Challenges and Cost Issues of Outsourced Surveying

First, let's summarize the typical challenges that arise when outsourcing surveying tasks at construction sites. Generally, outsourcing surveying work can lead to the following issues:

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• High Cost Burden:Outsourcing surveying tasks to specialized companies can be expensive. If the frequency of surveying increases or project timelines extend, additional costs are incurred each time, increasing the risk of exceeding initial budgets. Even small-scale projects can incur hundreds of thousands of yen in outsourcing fees, significantly squeezing profit margins.

• Scheduling Difficulties:Arranging survey schedules must align with the availability of external surveyors, which makes it challenging to respond promptly. If quick surveying is required due to design changes or corrections, delays can occur depending on the subcontractor's schedule, potentially impacting the overall construction timeline.

• Lack of Internal Expertise Development:When surveying is outsourced, company technicians miss the opportunity to develop surveying skills. Continuous reliance on external providers prevents the accumulation of internal surveying knowledge, hindering future workforce training and technological advancement.

• Communication Gaps:Clear and accurate communication of site conditions and expected outcomes to external surveyors is crucial. Misunderstandings can lead to survey results that do not match expectations, requiring additional surveys or corrections and resulting in duplicated efforts.

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As described above, outsourcing surveying tasks presents challenges such as increased costs, lost time, and the inability to retain technical expertise internally. In particular, recent trends like rising survey costs due to a shortage of skilled personnel and increased frequency of surveying driven by the adoption of ICT-based construction methods have made rising surveying costs a significant concern for construction site management.

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Basics of RTK Positioning and Benefits of Implementation

Internalizing construction surveying using RTK positioning is gaining attention as a powerful solution to the challenges outlined above. RTK, short for "Real Time Kinematic," is a positioning technology also known as real-time kinematic surveying. While conventional GPS (single-point positioning) typically produces errors of several meters, RTK corrects these errors, achieving centimeter-level, high-precision positioning.

How RTK Works:RTK positioning simultaneously uses two GNSS receivers: a base station set at a known coordinate and a rover station that measures positions while moving. The base station receives satellite signals containing errors and transmits this error correction information to the rover via radio or internet communication. The rover then compares its own received data with the correction data from the base station in real-time, effectively canceling out the errors and providing highly accurate positional information.

Typically, RTK-GNSS positioning achieves approximately 2–3 cm accuracy horizontally and about 3–4 cm vertically, significantly more accurate than conventional GPS (single-point positioning), which typically has errors of several meters. Moreover, the accuracy generally improves as the distance between the base station and rover decreases, maintaining high precision within a range of about 10–20 kilometers.

Benefits of Internalizing Construction Surveying with RTK:Implementing RTK technology and conducting surveying internally offers several advantages, such as:

• Reduction in Surveying Costs:Once RTK equipment is introduced, subsequent surveying tasks can be handled internally by your employees, significantly reducing outsourcing expenses. Although initial investment in equipment is required, over the medium to long term, this will substantially decrease the overall costs previously paid for outsourced surveying. Projects requiring frequent surveying will particularly benefit, allowing companies to recoup their investments quickly.

• Improved Responsiveness and Speed:When there is an immediate need to perform measurements at the construction site, your own staff can instantly address the task using RTK equipment. Unlike outsourcing, there's no need to wait for schedule adjustments or personnel arrangements, helping to prevent project delays. By reducing interruptions caused by waiting for surveys, overall project timelines can also be shortened.

• Solo Operation and Labor Reduction:RTK surveying equipment (GNSS receivers) can be operated by a single individual. Unlike traditional surveying methods using a total station, RTK does not require multiple personnel for equipment setup and target handling. A single field technician can perform surveys simply by walking around with a rover device. This approach effectively addresses labor shortages and enhances safety, allowing smaller teams to conduct dispersed operations.

• Easy Digital Integration:Surveying data acquired via GNSS is collected digitally as coordinate data, making it straightforward to integrate directly into CAD drawings or 3D models. This data can easily be compared with design-stage information or utilized for quality checks during as-built management, directly contributing to digital transformation (DX) in construction. This approach significantly reduces reliance on manual note-taking in field notebooks, streamlining data management processes.

• Accumulation of In-House Expertise:By conducting surveying internally, your company accumulates surveying knowledge and develops skilled personnel. Experienced employees become valuable surveying specialists, ready to contribute effectively to other projects in the future. The confidence gained from being able to manage surveying independently, without relying on external surveying firms, contributes significantly to enhancing the overall technical capability of your company.

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As outlined above, internalizing construction surveying through RTK technology provides numerous advantages. High-precision positioning, previously the domain of specialized surveying companies, is now becoming increasingly accessible to on-site construction technicians thanks to smaller, more affordable equipment. In the next section, we will examine real-world examples where the adoption of RTK technology at construction sites has successfully reduced costs and shortened project durations.

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Practical Steps for Implementing RTK

Where should you start when using RTK positioning on-site? This section outlines specific steps to smoothly introduce and operate RTK, even for small-scale general contractors.

