Reducing Survey Costs at Solar Power Plants｜Bringing Smartphone Surveying In-house with LRTK

Introduction: The Reality of Surveying Costs in Solar Power Plant Projects

Surveying work is indispensable in solar power plant construction projects. From on-site surveys to grasp terrain and boundaries, to staking out panel positions and checking foundation pile placements, to as-built measurements after construction is complete, surveying is required at every stage. In many cases, these surveying tasks are typically outsourced to specialized surveying companies or external technicians. However, in the context of solar power plants, outsourcing surveying often entails far greater costs and time than expected.

For example, even for small ground-mounted solar facilities, outsourcing surveys can cost tens of thousands of yen. For large projects, multiple surveys are needed—from initial investigations to stake-out during construction and final verification after completion—and costs accumulate each time. Because external surveyors are used, scheduling and delivery of deliverables can also take time, which can affect project progress.

This article proposes an in-house surveying solution using smartphones to address these surveying cost issues. In particular, by using the device “LRTK,” which enables centimeter-level positioning, anyone on site can easily perform highly accurate surveys. Let’s look at concrete methods and the effects of how this can solve cost and efficiency problems encountered at solar power plant construction and development sites.

Risks and Losses from Relying on Outsourced Surveying

First, let’s organize the common risks and losses that arise when surveying work is outsourced. While outsourcing provides the reassurance of entrusting specialists, the following disadvantages are often problematic on site:

• Increased cost burden: Contracting surveying companies is not cheap. Each additional survey or project extension incurs extra fees, squeezing the initial budget. Especially for small-scale projects, surveying costs often become a major factor that compresses profits.

• Difficulty in scheduling: You must coordinate dates according to the availability of the outsourced party, making rapid response difficult. Even when you need an urgent re-measurement due to design changes or on-site rework, the external team’s schedule may prevent immediate attendance, causing downtime that affects the construction schedule.

• No accumulation of in-house know-how: If surveying is always outsourced, company staff have no opportunity to acquire surveying skills. Always relying on external parties means no accumulation of experience or knowledge internally, leading to the loss of the ability to apply those skills in-house in the future.

• Rework due to communication errors: It is not easy to accurately convey site conditions and the points you want measured to an external party. Miscommunication can lead to survey results that differ from the intended scope. In such cases, additional re-measurement or data correction is required, resulting in duplicated work and costs.

Relying entirely on outsourced surveying thus carries not only cost and time losses but also the risk of failing to build technical expertise and information within the company. Recently, outsourcing costs have risen due to a shortage of specialized personnel such as surveyors, and the Ministry of Land, Infrastructure, Transport and Tourism’s *i-Construction* initiative has tended to increase the frequency of as-built management itself, making increased surveying costs an ever more pressing issue.

The Potential of Smartphone Surveying and Changing On-site Needs

Against this background, there is growing demand on site for "making surveying easier and faster". On solar sites in particular, which often cover vast areas and have varied terrain, rapid surveying and flexible responses are required. Thanks to recent technological advances, the familiar smartphone has attracted attention as a new surveying tool that can meet these needs.

One reason smartphone surveying has become feasible is the dramatic progress in positioning technology. GPS positioning used to have meter-level errors as a matter of course, but with correction technologies known as RTK (Real Time Kinematic) and Japan’s quasi-zenith satellite system Michibiki’s CLAS (Centimeter-Level Augmentation Service), centimeter-level high-precision positioning on smartphones is becoming a reality. Complementing this, compact high-performance GNSS antennas attachable to smartphones and the development of surveying-specific apps have progressed, making smartphone surveying that anyone on site can operate a practical option.

On-site needs have also changed significantly. Construction management, once reliant on paper drawings and manual workflows, is being digitized, and surveying data now needs to be integrated into CAD drawings and shared via the cloud immediately. Uses such as projecting design plans onto the actual site using AR (augmented reality) are also gaining attention. Smartphones are highly compatible with these digital tools; in addition to positioning, they provide value beyond simple measurements through camera- and LiDAR-based point cloud capture and geotagged photo records.

In short, for sites like solar power plants, the ability to "measure immediately when needed" and to "share and utilize measured data right away" has become a competitive advantage. Smartphone surveying is expected to be a compelling solution to meet those needs.

What LRTK Is: Enabling Centimeter-Level Positioning with a Smartphone

Now let’s explain specifically what LRTK is as a technology supporting smartphone surveying. LRTK is a compact GNSS system developed to enable centimeter-level high-precision positioning using a smartphone. Traditionally, full-scale RTK surveying required expensive GNSS base stations on tripods or pole-mounted receivers, but LRTK’s innovation is making such RTK surveying possible with a surprisingly compact device combined with a smartphone app.

