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

Introduction: The reality of surveying costs at solar power plants

Surveying work is indispensable in construction projects for solar power plants. Surveying is required at every stage: on-site investigations to understand the terrain and boundaries of the site, staking out positions for panel installation and verifying the placement of foundation piles, and as-built measurements after construction completion. These surveying tasks are, in many cases, typically outsourced to specialized surveying firms or external technicians. However, in reality, outsourcing surveying for solar power plants often entails far greater costs and time than imagined.

For example, even for a small ground-mounted solar facility, outsourcing surveying can sometimes incur costs on the order of several hundred thousand yen. For large projects, multiple surveys are required—from initial surveys to staking out pile positions during construction to post-completion verification—and costs accumulate each time. Because external surveyors are used, scheduling and receiving deliverables also take time, which can affect the project schedule.

This article proposes in-house surveying using smartphones as a solution to such surveying cost issues. In particular, by using a device called “LRTK” that enables centimeter-level positioning, anyone on site can easily perform highly accurate surveys. Let’s look at concrete methods and effects for solving the cost and efficiency problems faced in construction and development sites for solar power plants.

Risks and losses caused by dependence on outsourced surveying

First, let’s organize the typical risks and losses that arise from outsourcing surveying work. While outsourcing provides the reassurance of leaving tasks to specialists, the following disadvantages are often problematic on site.

• Increased cost burden: Fees for contracting surveying firms are not cheap. Additional costs arise whenever the number of surveys increases or construction schedules extend, squeezing the original budget. In particular, for small-scale projects, surveying costs tend to be a major factor that reduces profit margins.

• Difficulty in scheduling: You must coordinate schedules to match the availability of the contractor, making rapid responses difficult. Even when design changes or mid-construction adjustments require “we urgently need this re-surveyed,” the contractor’s schedule may prevent an immediate visit, causing waiting time and affecting the construction timeline.

• No accumulation of in-house know-how: If you always outsource surveying, your own staff have no opportunity to acquire surveying skills. Constant reliance on external parties means experience and knowledge don’t remain in-house, leading to the loss of the ability to develop personnel who can apply these skills internally in the future.

• Rework due to communication errors: It’s not easy to convey the on-site situation or the exact points to be measured accurately to an outsourced party. Miscommunication can result in deliverables that differ from what was intended. In such cases, additional re-measurement or data correction is required, resulting in twice the work and twice the cost.

Relying entirely on outsourced surveying therefore brings not only cost and time losses but also the risk that technical knowledge and information will not be accumulated internally. Recently, outsourcing costs have risen due to shortages of specialized personnel such as surveyors, and the Ministry of Land, Infrastructure, Transport and Tourism’s *i-Construction* promotion has tended to increase the frequency of as-built management itself, making the growth of surveying costs an increasingly important issue.

The potential of smartphone surveying and changed on-site needs

Against this backdrop, there is growing demand on sites for “surveys to be easier and faster.” Especially in solar power sites, which often involve large areas and varied terrain, fast surveying and flexible responses are required. Advances in technology in recent years have brought attention to the smartphone—a familiar tool—as a new surveying method that can meet this need.

One reason the potential for smartphone surveying is expanding is the dramatic advancement in positioning technology. Traditionally, GPS positioning with errors of several meters was common, but recently correction techniques called RTK (Real Time Kinematic) and Japan’s quasi-zenith satellite system “Michibiki” with its CLAS (Centimeter-Level Augmentation Service) have made centimeter-level high-accuracy positioning possible even with smartphones. In parallel, compact high-performance GNSS antennas that can be attached to smartphones and the development of surveying-specific apps have progressed, making smartphone surveying a practical reality that anyone on site can handle.

On-site needs have also changed significantly. Construction management, which used to rely on paper drawings and manual methods, is being digitalized, and there is a demand for surveying data to be immediately imported into CAD drawings or shared via the cloud. Uses that project design plans onto the actual site for verification using AR (augmented reality) are also drawing attention. Smartphones have high compatibility with these digital tools and bring value beyond mere measurement, such as point-cloud measurement using cameras or LiDAR sensors and geotagged photo records.

In short, at sites like solar power plants, being able to “measure immediately when needed” and to “share and use measured data immediately” has become directly linked to competitiveness. Smartphone surveying is expected to be a powerful solution that meets these needs.

What LRTK is: the system that enables centimeter-level positioning with a smartphone

Now, let’s explain what “LRTK” is as the specific technology supporting smartphone surveying. LRTK is a compact GNSS system developed to enable centimeter-level high-accuracy positioning using a smartphone. The revolutionary aspect of LRTK is that it makes full-fledged RTK surveying—which previously required expensive GNSS base stations on tripods or receivers on long poles—possible with a remarkably compact device combined with a smartphone app.

