveying teams, so work proceeds smoothly,” suggesting LRTK is steadily becoming a new standard tool on site.

Conclusion: encouraging adoption of simplified surveying with LRTK

Through comparison with conventional RTK-GNSS surveying equipment, we have seen the advantages of the smartphone RTK solution LRTK. High precision yet easy to use, multifunctional yet simple—LRTK has the potential to revolutionize field surveying styles. In an era of labor shortages and work-style reform, smartphone surveying that anyone can use may be the key to manpower and labor savings. Completing surveying tasks in-house with your own staff can be a major strength, leading to cost reductions and faster operations that improve competitiveness.

Of course, actual implementation requires considering how to partition tasks with existing equipment and adapting to site conditions, but LRTK’s ease makes trial adoption straightforward and lowers the initial hurdle to take the first step with new technology. Start by experiencing smartphone RTK on site, accumulate small successes, and gradually transition to full-scale operation—this progressive approach is appealing.

Concerns that new technology is difficult or costly are likely to be pleasantly overturned by LRTK. The era in which anyone can measure easily, safely, and with high precision using just a smartphone has already begun. Consider introducing simplified surveying with LRTK to promote on-site DX and achieve manpower and labor savings. The day when smartphone RTK becomes the next standard on site may not be far off.

FAQ (Frequently Asked Questions)

Q1. What reception conditions are required for GNSS positioning? A1. To stably perform RTK-GNSS positioning, a clear outdoor view of the sky is basically required. To receive sufficient satellite signals, an open area with few overhead obstructions such as buildings or trees is ideal. In downtown areas with high-rise buildings or dense forests, the number of received satellite signals can decrease and multipath (reflected signal) interference can increase, making it difficult to obtain an RTK Fix. LRTK devices can receive multiple constellations such as GPS, GLONASS, Galileo, and Michibiki (QZSS), so environmental robustness is high and comparable to conventional equipment, but extremely restricted sky views or indoor environments still make high-precision positioning difficult. Conversely, in mountainous areas without cellular coverage, if the sky is sufficiently open the Michibiki augmentation signal (CLAS) allows positioning. When surveying, choose locations with as wide a view of the sky as possible, and avoid nearby obstacles when setting up the monopod to improve accuracy.

Q2. Is there a difference in positioning accuracy between smartphone RTK (LRTK) and conventional RTK-GNSS equipment? A2. Under good reception conditions and with an RTK Fix solution, smartphone RTK can achieve centimeter-level accuracy equivalent to conventional equipment. Comparative tests measuring the same point with LRTK and high-performance GNSS surveying equipment show average differences within a few millimeters. Nominal accuracies such as about ±2 cm horizontally and ±4 cm vertically are comparable for both. However, smartphone RTK must also maintain an appropriate Fix state to achieve this accuracy. If signal conditions worsen and the solution temporarily reverts to Float, accuracy will degrade (errors on the order of tens of centimeters) just like conventional equipment. Therefore, for precise point measurements it is essential to confirm Fix status before recording. In summary, given proper conditions smartphone RTK offers comparable accuracy and is sufficient for everyday surveying tasks.

Q3. Does LRTK support Michibiki’s CLAS? A3. Yes, LRTK devices support Japan’s Quasi-Zenith Satellite System “Michibiki” centimeter-class augmentation service (CLAS). 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 means smartphone RTK can be used in situations where surveying was previously impossible due to lack of base station communication. LRTK also supports the Ntrip network RTK method via mobile networks, so in urban areas or other locations with connectivity it can receive corrections from existing reference station networks. In short, LRTK offers the flexibility to perform high-precision positioning nationwide regardless of communication environment, by switching between CLAS and internet corrections according to site conditions. Note that CLAS use requires Michibiki visibility in the target region (within Japan).

Q4. What are Fix and Float in RTK positioning? A4. Fix and Float are terms that indicate the quality of an RTK-GNSS solution. Simply put, Fix is a resolved solution with centimeter-level error, while Float is a provisional solution with errors of several tens of centimeters. RTK uses carrier-phase measurements from satellites for very precise ranging, and the integer ambiguities that arise must be resolved; a resolved state is called a Fix solution, and an unresolved or intermediate state is called a Float solution. When Fix is achieved, centimeter-level coordinates are obtained; during Float the solution is unstable and may include errors of 10–50 cm. Typically it takes tens of seconds after starting measurements to transition from Float to Fix, but when satellite visibility is low or signals unstable, Fix can take longer or revert to Float after being fixed. On-site the rule is “record after Fix is obtained,” and LRTK apps clearly display whether the current solution is Fix or Float. If still in Float, moving to a more open sky, stabilizing the monopod, or measuring for a slightly longer period (averaging) can help obtain Fix. Once Fix is obtained, accuracy is easier to maintain while moving, so acquiring a solid Fix is the key to high-precision positioning.