1. Equipment Preparation and Understanding Initial Costs:Begin by preparing the necessary equipment. The minimum requirements for RTK surveying are a GNSS receiver (rover) and a base station providing correction data. You can set up your own base station or contract a network-based RTK service (VRS method) using electronic reference points provided by the Geospatial Information Authority of Japan. If opting to establish your own base station, you’ll need an additional GNSS receiver and communication equipment (such as digital radios or low-power radios). The total cost of this equipment varies widely depending on the manufacturer and features, ranging from several million yen for conventional systems to more affordable options offered by recent products. It's important to grasp both the initial investment and any recurring monthly fees if opting for network-based RTK.

2. Establishing Survey Data Integration and Operational Systems:After preparing the equipment, establish practical operational procedures. First, decide on the installation location for your base station. If there are known points within your site (public reference points or pre-measured points), install the base station there. For network-based systems, although no physical base station setup is required, localization (coordinate corrections) is necessary to match correction data received by the rover with the site coordinate system. Additionally, set up a process for integrating collected survey data with internal drawings or 3D models. For instance, immediately importing survey results into CAD software to produce drawings, or sharing data via cloud systems with headquarters.Preliminary training for site staff is also crucial. Teach them basic equipment operations such as satellite signal acquisition, conditions for achieving fixed solutions, procedures for registering known points, and coordinate transformations. It's beneficial to start with trial runs to gain familiarity.

3. Operational Start and Confirming Precautions:Once operations begin, pay attention to several key points. Recognize that RTK relies on satellite signals, making surveying environments important. Open areas offer high accuracy, but positioning becomes unstable in tunnels, under elevated structures, or densely wooded areas due to limited satellite visibility. In such cases, use alternative surveying tools like total stations.If utilizing radio communications, consider signal range limitations (typically a few kilometers) and comply with frequency and power regulations. Network-based RTK can also face communication disruptions in mountainous areas without cellular coverage, so using portable radios or offline augmentation signals (such as CLAS, described later) as backup is advisable.Additionally, accurate position management of the base station is crucial. If moved, always recalibrate the base station by checking its coordinates against known points. Lastly, document operational guidelines internally and share troubleshooting procedures (e.g., checklist when fixed solutions aren’t achieved) to ensure stable and reliable positioning operations.

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By following the steps outlined above, even smaller companies can smoothly introduce RTK technology. Recently, many manufacturers offer extensive technical support, including training sessions and on-site assistance, especially beneficial for first-time RTK users. When your company lacks internal expertise, actively utilizing these resources without hesitation is crucial, enabling you to establish operational methods tailored specifically to your business needs.

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Introduction to LRTK

Finally, we introduce "LRTK," a next-generation RTK device ideal for small-scale businesses among various RTK equipment. LRTK is a compact RTK-GNSS system developed from a practical field perspective, effectively combining the advantages of both single-point positioning and relative positioning mentioned earlier. Its key features can be summarized into three main points:

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• Compact, Lightweight, and Highly Portable:LRTK transforms the traditional, cumbersome RTK setup—consisting of stationary base stations, rover poles, and external batteries—into a single, compact, handheld device. For example, the smartphone-integrated model "LRTK Phone" weighs only 125 grams and is just 13 mm thin, easily fitting into a pocket. This all-in-one design includes an antenna, GNSS receiver, battery, and communication module, enabling centimeter-level positioning accuracy within a single device. It eliminates the hassle of cable connections, instead using wireless pairing with smartphones. Designed for ease of handling on-site, the LRTK is also ruggedized for waterproof and dustproof performance, ensuring reliable use even in demanding construction environments.

• High Accuracy and Stable Positioning Performance:Despite its compact size, LRTK is equipped with cutting-edge GNSS technology. Its triple-frequency receiver significantly reduces multipath effects (signal reflection) and ionospheric errors, enhancing the stability of positioning. As a result, it quickly achieves a fixed solution (centimeter-level accuracy) in open areas and maintains a high success rate even under moderately challenging environmental conditions.Moreover, LRTK supports Japan's Quasi-Zenith Satellite System (QZSS), known as "Michibiki," and its Centimeter-Level Augmentation Service (CLAS). This capability enables high-precision positioning using only satellite augmentation signals, even in mountainous or offshore locations beyond cellular network coverage. Thus, LRTK maintains RTK-equivalent accuracy without relying on network-based VRS corrections, effectively balancing mobility and positioning precision in any field condition.

• Affordable Pricing and Ease of Operation:LRTK is designed to be affordably priced, making it accessible even for small and medium-sized businesses. Compared to traditional, expensive RTK equipment, the initial cost barrier is significantly lower, paving the way for widespread adoption—such as equipping each worksite or each worker with their own device.A dedicated mobile app enables intuitive operation directly from your smartphone screen. Starting and stopping positioning measurements, entering point names, and sharing collected data via the cloud can all be done with just a single touch, allowing even field staff without specialized knowledge to operate the system easily.Thus, LRTK transforms RTK surveying—which was once limited to specialists—into a practical tool that is accessible "anytime, anywhere, and by anyone."