LRTK devices are palm-sized and integrate an antenna, GNSS receiver, battery, and communication module all-in-one. For example, the smartphone-integrated model “LRTK Phone” has a receiver body weighing about 125 g and is slim; it is attached to a smartphone via a dedicated case. No cable connection is necessary, and it pairs wirelessly with the smartphone, allowing easy portability and operation without complex equipment setups. It is designed for durability in the field with waterproof and dustproof features, so it can be used reliably in harsh outdoor environments.

Regarding positioning accuracy, LRTK supports cutting-edge GNSS technologies and enables very stable high-accuracy positioning. A multi-frequency receiver reduces error sources, and in open-sky environments it can quickly achieve a “fixed solution” with centimeter-level accuracy. Because it can receive Michibiki’s CLAS signals mentioned earlier, LRTK has the advantage of maintaining high accuracy using only augmentation information from satellites even in mountainous or low-cellular-coverage areas. This solves the problem of conventional RTK’s dependence on mobile network communications and means consistent high-accuracy positioning is possible even at sites located in mountain areas such as solar power plants.

With the dedicated LRTK smartphone app, operations such as starting/stopping positioning, entering point names, saving acquired data, and sharing to the cloud can all be performed intuitively on the smartphone screen. Simply tapping a button at the point you want to measure records coordinates such as latitude/longitude and elevation and plots them directly on a cloud map. Transformations to plane rectangular coordinate systems and geoid height calculations are processed automatically, so accurate surveying results can be obtained without specialized knowledge. In other words, LRTK has evolved RTK surveying, formerly only manageable by specialists, into a familiar tool that can be used “anytime, anywhere, by anyone.”

What in-house surveying enables (site surveying / stake-out / geotagged photos / as-built verification)

Next, let’s look at concrete examples of what becomes possible by bringing surveying in-house using LRTK. Below are typical surveying and measurement tasks expected at solar power plant sites and how smartphone surveying can handle them.

• Site surveying (understanding current terrain and boundaries): Surveying the terrain and site boundaries of a development site was traditionally left to surveyors, but with LRTK your own staff can handle it. Walk around the site holding the smartphone and press the positioning button at needed points to obtain precise coordinates for each location. For terrain with elevation changes, you can measure multiple points to collect simple longitudinal and cross-sectional data, or record key points near boundaries so designers can accurately plot site shapes on drawings later. Because measurement results can be shared to the cloud in real time, the design team at headquarters could begin drafting the same day. Even for extensive solar power sites, on-site surveys can proceed quickly without waiting for days.

• Stake-out (marking design positions on site): When installing screw piles or support columns to secure solar panel racks, placement must follow the design positions accurately. With LRTK, stake-out to the design coordinates is possible. Preload the design coordinate data into the smartphone app (e.g., via CSV), select the target point on site, and the screen shows the distance and direction from the current location to the target. Following that guidance will allow you to identify the designated pile location within a margin of a few centimeters. Even existing stakes or reference points hidden by vegetation can be located using the phone’s guidance if their coordinates are known. This enables site technicians to cover processes that previously required a surveying team for batter boards and layout, often allowing a single technician to complete the work.

• Geotagged photos (sharing on-site photos with location info): LRTK is also useful when you want to link on-site photos to location information for process management and reporting. LRTK’s high-accuracy positioning data can be attached to photos taken with a smartphone and saved to the cloud, allowing you to accurately record “which point the photo shows.” For example, photographing the location of buried cables later makes it easy to find the exact position, and documenting each structure under construction with photos helps when preparing as-built inspection materials or conducting follow-up investigations during incidents. Records that combine photos and position data are far more persuasive than paper logs and are very convenient when sharing information between site and office.

• As-built verification (post-construction accuracy checks): As-built surveying after construction completion—verifying whether work was performed according to design—is another area where in-house smartphone surveying offers major benefits. You can immediately check in-house whether rack installation positions and heights match drawings or whether site grading elevations conform to design. Measure key points of completed work with LRTK and compare the coordinate values to design values to determine if they are within tolerances. If discrepancies are found, corrective measures can be considered and implemented on the spot, minimizing rework. Tasks that would normally require outsourcing and waiting for a report can be completed on site, significantly improving operational efficiency.

By incorporating smartphone surveying with LRTK, you can internalize the main surveying tasks in solar power plant construction and management and proceed more quickly and efficiently. From site understanding to staking, recordkeeping, and inspections, the flexibility to use one tool across the workflow is the appeal of smartphone surveying.