An LRTK device fits in the palm of your hand and integrates an antenna, GNSS receiver, battery, and communication module all in one. For example, the smartphone-integrated model "LRTK Phone" has a receiver body that weighs about 125 g and is thin and lightweight, used by attaching it to a dedicated smartphone case. No cable connection is required, and it communicates wirelessly with the smartphone, allowing easy transport and operation without complicated equipment setups. The device is also designed with durability for field conditions, including water and dust resistance, making it reliable in harsh outdoor environments.

Regarding positioning accuracy, LRTK supports state-of-the-art GNSS technology and can achieve very stable high-precision positioning. Multi-frequency-capable receivers reduce error factors and can rapidly obtain a fixed solution (centimeter-level positional fix) in open-sky environments. Because it can receive Michibiki’s CLAS signals as mentioned earlier, there is the advantage of maintaining high accuracy even in mountainous or low-cellular-coverage areas using satellite-based augmentation alone. This addresses the issue of conventional RTK depending on cellular network communication and means consistent high-precision positioning is possible even at solar sites located in mountain areas.

Using the dedicated LRTK smartphone app, you can intuitively perform operations on the screen such as starting/stopping positioning, entering point names, saving acquired data, and sharing to the cloud. By tapping a button at the point you want to measure, coordinates such as latitude, longitude, and elevation are recorded and plotted directly on a cloud map. Plane rectangular coordinate conversions and geoid height calculations are automatically handled, so accurate survey results can be obtained even without specialized knowledge. In other words, LRTK has evolved RTK surveying, which was previously only manageable by specialists, into a familiar tool that can be used "anytime, anywhere, by anyone."

What You Can Do In-house (Site Surveying / Pile Positioning Guidance / Geotagged Photo Records / As-built Verification)

So, what concrete capabilities does in-house surveying with LRTK enable? Here are representative cases of surveying and measurement tasks expected at solar power plant sites and how smartphone surveying can address them.

• Site surveying (understanding terrain and boundaries): Measuring the terrain and site boundaries of a planned development site was traditionally left to professional surveyors, but with LRTK your own staff can handle it. Walk around the site holding a smartphone and press the positioning button at each required point to obtain precise coordinates for those locations. For sloped terrain, you can collect multiple points to compile simple longitudinal and cross-sectional data, or measure key points near boundaries to accurately plot site shapes on design drawings later. Because measurement results can be shared to the cloud in real time, the design team at headquarters could start drafting drawings the same day. Even for vast solar farms, you can quickly progress with as-built surveying without waiting days.

• Pile positioning guidance (marking design positions on site): When installing screw piles or support posts to secure solar panel racks, it is essential to place them exactly according to the design. With LRTK, you can perform on-site stake-out of pile locations based on the design coordinates. Preload the design coordinate data into the smartphone app, select the target point on site, and the screen will display distance and direction from your current position to the target. By following these directions you can identify the scheduled pile location within a few centimeters of error. Even existing piles or reference points hidden by vegetation can be found using the smartphone guidance as long as their coordinates are known. This lets a single field technician handle processes that previously required a surveying team to set batter boards or snap lines.

• Geotagged photo records (sharing site photos with location data): LRTK is also useful for linking location information to site photos for process management and reporting. High-accuracy positioning data from LRTK can be attached to photos taken with a smartphone and saved to the cloud, preserving exactly "which point" each photo corresponds to. For example, if you photograph the location of buried cable installations, you can later identify the precise positions. Photographing and recording each structural element during construction makes as-built inspection documentation and trouble investigation more effective. Records that combine photos and location data have persuasive value beyond paper logs and are very useful for sharing information between the field and the office.

• As-built verification (post-construction accuracy checks): As-built surveying to verify that construction was performed as designed is another area where in-house smartphone surveying delivers major benefits. You can immediately check in-house whether rack installation positions and heights match the drawings, or confirm that land grading levels match design elevations. By measuring key completed points with LRTK and comparing their coordinates to the design values, you can determine whether they fall within tolerance. If discrepancies are found, you can discuss corrective measures on the spot and address them, minimizing rework. Tasks that would ordinarily require outsourcing and waiting for a report can be completed on site, dramatically improving operational efficiency.

As described above, incorporating smartphone surveying with LRTK allows you to bring key surveying tasks in-house for solar power plant construction and management, proceeding quickly and efficiently. From site understanding to position staking, record-keeping, and inspection, smartphone surveying offers flexibility to support the full workflow.