Operational image and required equipment, personnel, and workflow

Now let’s outline the image of actual in-house smartphone surveying operation and the equipment, personnel, and workflow required. Introducing new technology may seem daunting, but surveying in-house with LRTK is surprisingly simple.

• Required equipment: Basically, you only need a smartphone or tablet device and an LRTK device. The LRTK Phone comes as a set with a dedicated smartphone case and receiver; attach it and turn it on to start positioning. Optionally, a telescoping pole or monopod can be useful for stabilizing height references, but they are not essential. Unlike conventional surveying equipment, you don’t need to carry tripods, large batteries, or cable assemblies, making transport to the site easy. Having a portable battery for charging is also recommended for long work sessions.

• Required personnel and skills: A major advantage of smartphone surveying is that it can be operated without a specialist surveyor. Site managers or construction supervisors can learn the basic LRTK app operations with short training and use it on site immediately. The UI is intuitive for anyone familiar with smartphones, and complex coordinate calculations are handled automatically by the app, so there is little cause for concern. Knowledge of surveying principles and coordinate systems is helpful but not mandatory. Vendors typically provide initial training and support, so you can get help during the adoption phase while your staff gain proficiency.

• Operational workflow: The survey workflow using LRTK is very simple and flexible. For example, for a new site survey, go to the site, attach the LRTK device to the smartphone, and power it on. Launch the dedicated app and receive correction information (via network or CLAS signal) to confirm the positioning is in a “FIX” state—i.e., centimeter-level accuracy is secured. Then simply tap the screen button at each point you want to measure to collect points one after another. Adding names or notes to each point makes it easy to identify what each dataset represents later. Measured data can be uploaded to the cloud with a single tap, so by the time you pack up, the office can already review and use the data.

For stake-out during construction, import design coordinate data into the app beforehand (e.g., CSV), select target points on site, and follow the guidance to move and mark points. For as-built checks, measure points against the design drawing and confirm differences on the screen. In all cases, a single operator can complete the work with a smartphone in hand. There is no need for multiple people to set up instruments or align targets as with total station surveying, allowing safe solo work. This “measure whenever it occurs to you” operational flow significantly improves field responsiveness.

Actual introduction effects: changes in cost structure and faster operations

Now let’s summarize the expected effects of introduction when smartphone surveying is internalized. The most notable are changes in cost structure and dramatic improvements in operational speed.

• Change in cost structure: Introducing LRTK devices and handling surveying internally can drastically reduce costs that were previously incurred as outsourcing fees. Of course, there are initial equipment purchases and possibly communication service fees (for network RTK), but these are investments that can be paid off over the long term. On sites where surveying is frequent, you can often recoup the equipment investment after only a few avoided outsourcing jobs. Moreover, once you have the capacity to survey in-house, you can respond to new projects without additional per-project costs, smoothing out variable costs across projects. In short, by turning surveying costs into fixed, lower costs, you gain budgetary stability across projects and improve profit margins.

• Speed of operations: In-house smartphone surveying dramatically improves time efficiency. When you want to “measure this right now,” you can act immediately, eliminating work stoppage caused by waiting for surveys. Tasks that previously had to pause until a surveying team arrived can proceed without delay. For example, if a design change requires urgent pile position corrections, you can measure the new positions the same day and develop countermeasures, minimizing schedule loss. Cloud sharing makes data exchange between site and office real-time, eliminating the traditional lag of “several days between measurement and drawing updates.”

These effects show up quantitatively as well. At one site, introducing smartphone surveying reduced the time spent on initial survey work—previously outsourced to specialists—by over 90% in terms of work hours. In another case, as-built inspection costs were reduced to nearly zero after internalization, allowing resources to be reallocated to other quality-improvement measures. While the magnitude of benefits varies by situation, it is unquestionable that operations become faster and cheaper—a welcome change for both field personnel and management.

Common concerns and their realities (accuracy / usability / integration with other tools, etc.)

When introducing smartphone surveying, various concerns and questions may arise from field teams. Here we address common worries and their realities.

• Concerns about accuracy: “Can a smartphone really achieve the required accuracy?” is a valid concern, but LRTK’s positioning accuracy has already been demonstrated. In open environments, horizontal positioning errors are typically around 2–3 cm (0.8–1.2 in) and vertical errors around 3–5 cm (1.2–2.0 in). This level of accuracy is sufficiently practical for typical civil works and solar panel installations. Indeed, RTK-GNSS is increasingly used on many construction sites for layout and as-built management, producing results that meet quality inspection standards. If even higher accuracy is required, the app includes functions such as taking multiple measurements at the same point and averaging them as a hedge. In short, with proper use, concerns about accuracy with smartphone surveying are largely unfounded.