Operational Image and Required Equipment, Personnel, and Workflow

Next, let’s organize an image of actual in-house smartphone surveying operations and the equipment, personnel, and workflows required. Introducing new technology may seem daunting, but in-house surveying with LRTK is surprisingly simple.

• Required equipment: Essentially, you only need a smartphone or tablet and an LRTK device. With the LRTK Phone, a dedicated case and receiver for the smartphone are provided as a set; attach it and turn on the power to start positioning. A telescoping pole or monopod (optional) can be convenient to stabilize height reference, but is not mandatory. You don’t need to carry tripods, large batteries, or cables like traditional surveying equipment, so equipment transport to site is easy. Having portable power banks for charging is also advisable for long work sessions.

• Required personnel and skills: A major advantage of smartphone surveying is that it does not require professional surveyors to operate. Field supervisors or construction managers can master the basic operations of the LRTK app with a short training session and begin using it on site. The UI is intuitive for those familiar with smartphones, and the app automatically handles complex coordinate calculations, so there’s no need to worry about difficult computations. While knowledge of surveying principles and coordinate systems is helpful, it is not essential. Vendors typically provide initial training and support, allowing staff to become proficient during implementation.

• Operational workflow: Surveying workflows using LRTK are very simple and flexible. Take the example of conducting a new site survey: go to the site, attach the LRTK device to your smartphone and power it on. Launch the dedicated app, receive correction data (via network or CLAS signal), and confirm that positioning is in the FIX state—i.e., centimeter-level accuracy is achieved. Then simply tap the on-screen button at each point you want to measure to record points sequentially. Add names or notes to each point as needed so you can easily identify what each data point corresponds to later. When finished, upload the data to the cloud with one tap so the office can review and use the data by the time the crew leaves site.

For stake-out during construction, import design coordinate data as CSV into the app in advance, select the target points on site, and follow the guidance to move and mark positions. For as-built verification, measure the points you want to check while referencing the design drawing and view discrepancies on the screen. In all cases, the feature that a single operator can complete tasks with a smartphone in hand is notable. There is no need for multiple people to set up equipment or align targets as with total station surveying, enabling safe solo operations. It’s a workflow that embodies the concept of "measure whenever you think of it," dramatically improving on-site agility.

Actual Implementation Effects: Changes to Cost Structure and Faster Operations

Now let’s summarize the expected implementation effects when smartphone surveying is brought in-house. Notably, this impacts cost structure and yields dramatic improvements in operational speed.

• Changes to cost structure: By introducing LRTK devices and handling surveys in-house, the recurring costs that were previously paid to subcontractors can be greatly reduced. There are initial equipment purchases and possible subscription fees for correction services (if using network RTK), but these are one-time or ongoing investments that typically pay back over the long term. On sites where surveying is frequently required, equipment costs can often be recovered after only a few saved outsourcing fees. Moreover, once you can perform surveys in-house, you can handle new projects without additional per-project costs, helping to level out variable expenses across projects. In other words, turning surveying costs into lower fixed costs stabilizes project budgeting and can improve profit margins.

• Operational speed improvements: In-house smartphone surveying dramatically improves time efficiency. When you need to "measure here now," you can act immediately and avoid work stoppages waiting on surveyors. Tasks that previously halted until a surveying team arrived can proceed. For example, if design changes require urgent pile position adjustments, you can measure the new location and evaluate countermeasures the same day, minimizing schedule losses. Real-time cloud sharing also eliminates the conventional lag of "several days from measurement to drawing updates."

These effects show up quantitatively as well. In one case, the initial investigation process that had been outsourced was shortened by more than 90% in terms of working hours after introducing smartphone surveying. In another instance, as-built inspection survey costs became almost zero through in-house handling, allowing funds to be redirected to other quality improvement measures. Effects vary depending on circumstances, but in any case it is clear that operations become both faster and cheaper—a welcome change for both field practitioners and management.

Common Concerns and the Reality (Accuracy / Usability / Integration with Other Tools, etc.)

When introducing smartphone surveying, various concerns and questions may arise from the field. Let’s address some common worries and explain the actual situation.

• Concerns about accuracy: Worries like "Can a smartphone really achieve sufficient accuracy?" are understandable, but LRTK’s positioning accuracy has already been demonstrated. In open environments, horizontal accuracy is typically within about 2–3 cm and vertical accuracy within about 3–5 cm. This level of accuracy is sufficient for typical civil engineering work and solar panel installation. In practice, RTK-GNSS has begun to be used on many construction sites for layout and as-built management, and it meets quality inspection standards. If even higher accuracy is needed, the app includes functions such as repeated measurements of the same point and averaging, providing risk mitigation options. The bottom line is that, with correct usage, accuracy concerns for smartphone surveying are largely unnecessary.

• Concerns about usability: There may be worries that unfamiliar equipment or software cannot be used effectively on site. However, LRTK’s app is designed with ease of use in mind so that anyone on site can operate it. Basic operations from starting/stopping positioning to recording points and sending data are one-touch, and menus are simple. Those comfortable with smartphones can understand the app in minutes. Traditional surveying equipment (total stations, etc.) required specialist knowledge and complex setup, but smartphone surveying significantly lowers the operational barrier. For added assurance, conducting in-house training and using vendor support during rollout will allow staff to become proficient through hands-on practice.

• Integration with other tools: You may wonder whether survey data can be used in your company’s design systems or other tools. Coordinates obtained with LRTK are stored in the cloud as numerical data and can be exported in CSV or common formats. Thus, you can import them into your CAD software to create drawings or overlay them with other survey outputs (e.g., orthophotos or point clouds from drone surveys). The LRTK cloud also provides visualization of survey points on web maps, so stakeholders can share location information without additional GIS software. As you push forward with BIM/CIM or DX in construction management, smartphone surveying data is flexible and expandable for future integration.

• Concerns about signal and communications: GNSS surveying uses satellite signals, so positioning may be unstable in tunnels or dense forests. However, solar installations are often located on open, sunlit land where satellite reception is generally good. As mentioned earlier, LRTK supports CLAS, allowing reception of correction information via satellite in mountain areas with poor cellular coverage. If certain points still cannot be measured, you can fall back on traditional tools like measuring tapes or levels as a flexible workaround. While not a universal solution for every scenario, smartphone surveying is practical for most solar site use cases.

Smartphone Surveying as the New Norm in Solar Development

Smartphone-based in-house surveying is rapidly becoming the new norm in solar power development. Some advanced contractors and equipment suppliers already equip all field staff with smartphone surveying devices to improve efficiency. The old assumption that "surveying must be outsourced to specialists" is breaking down, and an era in which anyone can measure whenever needed is approaching.

This shift is driven not only by the cost savings and speed gains discussed earlier but also by the construction industry’s overall digital shift. In solar power plant development, adopting modern technologies rather than relying on traditional methods increasingly determines business competitiveness. Implementing smartphone surveying can act as a catalyst for on-site DX (digital transformation). For example, real-time sharing of survey data speeds up responses to design changes, and accumulated as-built data can inform future maintenance planning—enabling a data-driven approach.

Additionally, younger field technicians tend to be comfortable with smartphones and app usage, which supports adoption. Many personnel feel motivated by using the latest tools, so smartphone surveying can help strengthen field capabilities and improve employee retention. As in-house knowledge accumulates through internalization, it contributes to staff development and organizational technical capability. This virtuous cycle means smartphone surveying is more than a simple cost-cutting measure—it is shaping up to become the next standard in the solar power business.

The Ease of Adoption and Appeal of LRTK for Simple Surveying

Finally, emphasize the ease of adoption that LRTK-based smartphone surveying offers. When introducing new technology, cost-effectiveness and on-site adoption are natural concerns, but LRTK keeps these barriers extremely low.

First, on price: compared to conventional high-precision surveying equipment, the LRTK series is set at a very accessible price range. While I won’t state specific figures here, RTK-GNSS equipment that once required investments in the millions of yen can now be obtained with a fraction of that cost using LRTK. This makes it feasible even for small and medium-sized companies to deploy devices on a "one unit per site" or "one unit per person" basis. The low initial cost threshold is reassuring to management.

Second, the simplicity of the adoption process. LRTK can be used immediately by attaching it to a smartphone straight out of the box—there is no need for complex setup or field calibration by specialists. Training is quick, and deployment to the field can be accomplished in a short period. A pilot rollout with one device to experience the benefits before scaling up is a practical small-start approach. Showing the device on site often sparks staff interest and the desire to try it themselves. That ease of use is a core driver of smartphone surveying’s spread.

Finally, consider the added value that comes from adopting LRTK. Beyond lowering surveying costs and speeding up work, the ability to "measure in-house" builds confidence and operational agility, inspiring teams to take on tasks previously outsourced. As on-site digitalization progresses, the productivity of solar power development projects as a whole can be elevated, creating room to seize new business opportunities.

Bringing smartphone surveying in-house is a powerful way for solar power operators to achieve both cost reduction and efficiency gains. At the center of this approach, LRTK stands out as a solution that is "simple, affordable, and high-precision," making adoption easy. Consider taking this opportunity to introduce smartphone surveying as the new norm in your sites. LRTK-enabled simple surveying will undoubtedly be a driving force to bring solar power plant development sites to the next stage.