• Concerns about usability: Some may worry about whether new equipment or software can be used effectively on site. However, the LRTK app is designed with extreme simplicity so that anyone on site can operate it. Basic operations from starting/stopping positioning to recording points and sending data are one-touch, and the menus are simple. If you’re comfortable with smartphones, you can understand the app in maybe a few tens of minutes. In contrast, conventional surveying equipment (e.g., total stations) required specialist knowledge and complex settings; smartphone surveying greatly lowers this usability barrier. For added assurance, use initial in-house training and vendor support to practice in the field before full deployment.

• Integration with other tools: You may wonder whether the survey data obtained can be used in your company’s design systems or other tools. Coordinates acquired with LRTK are stored as numerical data in the cloud and can be exported as CSV or common formats. Therefore, you can import them into your CAD software for drawing, overlay them with other survey results (e.g., drone orthophotos or point clouds), and analyze them easily. LRTK’s cloud visualizes survey points on a web map, so even without additional GIS software, stakeholders can share location information. For future BIM/CIM and DX initiatives in construction management, data interoperability from smartphone surveying is flexible and highly extensible.

• Concerns about radio/communication environments: GNSS surveying relies on satellite signals, so positioning can be unstable in tunnels or dense forests. However, solar power sites are typically in open, sunny areas where satellite reception is generally good. Also, as mentioned, LRTK supports CLAS, so correction information can be received via satellite even in mountainous areas with poor cellular coverage. If certain points are still unmeasurable, simple alternatives such as tape measures or levels can be used in combination. Although it’s not a perfect solution for every situation, smartphone surveying is practical for most scenes in solar power site applications.

Smartphone surveying as the new norm in solar development

Smartphone-based in-house surveying is becoming the new norm in solar power development. Some forward-thinking contractors and equipment vendors already equip all field staff with smartphone surveying devices to improve efficiency. The old assumption that “surveying must be outsourced to specialists” is beginning to break down, and an era is approaching where anyone can measure when needed.

Behind this shift are not only the cost savings and speed benefits discussed earlier but also the construction industry’s broader digital transformation. In solar power development, adopting the latest technologies instead of sticking to traditional methods increasingly affects competitiveness. Introducing smartphone surveying can act as a catalyst to accelerate on-site DX (digital transformation). For example, real-time sharing of survey data enables faster responses to design changes, and accumulated as-built data can inform future maintenance planning—enabling data-driven operations.

Additionally, a growing number of younger field engineers are comfortable with smartphones and app usage, which supports adoption. Many personnel are motivated to use the latest tools, and introducing smartphone surveying may help strengthen on-site capabilities and improve staff retention. Internalizing surveying capability also accumulates know-how within the company, contributing to human resource development and boosting organizational technical capacity. This virtuous cycle makes smartphone surveying more than a mere cost-cutting measure; it will likely become the next standard for solar power businesses.

The simplicity of LRTK-based quick surveys and the appeal of easy adoption

Finally, let’s emphasize the appeal of LRTK-based smartphone surveying’s ease of adoption. When introducing new technology, return on investment and on-site adoption are natural concerns; LRTK keeps these hurdles exceptionally low.

First, from a price perspective, the LRTK series is set at a highly accessible range compared to conventional high-precision surveying equipment. While specific prices are omitted here, RTK-GNSS equipment once required investments in the millions of yen; LRTK is available at a fraction of that cost. This makes it attainable for small and medium-sized companies, enabling operational models like “one device per site” or “one device per person.” The lower initial cost is a major reassurance for management.

Second, there is ease of the introduction process. LRTK works straight out of the box—attach it to your smartphone and you can immediately start positioning. Complex setups or calibrations by specialist vendors are unnecessary. As noted, operation is simple, allowing for rapid deployment on site. A small pilot deployment of one device can be used to evaluate effectiveness before scaling up—a practical small-start approach. When staff see the device in action, many will express interest and want to try it, demonstrating its approachability and accelerating adoption.

Lastly, consider the added value of introducing LRTK. Beyond lower costs and faster operations, having the confidence and agility to perform measurements in-house can inspire the company to take on tasks that were previously outsourced. As field digitalization advances, overall productivity in solar power development projects will be raised, creating room to seize new business opportunities.

In-house smartphone surveying is a powerful means for solar power developers to achieve both cost reduction and efficiency. At the heart of this is LRTK—a solution that stands out for being “easy, affordable, and high-accuracy” and is particularly attractive for its ease of adoption. Why not take this opportunity to introduce smartphone surveying as the new norm at your sites? There is no doubt that simple surveying with LRTK can become the driving force that takes solar power plant development to the next stage.